NISTIR 88-3848

Friability of Spray-Applied

Fireproofing and Thermal

Insulations: Laboratory

Evaluation of Prototype

Test Devices

Walter J. Rossiter, Jr., Willard E. Roberts, and Robert G. Mathey

U.S. DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

(Formerly National Bureau of Standards)

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

November 1988

Prepared for: General Services Administration

Safety and Environmental Management Division

Washington, DC 20405

TO Y»ri Amnca* Pregrvu

NISTIR 88-3848

Friability of Spray-Applied

Fireproofing and Thermal

Insulations: Laboratory

Evaluation of Prototype

Test Devices

Walter J. Rossiter, Jr., Willard E. Roberts, and Robert G. Mathey

U.S. DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

(Formerly National Bureau of Standards)

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

November 1988

National Bureau of Standards became the

National Institute of Standards and Technology

on August 23, 1988, when the Omnibus Trade and

Competitiveness Act was signed. NIST retains

all NBS functions. Its new programs will encourage

improved use of technology by U.S. industry.

Prepared for: General Services Administration

Safety and Environmental Management Division

Washington, DC 20405

U.S. DEPARTMENT OF COMMERCE

C. William Verity, Secretary

NATIONAL INSTITUTE OF STANDARDS

AND TECHNOLOGY

Ernest Ambler, Director

ABSTRACT

This report describes the results of the second phase of a study

to develop a field test method for assessing the friability of

spray-applied fireproofing and thermal insulating materials.

Phase 2 is the laboratory evaluation of the prototype devices for

conducting surface and bulk compression/shear, indentation,

abrasion, and impact tests. These tests were performed on

specially prepared fireproofing materials, produced to have a

range of friabilities. Differences in response of the test

samples to dislodgment or indentation were observed in the tests.

In the surface and bulk compression/shear tests, it was found

that, for a given type of material, as the density increased, the

torque level at which dislodging occurred increased. In the

indentation tests of the fibrous materials, the indentation depth

increased as their density decreased. However, little indentation

of the cementitious samples occurred regardless of their density.

In tests using the abrasion device, all samples left a residue

over the range of bearing forces examined. The amount of

residue, as determined by image analysis, was extremely variable,

and did not relate to the type or density of the material. With

regard to the impact tests, all samples underwent some amount of

indentation. The lower density fibrous materials experienced the

greatest depths of indentation.

The results indicated that the surface and bulk compression/shear,

indentation, and impact devices provided some measure of

discrimination between samples subjectively judged as having

"high" and "moderate" friability. In contrast, the abrasion

device was non-discriminating in that, for all tests, a residue

was produced. It was concluded that all devices be included in

the field phase of the study using in-place spray-applied

fireproofings having different levels of friability.

Key words: abrasion; asbestos-containing materials; compression;

fireproofing; friability; impact; indentation;

mechanical tests; shear; spray-applied; test devices;

test methods; thermal insulations

iii
TABLE OF CONTENTS

ABSTRACT

Page

iii

LIST OF TABLES

LIST OF FIGURES

1. INTRODUCTION

1.1 Background

1.2 Objective

1.3 Scope of the Study

2. PROTOTYPE TEST DEVICES FOR ASSESSMENT OF FRIABILITY

v | v

1

1

5

6

7

3

.

EXPERIMENTAL 9

3 . 1 Test Samples 9

3.2 Test Protocol 10

4.

RESULTS AND DISCUSSION 15

4.1 Comparison for Forces Applied by the Prototype Test

Devices With Forces Likely From Hand Actions 15

4.2 Operator Effects 15

4.3 Effects of Replicate Samples ..... 16

4.4 Surface Compression/Shear Test 16

4.5 Bulk Compression/Shear Test 20

4.6 Indentation Test 23

4.7 Abrasion Test 27

4.8 Impact Test 29

4.9 Cohesion/Adhesion Test ..... 31

5. SUMMARY AND CONCLUSIONS 34

6. ACKNOWLEDGMENTS 38

7. REFERENCES 3 9

APPENDIX A. PHOTOGRAPHS OF THE PROTOTYPE TEST DEVICES ..... A1

APPENDIX B. DESCRIPTION OF THE SURFACE AND BULK TEST DEVICES. . B1

B.l Description and Use of the Prototype Device for

Conducting Surface Compression/Shear Tests ....... B1

B.2 Description and Use of the Prototype Device for

Conducting Bulk Compression/Shear Tests B4

APPENDIX C. FORCES ASSOCIATED WITH HAND ACTIONS Cl

Introduction Cl

Hand Actions Compared to the Prototype Devices Cl

Comparison of Hand Actions with Prototype Devices. ... C3

C. 1

C . 2

C. 3

iv
LIST OF TABLES

Page

Table 1. Spray-Applied Materials Used in the Laboratory Tests . 40

Table 2. Descriptors of Levels of Friability Taken from the

EPA Algorithm Procedure, As Published in 1982 .... 41

Table 3. Descriptors of Levels of Friability Taken from the

GSA Algorithm Procedure 41

Table 4. The Friability Levels of the Samples as Subjectively

Judged 42

Table 5. Variables Examined in the Laboratory Tests 43

Table 6. Comparison Between Pass/Fail Points for the Fibrous

Materials, Determined in the Surface and Bulk

Compression/Shear Tests 44

Table Cl. Description of Hand Actions Compared to Prototype

Devices C5

Table C2 . Comparison of Maximum Hand Action Forces With the

Capacities of the Prototype Test Devices C6

LIST OF FIGURES

Page

Figure 1. Flow Diagram Indicating the Sequence of

Conducting Friability Tests 45

Figure 2. Results Using Prototype Device for Conducting

Surface Compression/Shear Tests. Tests Were

Conducted at a Bearing Force Level of

1 lbf (5 N) 46

Figure 3. Results Using Prototype Device for Conducting

Surface Compression/Shear Tests. Tests Were

Conducted at a Bearing Force Level of

2 lbf (10 N) 47

Figure 4. Results of the Surface Compression/Shear Tests:

Percent of the Test Squares Passed Versus Torque

Level 4 8

v
LIST OF FIGURES (continued)

Page

Figure 5. Results Using the Prototype Device for Conducting

Bulk Compression/Shear Tests 49

Figure 6. Results of the Bulk Compression/Shear Tests for

the Fibrous Samples: Percent of the Test

Squares Passed Versus Torque Level 50

Figure 7. Results Using the Prototype Device for Conducting

Indentation Tests 51

Figure 8. Results of the Indentation Tests Conducted at the

Surface Bearing Force Level 4. The Horizontal

Lines Represent Averages 52

Figure 9. Abrasion Test Results: Percent Area of the Felt

Covered by a Residue, As Determined by Image

Analysis . 53

Figure 10. Results Using the Prototype Device for Conducting

Impact Tests 54

Figure 11. Results of the ASTM E 736 Tests of the

Spray-Applied Samples 55

Figure Al. Prototype Device for Conducting Surface

Compression/Shear Tests A2

Figure A2 . Prototype Device for Conducting Bulk

Compression/Shear Tests A3

Figure A3. Prototype Device for Conducting Indentation Tests. . A4

Figure A4 . Prototype Device for Conducting Abrasion Tests ... A5

Figure A5. Prototype Device for Conducting Impact Tests .... A6
1 . INTRODUCTION

1 . 1 Background

The Public Building Service (PBS) of the General Services

Administration (GSA) has responsibility for the construction,

maintenance, and operation of many of the Nation's public

buildings. Some were constructed in the era when spray-on

asbestos-containing materials were extensively used in building

construction. At present, GSA owns approximately 1700 buildings.

In some of these buildings, GSA has assessed the conditions of

the asbestos-containing materials in the GSA-controlled buildings,

monitors changes in its condition over time, and recommends

appropriate abatement actions.

GSA prepared an algorithm-based procedure for use in the assessments

of its buildings that have asbestos-containing materials [1].

The GSA algorithm was developed on the basis of modifications and

additions to an earlier Environmental Protection Agency (EPA)

algorithm [2]. The GSA assessment procedure was intended to

"provide a relative index that indicates an overall risk potential"

[1]. The use of the algorithm allowed GSA to identify the

relative potential risk in the buildings with asbestos-containing

materials. It also allowed GSA to rank the results of the

condition assessments in a priority order for those buildings

needing abatement actions.

1
For purposes of asbestos control, a friable asbestos-containing

material is "any material containing more than 1 percent asbestos

by weight that hand pressure can crumble, pulverize, or reduce to

powder when dry" [3]. The GSA algorithm, as well as others [4],

assess the friability of the asbestos-containing material from a

subjective and non-defined test using the hand [5]. In the

algorithm-based procedures, friability is normally ranked in one

of four levels: high friability, moderate friability, low

friability, and not friable. Because of the importance of having

an objective ranking of the condition of the asbestos-containing

materials in its buildings, GSA proposed that the friability test

procedure using the hand should be replaced with a more objective,

quantitative procedure. Thus, GSA requested the National

Institute of Standards and Technology1 (NIST) to develop a field

test procedure for assessing and monitoring the friability of

spray-applied or troweled-on asbestos-containing materials.

This report describes the second phase of the GSA-sponsored study

for the test method development. The development of a quantitative

friability test method will assist GSA to:

o improve condition assessments of asbestos-containing

materials

,

o establish priorities for abatement programs,

o select appropriate abatement options, and

o monitor the change in friability of asbestos-containing

materials

.

1 . formerly the National Bureau of Standards (NBS )

.

2
The results of the first phase of the study have been reported

[5]. Phase 1 was limited to the development of the technical

bases for the field test method for assessing friability.

Included in the scope of Phase 1 was the development of a

conceptual model for determining the level of friability using

mechanical tests. The conceptual model considered hand actions

possibly used by field inspectors in friability determinations,

and the descriptors of levels of friability of spray-applied

asbestos-containing material given in algorithms.

A key task carried out in Phase 1 was the development of prototype

test devices (see Section 2 of the present report) for conducting

friability tests in the field [5]. Preliminary laboratory tests

using the devices were performed on specially prepared spray-on

mineral fibrous and cementitious fireproofings, which did not

contain asbestos but which were produced to have a range of

friabilities. The results suggested that the devices could

distinguish between degrees of friability of the test samples.

For example, for the fibrous materials included in the tests, the

force required to damage the samples increased as the sample

density increased.

The approach suggested in Phase 1 for development of a field test

method for assessing the friability of a spray-applied fireproofing

or thermal insulation is empirical. It was undertaken in

response to an urgent need for GSA to have available a field test

3
method that is not subjective. Ultimately, what is needed is to

relate the results of the measurements using the prototype

devices to the probability of releasing fibers or particles from

the sample into the air. Also, as previously proposed [5], it

may be useful to consider whether an indicator other than

friability would be useful for characterizing the potential of

the spray-on material to release fibers. Such properties might

include cohesive/adhesive strength of the material and fracture

mechanics properties such as the energy involved in fracturing or

deforming the material.

1.1.1 Use of Algorithms to Assess Friability

Algorithm procedures for assessing the condition of sprayapplied asbestos-containing materials were developed to provide a

method for predicting the potential for fiber release and

subsequent contamination of the building space [2,6,7]. The use

of algorithms for assessing the condition of in-place asbestoscontaining materials was reviewed in the Phase 1 report [5].

Eight factors, of which one is friability, are addressed in the

algorithm-based assessments. The review of algorithm procedures

in Phase 1 provided, in part, the basis for the prototype devices

for evaluating friability. As indicated earlier in the present

report, GSA originally developed the algorithm procedure as a

means for obtaining a relative index of the risk potential for

the buildings under its responsibility. At present, GSA makes

less use of the algorithm, because most of the buildings under

4
its responsibility have undergone assessments of sprayed-on

fireproofings and insulations using algorithm-based procedures 2

. Consequently, GSA now has placed emphasis on a need to have

available a non-subj ective field method for assessing friability

for use in abatement programs and in monitoring changes in

friability over time.

1 . 2 Obi ective

The overall objective of the study is to develop a field test

method to measure the friability of spray-applied fireproofing

and thermal insulation materials. The level of friability has

been associated with the potential of various types of sprayapplied fireproofing and thermal insulations containing asbestos

fibers to release materials into the building environment [8].

The objective of Phase 2 is to evaluate, in laboratory tests, the

performance of the prototype devices in distinguishing different

levels of friability of spray-applied fireproofing and thermal

insulation materials. The present report presents a summary of

the second phase. In Phase 3, field evaluation of the prototype

devices will be conducted by NIST and recommendations for the

field test method will be developed.

2 . Personal communication of W. Chan, GSA, to the authors

of the report.

5
1 . 3 Scope of the Study

The scope of Phase 2 was limited to laboratory testing of the

prototype devices. No field tests were conducted. The laboratory

tests were performed using the same non-asbestos-containing

materials obtained during the development of the prototype

devices. The major tasks performed in Phase 2 of the study were:

o Modification of the compression/shear test device to provide

for a uniform reproducible bearing force at which the device

is set in contact with the surface of the specimen during

testing

.

o Modification of the flow diagram proposed in Phase 1 to

reflect the need for GSA to have a field test method which

may be used in abatement programs and also programs monitoring

changes in friability over time.

o Development of a test protocol with the assistance of a

statistician in the NIST Center for Applied Mathematics who

provided advice on experimental design.

o Performance of the laboratory tests using the prototype

devices

.

o Analysis of the results with the assistance of the statisticia

who participated in the experimental design.

6
2 . PROTOTYPE TEST DEVICES FOR ASSESSMENT OF FRIABILITY

Figure 1 presents the modified flow diagram. The modifications

were based on discussions with GSA regarding a sequence for

conducting friability tests of spray-applied fireproofing and

thermal insulation. It is based on the flow diagram proposed in

Phase 1 for use with the GSA algorithm for assessing friability.

As is evident, five tests are included in the sequence: surface

compression/shear, bulk compression/shear, indentation, abrasion,

and impact. The development of prototype devices for conducting

the tests has been reported [5]. Appendix A provides photographs

of the prototype test devices including the modified torque

screwdrivers for performing surface and bulk compression/shear

tests

.

Appendix B describes the modified torque-screwdriver devices and

their operation in conducting the surface and bulk compression/shear

tests. The torque-screwdriver devices, as originally described

in the Phase 1 report [5], were modified after the report's

publication, and prior to conducting the Phase 2 laboratory tests

described herein. The device for the surface compression/shear

test was modified by the addition of a bearing plate and springloaded disk and fins (Figure Al)

.

This was to provide uniform

reproducible bearing force when the disk and fins are brought in

contact with the surface of the test specimen during application

of torque. The device for the bulk compression/shear test was

modified by providing the disk with the same number and configuration

7
of fins (Figure A2) as the surface compression/shear device.

However, the bulk compression/shear device has longer fins than

the surface compression/shear device.

The use of the flow diagram (Figure 1) is very similar to that

proposed in Phase 1 for assessing friability according to an

algorithm procedure. The key difference between the current and

previous flow diagrams is that, in following the revised diagram

to conduct tests, the results are not used to assign a classificati

of the level of friability to the material. The intent of the

revised diagram is to provide a sequence for conducting the

friability tests and recording the data which may be used by GSA

in ways such as comparing results for a series of buildings

(e.g., establishing abatement priorities), or monitoring changes

in a material for a given installation over time.

In using the flow diagram (Figure 1) for conducting field

assessments of friability of a spray-applied fireproofing or

thermal insulation, it is anticipated that tests would be

conducted in turn until a positive result was obtained (i.e., a

"yes" is produced) . However, in the Phase 2 laboratory study,

all five tests were conducted on each of the available samples.

8
3. EXPERIMENTAL

3 . 1 Test Samples

The spray-applied fireproofings, obtained during Phase 1 of the

study in the development of the prototype devices, were also used

in the laboratory program. These test samples included both

mineral fibrous and cementitious spray-applied materials (Table

1) . These materials were specially prepared by the suppliers in

an attempt to simulate the range of friability levels given in

the algorithms for the condition assessment of asbestos-containing

materials. This was to provide a basis for the range of friabilities

over which the test devices may be used. The densities [5] of

the test materials are given in Table 1. The dimensions of both

types of samples were 24 by 24 in. (600 by 600 mm) with a nominal

1 in. (25 mm) thickness of the fireproofing. The mineral fibrous

material was prepared on 1/2 in. (13 mm) drywall board. The

cementitious samples were spray-applied on 3/4 in. (19 mm)

plywood. The samples were placed on a rigid laboratory bench

during testing.

The spray-applied samples were examined manually according to the

algorithm-based directives for judging the friability of asbestoscontaining materials (Tables 2 & 3) . The friability levels

assigned to the samples, as based on the authors' judgment using

the descriptions defined in Tables 2 & 3, are given in Table 4.

Since the judgment was made using a subjective procedure, it was

possible that other investigators might have assigned other

9
friability levels. Three of the fibrous samples (FI, F2 , & F3)

were ranked in the "high friability" category; whereas the

remaining four samples (F4, Cl, C2 , & C3) were categorized as

having "moderate friability." None were considered as having

"low friability" or being "not friable."

3 . 2 Test Protocol

The laboratory tests were conducted using the following protocol:

o The series of tests with each device was performed by two

individuals so that the possibility of an operator effect

could be examined.

o Three replicate specimens of each of the seven samples (FI - F4 & Cl - C3) were used in each series of tests.

o The locations on the specimens for conducting the friability

tests were selected by dividing the 24 by 24 in. (600 by 600

mm) specimen surface area into a grid of small squares, each

3 by 3 in. (75 by 75 mm) . In the following sections of the

present report, the term "square" is used to denote the

small area of a specimen where a test was conducted. The

grid of squares was marked on the specimen surface using a

chalk line. The outer grid squares at the perimeter of the

specimen were not used in the tests to eliminate specimen

edge effects. The result was 36 usable squares per 24 by 24

in. (600 by 600 mm) specimen. A random pattern of selecting

individual squares for each given test was not used. The

same type of test (e.g., impact) was not conducted on two

adjacent test squares.

o The operation of the devices was as previously described

[5]. A summary of the variables examined for each of the

test devices is given in Table 5. (The test procedure used

with each device is given below in Section 3.2.1.)

o The cohesive strength of the test samples was measured

according to the procedure given in ASTM E 736, Standard

Test Method for "Cohesion/Adhesion of Sprayed Fire-Resistive

Materials Applied to Structural Members" [10].

o Data were recorded in a computer file and analyzed using a

statistical graphics program called "DATAPLOT" [11].

10
3c 2.1 Test Procedures Using the Prototype Devices . The test

procedures for the devices were as follows:

a) Surface Compression/Shear Test . In conducting this test, the

bearing force level (i.e., the force maintained normal to the

surface of the specimen while the torque is applied) at which the

fins of the device (Figure Al) were placed in contact with the

specimen surface was first set. Two bearing force levels, 1 and

2 lbf (5 and 10 N) , were chosen for this test program, and a

series of surface compression/shear tests was conducted at each

bearing force level. At the beginning of a series of tests, a

torque level for the screwdriver was arbitrarily selected. The

torque device was set on a specimen square, and the handle of the

screwdriver was manually rotated. For the pre-set torque level,

the specimen for a given square was designated as having "passed"

the test if it resisted the level of applied torque without

pieces dislodging (i.e., rotation of the handle occurred).

Conversely, for the pre-set torque level, the specimen for a

square was designated as having "failed" the test if pieces were

dislodged at a torque less than or equal to the setting (without

rotation of the screwdriver handle)

.

The torque setting on the screwdriver was increased or decreased

in successive tests until a "pass/fail point" was experimentally

determined for the specimen. The pass/fail point was associated

with the band of data within which the test results represented a

11
switch in the specimen's resistance to the level of applied

torque from primarily passing to essentially failing. It was

estimated as the "50 percent point," that is, the torque level at

which 50 percent of the specimens tested passed the test. The

pass/fail point was determined in one of two ways. First, it was

taken as the torque setting of the screwdriver at which replicate

determinations on test squares for a given specimen produced a

number of both passes and failures. Second, in cases where no

such torque setting was found, the pass/fail point was indicated

by the torque setting at which essentially all tested squares

passed, while at an incrementally higher setting, essentially all

the tested squares failed. In general, for each replicate test

specimen, the surface compression/shear test was conducted

repeatedly on different squares at varying torque settings of the

screwdriver until at least three failures and three passes were

recorded at the same or at incrementally consecutive settings.

(Three was considered the minimum necessary to have a measure of

reproducibility of the results.)

b) Bulk Compression/Shear Test . This test was conducted in a

manner similar to that for the surface compression/shear test in

that a pass/fail point was determined for each specimen. Thus,

an initial torque level on the screwdriver (Figure A2) was

arbitrarily set. The bulk compression/shear test device was set

on a test square such that the disk was flush with the specimen

surface with the fins penetrating the specimen. If the fins did

12
not totally penetrate the specimen, the test was not conducted.

The screwdriver handle was manually rotated. The pass/fail point

was again determined by increasing or decreasing the pre-set

torque level set on the screwdriver and observing whether the

specimen resisted the torque (i.e., continuous rotation of the

screwdriver handle was possible) or whether pieces of the

specimen were dislodged for each selected torque level.

c ) Indentation Test . In this test, the extent of indentation of

the foot of the device (Figure A3) into the specimen was recorded

as a function of the bearing force level applied on the specimen

surface. Four force levels, 4.5, 9, 13.5, and 18 lbf (20, 40,

60, and 80 N)

,

were used for the fibrous samples. The third

level, 13.5 lbf (80 N) , was not used for the cementitious samples

because of the limited number of samples. Three determinations

of indentation were made for each replicate specimen at each

bearing force level used.

d) Abrasion Test . This was conducted as a pass/fail test in

that the felt disc on the foot of the abrasion device (Figure A4)

was examined for the presence of a residue after its rotation on

the specimen surface. Before conducting the tests, all felts

were cleaned by hand-wiping to be seen visually free from fibers,

lint, particles and similar material. If a residue was observed,

then the specimen for a given test square was considered to have

failed. This criterion was selected consistent with descriptors

13
of friability concerning manual rubbing actions leaving powder or i granules on the hand (Table 2) . The variable investigated was

the bearing force level applied when the felt face of the

abrasion test device was set flush on the specimen surface. As

for the indentation tests, four bearing force levels, 4.5, 9,

13.5, and 18 lbf (20, 40, 60, and 80 N) , were used for the fibrous

samples. The third level, 13.5 lbf (60 N) , was omitted for the

cementitious samples.

In addition to indicating that the specimen for a given square

passed or failed based on the presence of a residue on the felt,

the percent area of the felt covered by residue was determined

using an image analysis technique [9]. This technique was a

laboratory procedure to quantify the area of residue and was not

intended for field use. Nevertheless, it could be applied to

field testing by analyzing, in the laboratory, felts removed from

the device or pictures taken of the felts.

e) Impact Test . The impact tests were conducted on the surface

of the specimens using three rubber tips of varying size and

hardness (Table 5) . For all specimens, the impact tests were

li performed in duplicate. The depth of the indentation produced in

the specimen by the impact device (Figure A5) was determined.

This measurement was made using a depth gage which could be read

to 0.1 mm. The depth measurement was made at the approximate

center of the indentation.

14
4. RESULTS AND DISCUSSION

4 . 1 Comparison for Forces Applied by the Prototype Test Devices

With Forces Likely From Hand Actions

Appendix C provides a comparison of the forces which could be

exerted by the prototype test devices to the maximum forces which

may be exerted by some hand actions expected to be used by field

inspectors in assessing friability of spray-applied fire-proofings.

As discussed in Appendix C, the forces which could be applied by

the prototype devices were within the range of forces generated

by the selected hand actions, and in most cases, comparable to

the maximum forces of the hand actions. The maximum hand forces

used in this comparison were exerted by 12 shop personnel

considered to have relatively strong hands (see Appendix C)

.

4 . 2 Operator Effects

All tests using the prototype devices were conducted by two of

the authors. This was to provide information on operator

effects. For all devices, examination of the plotted data (not

shown) clearly indicated no differences in results attributable

to operators. The authors conducting the tests were associated

with the development of the devices and thus considered to be

skilled in their operation. Further tests with a larger group

are required for a range of partially skilled (i.e., only briefed

on use of the devices) to determine whether an operator effect

exists for such individuals.

15
4 . 3 Effects of Replicate Specimens

As mentioned previously, all five tests were conducted in

triplicate using three 24 by 24 in. (600 by 600 mm) specimens for

each of the seven samples (FI - F4 and Cl - C3)

.

For each of the

five tests, no substantial differences in results among the

replicate specimens were found. Thus, in the discussion of the

results which follows for each type of test, no reference is made

to replicate specimens. Data for each of the five tests are

grouped together for each of the seven samples.

4 . 4 Surface Compression/Shear Test

The surface compression/shear tests were first conducted on the

fibrous samples using the torque-screwdriver device set flush on

the specimen surface at one of the two bearing force levels.

These levels, 1 and 2 lbf (5 and 10 N) , were considered to be

low, yet sufficient to allow the test to be conducted at a

reproducible bearing force. Based on the results for the fibrous

samples, the test was then conducted on the cementitious samples

at the bearing force level of 2 lbf (10 N) . (Sufficient cementiti(

sample was not available to allow the surface compression/shear

tests to be performed at both bearing force levels.)

The results of the surface compression/shear tests at the bearing

force levels of 1 and 2 lbf (5 and 10 N) are given in Figures 2

and 3, respectively. "Pass" indicates the specimen resisted the

torque applied, while "fail" indicates specimen material was

16
dislodged at a torque less than or equal to the set level

(Section 3.2). A comparison of the results in these figures for

the fibrous samples (FI - F4) shows that, as the bearing force

was raised from 1 to 2 lbf (5 to 10 N) , the torque required to

dislodge sample material (i.e. cause failure) increased. In

general, for each sample, the pass/fail point at the greater

bearing force (Figure 3) was about 1 unit of torque more than the

pass/fail point at the lower bearing force (Figure 2) . For

example, in the case of sample FI, when the bearing force was 1

lbf (5 N) , all tests resulted in failure at a pre-set torque

level of 2 lbf in. (0.2 N m)

.

However, when the bearing force

was 2 lbf (10 N) , about half the FI samples passed and half

failed at the 2 lbf in. (0.2 N m) torque level. The slight

upward shift in resistance to dislodging as the bearing force

increased was attributed to the increased compression of the

samples. However, the slight shift was not considered

significant, and it was decided that further testing (including

field tests) be conducted at the greater bearing force level of 2

lbf in. (0.2 N m)

.

A general benefit of the upward shift in the

specimen resistance to dislodging is that, for samples having low

resistance, the device would less likely be operated near its

lower limit of torque when using the greater bearing force.

From the results presented in Figures 2 and 3 , it is evident

that, for a given type of sample (fibrous or cementitious), as

the density of the samples (see Table 1) increased, the pass/fail

17
point tended to increase. This was attributed to the presence of

more binder in the samples of higher density. Having more

binder, the samples probably had higher cohesive and shear

strengths. The correlation between pass/fail point and density

was not perfect as shown by the observation that samples F4 and

Cl had comparable pass/fail points (Figure 3), although the

density of sample Cl was about 23 percent less than that of

sample F4 . This indicated that, for the different types of

materials in the study, density was not a correlation factor.

Figures 2 and 3 also show that the range of torque settings used

in the tests to establish a pass/fail point for any individual

sample was rather small. In most cases, only three or four

consecutive settings of torque were used. The maximum number was

five in the case of two cementitious samples, C2 and C3 (Figure 3

The finding that, for a given type of material, the sample

resistance to dislodging in the surface compression/shear test

increased with an increase in sample density was comparable to

the subjective observations regarding dislodging using the hand.

As summarized in Table 4, the samples appeared to increase in

resistance to dislodging by pinching with the finger tips as

density increased. This observation supports the premise that

the mechanical surface compression/shear device may be used in

lieu of the hand for determining a friability level for the

spray-applied fireproofing.

18
In conducting the series of laboratory tests, the torque level

was changed from one setting to another in determining the

pass/fail point for each of the specimens. An important question

was whether the surface compression/shear test device could be

used at a single torque level to distinguish between samples

considered of "high" and of "moderate" friability as subjectively

assigned (Table 4) to the samples in this study.

Figure 4 shows, for each of the seven samples, plots of the

percent of tests that passed at each pre-set torque level for the

series of tests conducted using a bearing force of 2 lbf (10 N)

.

The estimated pass/fail points are marked on these plots. Note

that, in each plot with the exception of C2 , the percent passed

decreased with an increase in torque level. In addition, it can

be seen that the torque levels used in the tests to establish the

pass/fail points of the samples increased in the series FI

through F4 and Cl through C3 . In Figure 4, the top row of plots

is for those samples subjectively assigned (Table 4) a level of

"high friability," whereas the middle and bottom rows are for

samples designated as having "moderate friability." It is

evident in Figure 4 that all test squares of specimens of

"moderate friability" tested at a torque level of 5 lbf -in. (0.6

4 N*m) passed the test. Only at torque levels above 5 lbf -in. (0.6

N*m) did failure of the "moderate friability" specimens occur.

Conversely, the majority of all test squares of specimens of

"high friability" tested at the 5 lbf*in. (0.6 N*m) torque level

19
failed the test. This finding suggested that a torque level of 5

lbf*in. (0.6 N-m) could be used to distinguish between the two

categories of samples in the laboratory study.

4 . 5 Bulk Compression/Shear Test

The bulk compression/shear test was only conducted on the fibrous

samples. The fins of the bulk compression/shear test device

could not penetrate the cementitious samples. In using the flow

diagram (Figure 1) to assess friability, it is considered that if

a sample could not be tested using the bulk compression/shear

device (and it passed the surface compression/shear test)

,

then

it should be evaluated using the indentation, abrasion, or impact

devices, in turn as necessary, to provide a friability level.

Unlike the surface compression/shear test device, the bulk

compression/shear device was not designed to have a collar for

setting the bearing force at which the fins and disk are placed

in contact with the sample surface. Based on considerations that

the device contained a relatively large bearing disk, it was

sufficient that the fins on the disk of the bulk compression/shear

device be able to penetrate the test sample as the face of the

disk is brought flush with the sample surface using the necessary

amount of manual force [5].

The results of the bulk compression/shear tests of the fibrous

samples are given in Figure 5. The trend in the data was

20
comparable to that for the surface compression/shear tests on the

fibrous samples in that, as the density of the samples increased,

the torque level at which dislodging occurred increased. Also,

the range of torque settings over which testing was performed to

determine the pass/fail point was again found to be rather small,

generally 3 or 4 settings of torque, suggesting that the laboratory

samples had somewhat uniform compression/shear resistance.

The range of torque settings over which the bulk compression/shear

tests were conducted on the four fibrous samples was from 2 to 30

lbf-in. (0.2 to 3.4 N*m) which reached the upper limit of the

device. This range was greater than that used to conduct the

surface compression/shear tests. As indicated in Appendix B, the

fin area for the bulk device is four times larger than that for

the surface device. Thus, an increase in torque range for the

bulk compression/shear tests was expected. For a given pre-set

torque setting, the force per unit fin area applied to the sample

through the fins of the test device is less in the bulk

compression/shear test than in the surface compression/shear

test.

Table 6 provides a comparison of the pass/fail points determined

on the fibrous samples in the surface and bulk compression/shear

tests. As given in Table 6, a greater spread between the

pass/fail points of each of the four fibrous samples was found in

the series of bulk compression/shear tests as compared to the

21
surface compression/shear tests. For example, in the bulk

compression/shear tests, the pass/fail points for samples F3 and

F4 were about 15 lbf-in. and 29 lbf-in. (1.7 and 3.3 N-m),

respectively, which is a difference of 14 lbf-in. (1.5 N-m), or

about a factor of 2. In contrast, for the surface compression/shea]

test, the pass/fail points for samples F3 and F4 were 5 and 6 lbfin. (0.6 and 0.7 N-m), respectively, or a difference of only 1

lbf-in. (0.1 N-m), or a factor of 1.2. An advantage in having

wider spreads between pass/fail points of different samples, as

observed for the bulk tests, is greater potential for distinguishing

between samples because of less possibility of overlap.

A key question to consider again is whether the bulk compression/sh

test may be used at a single torque setting to distinguish

between spray-applied materials of "high" and "moderate" friability

Figure 6 gives, for each of the fibrous samples, plots of the

percent of the specimen squares passing the test versus the preset torque setting. Note in Figure 6 that, for the limited data

in the study, a torque setting of about 20 lbf-in. (2.3 N-m)

provided a complete discrimination between samples assigned to

categories of "high" and "moderate" friability. In all tests of

the "high friability" fibrous specimens, a torque level below 20

lbf-in. (2.3 N-m) was found which produced 100 percent failure,

whereas for "moderate friability" specimens, some torque levels

slightly above 20 lbf-in. (2.3 N-m) were found that gave 100

percent passing.

22
4.6 Indentation Test

In using the indentation test device, the foot of the penetrometer

was placed on the surface of the test specimen [5]. Then, a

bearing force was manually applied until the collar of the device

was flush with the test specimen surface. The maximum bearing

force applied during testing was reached when the collar face

became flush with the test specimen surface. Adjustment of the

collar position along the length of the device housing resulted

in different test forces. In the present study, four bearing

forces were used as given in Table 5.

In conducting the indentation tests, the foot of the test device

indented the test specimen or caused retraction of the rod

supporting the device into the housing, making the indicator rod

extend [5]. The extension was an indication of the specimen's

resistance to indentation) . For example, if the indicator rod

extended fully, then indentation of the test specimen did not

occur.

For each specimen at the bearing force levels used, the indentation

test was generally conducted in triplicate. Bearing force level

three, 13.5 lbf (60 N) (Table 5), was not included in the tests

of the cementitious samples in order to conserve specimens. The

results of the indentation tests are given in Figure 7. The

indentation depth is given in "units," because the scale of the

indicator rod of the indentation device is not marked in increments

23
of length such as inches or millimetres 1 [5]. Use of the

indentation device with the amount of indentation given in

"units" was acceptable for this investigation. However, if the

device is to be used in common practice, then the scale should be

changed and marked in increments of length.

The results in Figure 7 indicated different behavior for the

fibrous and cementitious samples. In general, for the fibrous

materials, the higher applied bearing forces produced greater

depth of penetration. For these samples, the greatest indentation

was 2.25 units. This was achieved for the least dense sample,

FI, at a bearing force of 18 lbf (80 N)

.

The cementitious samples were found to be resistant to indentation

(Figure 7) . For all cementitious samples, the majority of the

measured indentations was 0.25 units. Little effect due to the

bearing force level was observed, although samples Cl and C2

experienced indentation of 0.50 units at the greater bearing

force levels (3 and 4) . Conversely, the lower bearing force

levels (1 and 2) produced no measurable indentation for some

measurements of all samples. The slight indentation (0.25 units)

found for the cementitious samples was primarily due to compaction

of the rough-texture material at the surface. The foot of the

1 . For the information of the reader, each unit of the

scale is about 0.3 in. (8 mm).

24
indentation device essentially underwent no penetration into the

bulk of the specimens.

The results of the indentation tests of the cementitious samples

may be considered with regard to the descriptor of a material

that is of "moderate friability" (Table 2) . This descriptor

states such materials are "easily indented by hand pressure."

A measured indentation of about 0.25 units was not considered

indicative of a sample that is "easily indented." It appeared

that the portion of the descriptor for "moderate friability"

regarding indentation by hand pressure was more appropriate to

the fibrous materials than the cementitious ones.

A consideration was whether the indentation test provided

discrimination between samples considered to be of "high" and

"moderate" friability. This is addressed in Figure 8 which is a

plot of indentation depth versus sample for the tests conducted

at bearing force level 4, and includes the average indentations

for each sample (the bold lines) . In addition, the upper portion

of the plot notes the assigned friability levels (Table 4) of the

samples. The average indentation of the samples assigned a "high

friability" level was greater than 1 unit, whereas those ranked

« in the "moderate friability" level had an average indentation of

about 0.5 units or less.

25
However, it was concluded that the indentation findings regarding

discrimination of the test samples had no relation to the

descriptors of levels of friability. As mentioned above, some

"moderately friable" materials are described as being "easily

indented by hand" (Table 2) . The selection of an indentation

depth of 0.5 units or less as the benchmark for "moderate

friability" would be illogical. The consequence of such a

selection would mean that a sample, assigned as having "moderate

friability" on the basis of being "easily indented by hand"

would, at the same time, have to exhibit little or no measurable

penetration in the indentation test.

The observation that samples in the study considered as having

"moderate friability" experienced little or no penetration using

the indentation device raises two questions. First, it may be

asked whether the indentation test is needed, and second, whether

the compression/shear or abrasion tests can provide the same

information. The data from the laboratory phase were too limited

to answer the questions. Specifically, no samples were available

in the study that were assigned the designation of "moderately

friable" on the basis of their resistance to indentation by hand.

It is considered that field testing will provide further data on

indentation of materials having a range of friability, as

assigned according to the descriptors in Tables 2 and 3.

26
4 . 7 Abrasion Test

The abrasion test was conducted at four levels of bearing force

in the case of the fibrous materials and three levels in the case

of the cementitious samples. Two replicate tests per sample were

conducted at each bearing force level. It was originally

intended to conducted triplicate tests, but the initial observations

of abrasion resistance indicated that failure was likely to occur

in all tests. Thus, the number of replicate tests was reduced to

two

.

The abrasion test is a pass/fail procedure in that any amount of

sample residue, found on the black felt covering the foot of the

test device through visual examination, is considered a "failure"

of the sample. The results of the series of abrasion tests

conducted on the study samples indicated that all failed. Every

test left some amount of residue on the felt. Because of the

light color of the samples, the residue could be clearly seen on

the black felt. The perception from the visual observations was

that the amount of residue left on the felts varied from slight

to considerable, but a pattern relating the residue amount to

either the type of material or the bearing force level could not

be discerned when examined by eye.

Image analysis was performed on the felts removed from the

abrasion test device to estimate the surface area covered by

residue. A minor amount of residue was lost from most felts in

27
detaching them from the foot of the test device. This was not

believed to have a major effect on the image analysis results of

percent area covered by residue. The results of the image

analysis are given in Figure 9 which consists of four plots of

the percent area of felt covered by residue in relation to the

type of test material. Each plot represents a bearing force

level at which the test device was set in contact with the sample

surface. As is evident in Figure 9, the area covered by residue

was found to vary from a little more than zero to over 90

percent. The variation in percent residue for many individual

samples was found to be wide, in some cases having an absolute

range greater than 50 percent (e.g., sample FI at load level 4).

The scatter was attributed to surface roughness effects in that

the foot of the abrasion device was not always in uniform contact

with the sample. Raised portions of the sample surface visually

appeared to be more susceptible to abrasion damage than those

sections having slight valleys or dips.

In general, the percent area of felt covered by residue was not

found to relate to the variables of either bearing force level or

type of material (Figure 9) . This finding was consistent with

the visible observations made during the testing. At best, the

percent area of residue may have increased slightly for the

cementitious materials at the higher bearing forces. The general

conclusion for the abrasion procedure was that the test was nondiscriminating between the samples in the study. This finding

28
was comparable to hand testing of the samples whereby each was

found to leave a residue when rubbed with the palm of the hand

(Table 4) . Although the method was non-discriminating, it may

still be important for showing ease of loss of fibers or particles

from the surface of a sample.

4 . 8 Impact Test

The results of the tests using the impact device are given in

Figure 10. The specimens under all test conditions underwent

some amount of indentation. Three different tips were used in

the test. Tip no. 1 was empirically selected when designing the

device such that the impact imparted would be somewhat comparable

to "forceful impact" (Table 2) using the hand [5]. In conducting

the series of tests described in the present report, the effect

of different tips on the resultant impact damage to the test

specimens was examined. Consistent with the descriptor of "low

friability," (Table 2), impact damage was measured as the depth

of indentation (impact depth) found in the tests.

Tip no. 2 was made of a rubber having the same hardness as tip

no. 1, but the size was smaller (Table 5). Thus, it was expected

that tests with tip no. 2 might produce greater impact depth,

because the impact energy would be more localized. Similarly,

tip no. 3 was the same size as tip no. 2, but it consisted of a

harder rubber. It was considered that tests with tip no. 3 would

produce greater impact depth (versus tip no. 2) , because less

29
energy would be dissipated through deformation of the rubber tip.

In the cases of both tip nos. 2 and 3, it was believed that the

changes in impact characteristics would not be drastic enough to

create a device imparting impact to the samples radically

different from using the hand.

It is evident from Figure 10 that the suppositions made in

selecting alternative test tips were only partly correct. In

general, as expected, tests made with tip no. 1 produced the

least impact depth (Figure 10) . However, little difference was

found between the impact depths measured for tip nos. 2 and 3.

Apparently, their hardness difference (Table 5) was not great

enough to produce a noticeable effect on impact depth for the

samples tested.

Another observation in Figure 10 is the groupings of impact

depths for samples FI, F2 , and F3 versus samples F4 , Cl, C2 , and

C3 . The impact depths for the former group are, on the average,

about 0.6 in. (1.5 cm), whereas they are about 0.3 in. (0.7 cm)

for the latter group. These two groupings correspond to the

friability rankings of "high" and "moderate" subjectively

assigned to the samples (Table 4) . This observation was comparabl

to that found for the indentation test device in that greater

indentation occurred with the samples ranked as having "high

friability." As in the case of the indentation device, no

significance was attached to the results.

30
The test results for the impact device produced no strong

evidence that would warrant selecting a rubber tip other than no.

1, which was used in the original design of the impact device.

All tips produced some indentation and the patterns for the

samples were comparable. Moreover, no practical reasons were

found during testing to change impact tips. Although the smaller

tips generally produced slightly greater impact depth, the

indentations given by the larger tip (no. 1) were generally

sufficient to be readily seen. It is suggested that field

testing of the device be conducted using the original tip.

4 . 9 Cohesion/Adhesion Test

ASTM E 736 is a standard test method for "measuring the

cohesion/adhesion or bond strength (tensile) perpendicular to the

surface of sprayed fire-resistive material applied to rigid

backing" [10]. The spray-applied fireproofing samples in the

present study were subjected to the ASTM E 736 procedure to

provide a comparison of the cohesion/adhesion results with those

obtained with the prototype devices for assessing friability. It

was considered that the determination of sample friability, as

examined using the prototype devices, might show a relationship

to the cohesion/adhesion strength of the test samples. As stated

4 in the ASTM E 736 standard, the method provides "an indication of

the ability of sprayed fire-resistive material to remain in place

and resist separation during anticipated service conditions."

This statement was considered consistent with the concept of

31
material friability which is taken as the ease of material

dislodging through crumbling or powdering under service condition;

In brief, the E 736 procedure involves adhering a plate with an

attached hook to the surface of the test specimen. One end of a

spring balance is connected to the hook and a force is manually

applied by pulling on the other end of the balance. The force at

which specimen failure occurs is recorded. The results of the

cohesion/adhesion tests are given in Figure 11. For all tests,

the failure of the sample was found to be cohesive, occurring

within the sample bulk. No failures occurred at the interface of

the samples and their substrates.

The results (Figure 11) indicated that, for both the fibrous and

cementitious materials, as the density increased, the cohesion

strength generally increased. One test of sample C3 produced a

much lower strength value of 34 lbf (151 N) than the other

measurements on this sample. Reasons for this observation were

not determined.

The pattern of increased cohesion strength with an increase of

density closely resembled the surface compression/shear results

obtained using the torque-screwdriver device (compare Figures 3

and 11) . Note, for example, that the pass/fail points for

dislodging the samples using the surface compression/shear device

were comparable for samples F4 and Cl, while the cohesion

32
strengths of these two samples were also found by the ASTM E 736

method to be similar. These results may suggest that the

compression/shear test provided an indirect measure of the

cohesion strength of the samples.

It is evident from Figure 11 that no overlap of cohesion strength

existed between the set of data for samples FI, F2 , and F3 , and

the set of data for samples F4 , Cl, C2 , and C3 . The values of

cohesion strength for all tests of samples FI, F2 , and F3 fell at

or below 14 lbf (62 N) , whereas the values for samples F4 , Cl,

C2 , and C3 were 20 lbf (89 N) or more. As indicated previously,

the former group of samples were categorized as having "high

friability," while the latter group were considered as having

"moderate friability." The discrimination of friability levels

found in the surface compression/shear tests (as well as the

indentation and impact tests) was also observed in the ASTM E 736

cohesion/adhesion tests.

33
5. SUMMARY AND CONCLUSIONS

This report describes Phase 2 of a study to develop a field test

method for assessing the friability of spray-applied fireproofing

and thermal insulating materials. Phase 2 was the laboratory

evaluation of the prototype devices for conducting surface and

bulk compression/ shear , indentation, abrasion, and impact tests.

These tests were performed on specially prepared fireproofing

materials, produced to have a range of friabilities. Differences

in response of the test samples were observed in the tests. The

test devices were designed to impart forces somewhat comparable

to those exerted by human hand actions that may be used by field

inspectors in conducting friability assessments.

The surface and bulk compression/shear devices measure the

resistance of a material to dislodgment as a function of the

level of torque set on the test device. For these two types of

tests, the patterns of the results were similar. It was found

that, for a given type of material, as the density increased, the

torque level at which dislodging occurred increased. For any

fibrous sample, the torque levels resulting in dislodging were

greater in the bulk compression/shear test than in the surface

compression/shear test. This was attributed to the larger fins

in the bulk device which consequently applied the compression/shec

action over a greater area (thus, providing lower localized

stress on the specimen) . Although the pattern of results for the

two compression/shear tests were similar, it was considered that

34
both tests should be evaluated in field testing. The reason is

that the surface and bulk properties of materials may have

different characteristics which could lead to two types of field

tests

.

In the case of the indentation device, a measurement of the depth

of indentation during testing is made. Here it was found that

the two types of material, fibrous and cementitious, had differing

behavior. For the fibrous materials, the indentation depth

increased as the density decreased. However, little indentation

of the cementitious samples occurred no matter what the density.

The abrasion device provides a measure of the sample's resistance

to being abraded in a rubbing type of action under a reproducible

bearing force. In the test, abrasion is indicated by the

presence of a residue left on the felt disk, i.e., the abrasion

surface of the device. It was found that all samples left a

residue over the range of bearing forces examined. The amount of

residue, as determined by image analysis, was extremely variable,

and did not relate to the type or density of the material.

Variable surface roughness of the samples may have contributed to

the wide scatter in the results.

When the samples were subjected to testing using the impact

device, all underwent some amount of indentation. The lower

density fibrous materials experienced the greatest depths of

35
indentation. A variable examined in the tests was the size and

hardness of the tip of the impact device. The results indicated

only a slight difference in impact depth for the large and small

diameter tips. The depth was greater for the small tip because

the impact energy was more localized on the sample. Because the

results were not significantly different, it was recommended that

the tip originally used in the design of the device be used for

field testing.

A question to be addressed by the laboratory program was whether

the devices could discriminate between materials having different

levels of friability. The samples in the study were subjectively

judged as having "high" and "moderate" friability. The results

using the prototype devices indicated that, for the study

samples, the surface and bulk compression/shear, devices provided

some measure of discrimination. Similarly, the indentation and

impact devices were somewhat discriminating. However, these

results were not considered significant. In the case of the

indentation device, the "moderate friability" samples were

essentially not indented under the test conditions. The finding

was not consistent with the descriptors of levels of friability

indicating that some "moderately friable" samples may be easily

indented. In contrast to the results with the surface and bulk

compression/shear, indentation, and impact devices, the abrasion

device was non-discriminating. All samples produced a residue in

36
the test which may be important for showing ease of release of

fibers of particles from the surface of a sample.

In conclusion, all devices evaluated in the laboratory phase

(Phase 2) of the study will be included in the field phase (Phase

3) using in-place spray-applied fireproofings. Field data are

needed to demonstrate the applicability of the devices for

determining friability of sprayed-applied fireproofings in

service. Results of the laboratory and field tests will be

compared. It is anticipated that fibrous and cementitious

materials will be included in the field phase, and thus will have

different levels of friability. The friability levels will be

classified according to the descriptors of friability given in

Tables 2 and 3. The buildings containing the spray-applied

fireproofings will be selected by GSA personnel.

37
6 . ACKNOWLEDGMENTS

This study was sponsored by the General Services Administration,

Safety and Environmental Management Division. The authors

acknowledge with thanks the assistance and encouragement provided

by the GSA project managers, W. Chan and J. Hensley. Appreciation

is expressed to the authors' NIST colleagues who contributed to

the conduct of the study. G. Frohnsdorff, L. Galowin, L.

Masters, L. Mordfin, and J. Pielert provided many critical

comments and suggestions during their review of this report.

N. Raufaste provided liaison between GSA and NIST. Special

thanks are extended to J. Lechner, NIST Statistical Engineering

Division, for his valuable assistance in designing the experiments

and in analyzing the test results, and also for his useful

comments and suggestions concerning their presentation in this rep

38
7. REFERENCES

1. "Asbestos," Chapter 10 in the GSA Manual, "Accident and

Fire Prevention - General," PBS P 5900. 2B, General Services

Administration (U.S.), Public Building Service (September 5,

1986)

.

2. "Asbestos Exposure Assessment in Buildings — Inspection

Manual," EPA-907/9-82-009)

,

Environmental Protection Agency

(U.S.), Region 7, Kansas City, Kansas (October 1982)

revised

.

3. "Guidance for Controlling Asbestos-Containing Materials in

Buildings," EPA 560/5-85-024, Environmental Protection

Agency (U.S.) (June 1985), Appendix C.

4. Lory, E.E. and Coin, D.S., "Management Procedure for

Assessment of Friable Asbestos Insulating Material,"

Technical Report R883, Naval Civil Engineering Laboratory

Port Hueneme, CA (February 1981)

,

220 pages.

5. Rossiter, Walter J. Jr., Roberts, Willard E., and Mathey,

Robert G. , "Friability of Spray-Applied Fireproofing and

Thermal Insulation: the Basis for a Field Test Method,"

NBSIR 87-3621, National Bureau of Standards (U.S.)

(December 1987)

,

58 pages.

6. "Guidance for Controlling Asbestos-Containing Materials in

Buildings," EPA 560/5-85-024, Environmental Protection

Agency (U.S.) (June 1985).

7. "Evaluation of Asbestos Abatement Techniques — Phase

I: Removal," EPA 560/5-85-019, Environmental Protection

Agency (U.S.) (October 1985).

8. "Identifying and Solving Asbestos Problems in Existing

Federal Buildings," Technical Report No. 77, Federal

Construction Council, Consulting Committee on Asbestos,

Washington, DC (1984), 83 pages.

9. Martin, Jonathan W. , Bentz, Dale P. , Kaetzel, Lawrence, and

McKnight. Mary E. , An Automated Maintenance Management

Program Part I: Quantitative Assessment of the Exterior

Condition of Metal Buildings and Roofing Systems via

Computer Image Processing," NBSIR 88-3719, National Bureau

of Standards (U.S.) (March 1988), 28 pages.

10. "Cohesion/Adhesion of Sprayed Fire-Resistive Materials

Applied to Structural Members," ASTM E 736, Vol . 04.07,

ASTM, Philadelphia, PA (1987).

11. Filliben, James J. , "Dataplot: An Interactive High-Level

Language for Graphics, Non-Linear Fitting, Data Analysis,

and Mathematics," Computer Graphics, Vol. 15 (1981)

pp. 199-213.

39
Table 1. Spray-Applied Materials Used in the Laboratory Tests

Densitva

Sample

No.

Material Type

lbm/ft3 kg/m3

FI Mineral Fibrous*3 8 128

F2 Mineral Fibrous 12 192

F3 Mineral Fibrous 17 272

F4 Mineral Fibrous 22 352

Cl Cementitious0 17 272

C2 Cementitious 19 304

C3 Cementitious 21 336

a. Values to which the materials were manufactured.

Measurements of the density indicated that individual specimens

were within 15 percent of the reported average density, except f<l|li sample No. FI which was within 25 percent [15]. 1 b. This material consisted of glass fibers with hydraulic binders

such as cements and plasters, mixed with water and spray-applied

c. This cementitious material consisted of a vermiculite and gypsum ' based factory-blended composite that, through the addition of wall

on the job site, forms a slurry for spray application.
ible 2. Descriptors of Levels of Friability Taken from the EPA

Algorithm Procedure, As Published in 1982 a

riability Level Descriptor

lot

riable

ow

riability

oderate

riability

igh

riability

Material that is hard and crusty. Cannot be damaged

by hand. Sharp tools required to penetrate the

material

.

Material that is difficult yet possible to damage by

hand. Material can be indented by forceful impact.

If the granular, cementitious asbestos-containing

material is rubbed, it leaves granules on the hand but

no powder.

Fairly easy to dislodge and crush or pulverize.

Material can be removed in small or large pieces.

Material is soft and can be easily indented by hand

pressure. The granular, cementitious asbestoscontaining material leaves a powder residue on the

hands when rubbed.

The material is fluffy, spongy, or flaking and may

have pieces hanging down. Easily crushed or pulverized

by minimal hand pressure. Material may disintegrate

or fall apart when touched.

This table is taken from Reference 2. It is noted that EPA no

longer uses an algorithm for assessing the condition of asbestoscontaining materials [6].

ble 3. Descriptors of Levels of Friability Taken from the GSA

Algorithm Procedure3

friability Level Descriptor

iOW

friability

[oderate

’riability

ligh

’riability

t. This table is taken from Reference 1.

Material that could be damaged by hand only if heavy

force is applied. This includes most troweled

materials

.

Fairly easy to dislodge and crush or pulverize by

hand. Material may be removed in small or large

pieces

.

The material is fluffy, spongy, or flaking and may

have pieces hanging down.

41
Table 4. The Friability Levels of the Samples as Subjectively Judged3 . Sample

No.

Assigned

Friability

Level

Comments

-

FI High

Friability

Pieces are readily pulled from sample by pinch

with the finger tips; sample is readily indent*

with a finger tip; fibers are easily dislodged

lightly rubbing with the palm of the hand.

F2 High

Friability

Observations are akin to those of sample FI,

although the resistance to dislodging appears

be slightly greater. Nevertheless, the hand

pressure used was still considered to be minim.

F3 High

Friability

Resistance to dislodging has increased in the

three modes used: pinching, indenting, and

rubbing. It is questioned whether the dislodg

is due to "minimal hand pressure" or "fairly

easy" to accomplish. To be conservative, the

level assigned is "high friability."

F4 Moderate

Friability

This sample has the most resistance of the

fibrous materials. Still, pinching removes

fibers from the surface fairly easily. Only

slight indentation occurs using a finger tip.

Fibers are abraded from the surface by rubbing

Cl Moderate

Friability

The surface texture is rough and irregular.

Surface protrusion of material can be pinched

away with the finger tips using pressure felt i be greater than "minimal hand pressure." The

surface may be indented with a finger tip.

Rubbing with the palm of the hand produces a

powdery residue.

C2 Moderate

Friability

Observations are akin to those of sample Cl,

except that the resistance to pinching and

indenting appears to have increased slightly.

Rubbing of the surface gives a powdery residue,

C3 Moderate

Friability

The resistance to pinching and indenting is

noticeably higher than that for sample C2

.

Indentation is slight with strong finger pressi

Hard rubbing of the surface with the palm of t\

hand produces a powdery residue.

a. The assignments were made by the report's authors.

42
ble 5. Variables Examined in the Laboratory Tests

st Variable

rface Torque Level: 1 to 10 lbf • in. in 1 lbf -in. increments

mpression/ (0.1 to 1.1 N* m in 0.1 N-m increments)

ear

Bearing Force Level

1 and 2 lbf

(5 and 10 N)

lk Torque Level: 2 to 30 lbf-in. in 1 lbf- in. increments

mpression/ (0.2 to 3 . 3 N m in 0.1 N m increments)

ear

dentation Bearing Force Level

Descriptor Value

Level 1 4.5 lbf (20 N)

Level 2 9 lbf (40 N)

Level 3 13.5 lbf (60 N)

Level 4 18 lbf (80 N)

rasion Bearing Force Level

Descriptor Value

Level 1 4.5 lbf (20 N)

Level 2 9 lbf (40 N)

Level 3 13.5 lbf (60 N)

Level 4 18 lbf (80 N)

pact Type of Tip: Descriptor Diameter Shore Hardness

No. 1 1.5 in.

(38 mm

)

Type 2A

,

65

No. 2 1 in

.

Type 2A

,

65

(25 mm)

1 in

.

( 2 5 mm

)

No. 3 Type 2A, 73
Table 6. Comparison Between Pass/Fail Points for the Fibrous Materials

Determined in the Surface and Bulk Compression/Shear Tests.

Sample Pass/Fail Point

No. Surface Torque Bulk Torque

lbf • in

.

(N • m) lbf • in . (N*m)

FI 2.0 (0.2) 2.5 (0.3)

F2 3.5 (0.4) 6.0 (0.7)

F3 4.7 (0.5) 15 (1.7)

F4 6.0 (0.7) 28-30 (3. 1-3. 3)

44
Figure 1. Flow Diagram Indicating the Sequence of Conducting

Friability Tests.

45
TORQUE,

IbWn.

1.2

1.0

0.8

0.6

0.4

0.2

0

FI F2 F3 F4 Cl C2 C3

SAMPLE

I £

10

o Pass

• Fail

8

DOOOOOM

COCO NOTE:

Surface torque tests were not

conducted at this bearing force

level on the cementitious samples

Figure 2. Results Using Prototype Device for Conducting Surface

Compression/Shear Tests. Tests Were Conducted at a Beari

Force Level of 1 lbf (5 N)

.

46

wN

di

lOaoj-
I

UHUUt,

IDT«in.

12

10

o Pass

• Fail

1.2

8

1.0

000000009

0000009 OO — 0.8

nm tjyrrrt iqqq

000000

OO

0.6

OODOOOOOOOO

rrrxTrjcrai coo 0.4

2 -< OO —OOODOOOO - 0.2

0

FI F2 F3 F4

SAMPLE

Cl C2 C3

Figure 3. Results Using Prototype Device for Conducting Surface

Compression/Shear Tests. Tests Were Conducted at a Bearing

Force Level of 2 lbf (10 N)

.

47

TORQUE,

N-m
PERCENT

PASSED

PERCENT

PASSED

Figure 4

.

Results of the Surface Compression/Shear Tests: Percent

the Test Squares Passed Versus Torque Level.

48
TORQUE,

IbHn.

30

25

o Pass

• Fail 3.0

20 -

GO

2.5

2.0

15 -

10

5 -

GO

OO

OOOOOOO*

o

NOTE:

Bulk torque tests were not

conducted on the cementitious

samples

- 1.5

1.0

FI F2 F3 F4

SAMPLE

Cl C2 C3

0.5

0

Figure 5. Results Using the Prototype Device for Conducting Bulk

Compression/Shear Tests.

49

TORQUE,

N-m
PERCENT

PASSED

PERCENT

PASSED

100

Figure 6. Results of the Bulk Compression/Shear Tests for the Fibr<

Samples: Percent of the Test Squares Passed Versus Torgi

Level

.

50
INDENTATION

DEPTH,

units

3.0

2.5

2.0

- OGD — CCD

- ouLfraa ooooga

1.0 -

0.5 -

coco

1.5 — ^

66

FI

LH MTTX3

rYWVws

Bearing Force Level

o 1 8 Ibf (80 N)

13.5 Ibf (60 N)

a 9 Ibf (40 N) • 4.5 Ibf (20 N)

0000

OOQLEDD

OOmYTi

nv

n

niimm occodcbcx* ooooooa

msm msm*

j^

F2 F3 F4 Cl

SAMPLE

C2 C3

Figure 7. Results Using the Prototype Device for Conducting Indentatio

Tests

.

51
INDENTATION

DEPTH,

units

3.0

2.5

2.0

1.5

1.0

0.5

0

Figure 8. Results of the Indentation Tests Conducted at the Bearinc

Force Level 4. The Horizontal Lines Represent Averages.

Assigned Friability: High Assigned Friability: Moderate

ooo

CO 0000

o GOOD

0000

00

ooood

00

000000

000 OOOOOOOO 000090000-

FI F2 F3 F4

SAMPLE

Cl C2 C3

52
100

80

60

100

40

- BEARING FORCE LEVEL 1: BEARING FORCE LEVEL 2: -

- 4.5 Ibf (20 N) - to

<D 9 Ibf (40 N) -

to m _ c

- • 8

—

- 9 — &

• • —

- •

•

•

•

•

•

•

•

•

• -

- llT 3

O

1

1

•

i

t

•

t

•

•

-

• •

!

•

cn

••

• 1

•

1

•

•

•

•

1 * t •

I

1 1

LU

DC t

•

• i

•

•

1 • ! 4 i

. 1 ! • 1 i FI F2 F3 F4 Cl C2 C3 FI F2 F3 F4 Cl C2 C3

- BEARING FORCE LEVEL 3: BEARING FORCE

•• -

u 13.5 Ibf (60 N) to

0) • LEVEL 4: 18 Ibf (80 N)

k03 •

• • •

• c

0)0

1

• •

• • •

-

••

• —

• •

•

••

•

i

1 _

-

• LU3

• -

• Q •

• •

- •

•

•• i

CO

LU

DC

•

1•

•

t

•

•

•

--

• 1 1 i i j i •

i i FI F2 F3 F4 Cl C2 C3 FI F2 F3 F4 Cl C2 C3

Figure 9. Abrasion Test Results: Percent Area of the Felt Covered by

a Residue, As Determined by Image Analysis.

53
IMPACT

DEPTH,

cm

3.0

2.5

2.0

1.5

1.0

0.5

0

FI F2 F3 F4 Cl C2 C3

a Large Gray Foot

o Small Gray Foot

Small Brown Foot

o

O

oo O

AO o O O 0

o o AO

A o o

A A A

AO O A

A

O A

O Q

a cm

O OO O COA

o AA ooo

o AA A oao COD — A AO A O

A A AA /W\ •

i

i i ^ i

i

I i

|

I I

SAMPLE

tF

I

Results Using the Prototype Device for Conducting Impact

Tests

.

Figure 10.
400

300

200

100

0

Figure 11. Results of the ASTM E 736 Tests of the Spray-Applied

Samples

.

55

COHESION

STRENGTH,

N

APPENDIX A. PHOTOGRAPHS OF THE PROTOTYPE TEST DEVICES

This appendix presents photographs of the prototype test devices

for conducting the surface and bulk compression/shear, indentation,

abrasion, and impact tests on spray-applied fireproofings and

thermal insulations. Figures A1 and A2 are photographs for the

modified surface and bulk compression/shear devices and have not

been previously published. The photographs for the indentation,

abrasion, and impact devices were previously presented in the

Phase 1 report [5].

A1
Torque screwdriver

Figure A1 . Prototype Device for Conducting Surface Compression/

Shear Tests

A2
Figure A2 . Prototype Device for Conducting Bulk Compression/

Shear Tests

A3
Figure A3. Prototype Device for Conducting Indentation Tests

A4
Figure A4 . Prototype Device for Conducting Abrasion Tests

A5
Tip

Figure A5. Prototype Device for Conducting Impact Tests

A6
APPENDIX B. DESCRIPTION OF THE SURFACE AND BULK TEST DEVICES

This Appendix presents descriptions of the modified surface and

bulk compression/shear devices. The indentation, abrasion, and

impact devices were used in the study as previously described

[5]. Their descriptions are not repeated here.

B. 1 Description and Use of the Prototype Device for Conducting

Surface Compression/Shear Tests.

The surface compression/shear device was developed based on the

use of a commercially available torque screwdriver. In this

study, the screwdriver was the model TS-30, manufactured by the

Utica Tool Co. Inc. 3 Torque screwdrivers are designed such that,

when torque is applied to the handle at a value below a pre-set

level, the handle and shaft of the driver rotate together. When

the amount of applied torque reaches the set level, an internal

clutch in the driver releases and the screwdriver handle turns

without rotation of the driver shaft. This limits the amount of

torque that may be applied to a screw or other object. The

torque screwdriver used for the prototype compression/shear test

devices could be set for maximum torque levels ranging from 1 to

30 lbf*in. (0.1 to 3.4 N«m) in increments of 1 lbf*in. (0.1 N *m)

.

3

. Certain trade names or company products are mentioned in

this appendix to specify adequately the experimental procedure

and equipment used. In no case does such identification imply

recommendation or endorsement by the National Bureau of

Standards, nor does it imply that the products are necessarily

the best available for the purpose.
In developing the test for the surface compression/shear properti^;

of a specimen, it was proposed to attach a disc with fins on its

face to the torque screwdriver. The disc could be pressed down

on the test material so that the fins would penetrate it. When

rotated, the fins would subject the material to compression and

shear forces. Dislodgment of the material would occur upon

rotation of the fins, depending upon the level pre-set level of

torque. If a low torque level was set, then rotation of the

screwdriver handle would occur and no dislodgment of the material

would take place.

To provide for a reproducible bearing force and to limit the

bearing force with which the fins of the disk would be set in

contact with the sample surface, the disk and fins were springloaded to the torque screwdriver. This was done through modifical.c

of a commercially available "pocket" penetrometer used for soil

testing. The penetrometer was the model H-4200, manufactured by

the Humboldt Mfg. Co. The unmodified penetrometer consisted of a

5/8 in. (16 mm) hex-shaped aluminum housing tube with a 1/4

in. (6 mm) penetration rod protruding from one end. This rod was

attached to a calibrated spring housed in the aluminum tube. The

calibration was in kg/cm2

. The end of the tube opposite the

penetration rod contained an indicator rod with graduation marks

every 0.25 kg/cm2 of load. This calibrated spring provided the

spring-loading and control of the bearing force of the surface

compression/shear device to the surface of the test sample. In

B2
modifying the penetrometer, the rod was made to rotate freely in

the housing.

To attach the penetrometer to the torque screwdriver, a 1/4 in.

(6 mm) hex-head shaft was welded to the indicator rod (Figure

Al)

.

This shaft was mounted in the bit holder placed on the end

of the torque screwdriver. The disk and fins for the surface

compression/shear device were attached to the penetration rod of

the modified penetrometer.

The disc for the surface compression/shear device was machined

from aluminum. It was 1.5 in. (37 mm) in diameter and 0.5

in. (13 mm) thick with four fins on the face side. The fins were

1/8 in. (3 mm) high and 1/2 in. (13 mm) long. They were 1/16

in. (1.6 mm) thick at the base and machined on one side of the

tips (penetration points) to a knife edge (45° bevel) . The

reverse sides of the 45° bevel of the fin tips were normal to the

disc when it was turned in a clockwise rotation (direction in

which the torque screwdriver turned) . The four fins were spaced

90 degrees apart with their outer edges being flush with the

outer edge of the disc. The disc was secured to the penetration

rod of the penetrometer using a small alien head screw.

A collar having a face 5 in. (126 mm) in diameter was placed

around the disk and fins. The collar configuration was such that

the disk and fins could retract into it and seat flush with the

B3
collar face. The position of the collar around the housing of

the penetrometer was adjustable in order to control the amount of

bearing force applied during surface compression/shear testing.

At any preset position of the collar, the maximum bearing force

was reached when the collar face became flush with test sample

surface

.

Because the configuration of the torque screwdriver was fixed, a

relationship existed between the torque level set on the screwdri'V]

and the amount of force applied by a fin of the surface

compression/shear device. The maximum force produced by the

compression/shear devices was derived from a simple calculation

based on the average distance from the center of the torque

screwdriver shaft to the center of the fins: the average force

per fin was about 0.5 lbf (2 N) per 1 lbf*in. (0.1 N-m) increment

of torque. In conducting friability assessments of the sprayapplied fireproofings, no attempt was made to determine the

forces or stresses in the test materials at the fins. Only the

torque set on the compression/shear device was recorded.

B. 2 Description and Use of the Prototype Device for Conducting

Bulk Compression/Shear Tests.

The prototype device (Figure A2) for conducting bulk compression/se

tests was also based on the torque screwdriver, model TS-30,

manufactured by the Utica Tool Co., Inc. The major differences

between the bulk and surface test devices were: (1)

the bulk device did not have a spring-loaded disk for bearing the

B4
fins on the sample surface, and (2) the fins of the bulk device

were longer to provide deeper penetration into the sample.

Thus, in developing the proposed test for the bulk compression/shear

properties of a specimen, a disc with fins on its face was

attached directly to the torque screwdriver. The disc could be

pressed down on the test material until its face was flush with

the sample surface, so that the fins penetrated the sample.

Depending upon the pre-set torque level, dislodgment of the

material would occur upon manual rotation of the screwdriver

handle. Depending on the resistance of the sample, if the torque

level was set relatively low, then rotation of the screwdriver

handle would occur and no dislodgment of the material would take

place. Conversely, at a relatively high torque level, dislodgment

would occur.

For the attachment of the disc (Figure A2) to the driver, a shaft

made from a 1/4-in. (6 mm) hex bit was secured on the back side

of the disc. This shaft was mounted in a 1/4-in. (6 mm) bit

holder placed on the end of the screwdriver. The disc used for

the bulk compression/shear device was machined from aluminum. It

was 4 in. (102 mm) in diameter and 1/8 in. (3 mm) thick with four

fins on the face side. The fins were 1/2 in. (13 mm) high, 1/2

in. (13 mm) long, and 1/8 in. (3 mm) thick. As was the case for

the surface compression/shear disc, the fins were also machined

to a dull knife edge (45° bevel) on their tips. For this disc,

the four fins were set 90 degrees apart with their outer edges

set 1 1/4 in. (32 mm) from the outer edge of the disc.

B5

APPENDIX C. FORCES ASSOCIATED WITH HAND ACTIONS

C. 1 Introduction

The maximum forces which the hand can impart for each type of

mechanical action used to assess friability needed to be considered

in setting limits of force in the mechanical tests. A review of

the literature regarding forces associated with hand actions

indicated that data on the subject were limited [5]. NIST

obtained the assistance of Professor K.H.E. Kroemer, Virginia

Polytechnic Institute and State University, Department of

Industrial Engineering, to conduct an initial study on hand

forces appropriate to the investigation of friability of asbestoscontaining materials. He prepared a report4 entitled, "Finger

and Hand Strength." This Appendix compares selected results of

Kroemer' s study to the capacities of the prototype devices.

C. 2 Hand Actions Compared to the Prototype Devices

As given in Tables 2 and 3 in the main body of this report, the

descriptors for levels of friability only reference hand actions

such as impact, rubbing, and indentation. As previously discussed

[5], other actions such as pinching and squeezing, pushing,

pulling, and scratching might be used by field inspectors to

assess friability. Prof. Kroemer measured the forces associated

with 11 hand actions. Five of these hand actions were selected

as having appropriate bearing to the mechanical actions of the

prototype devices. The five are: tip pinch, pad pinch, poke,

scratch or hook, and palm press. These action are described in

Cl

4 . Personal communication, Order No. 43NANB 712191,
Table Cl. Pinching was considered similar to the mechanical

action of the compression/shear test devices. Indentation was

taken comparable to a poking action with the finger or thumb,

while abrasion was considered comparable to a rubbing action of

the four fingers (scratch or hook) or pressing with the palm of

the hand.

Hand impact was not addressed in this comparison of maximum

forces exerted by hand actions and the capacities of the prototype

test devices. The reason was that, in the limited tests conducted

impact testing was not performed because the necessary precautions

could not be assured to prevent damage or harm to the test subject.

The test protocol is described in Kroemer's report. Two groups

of subjects were used: 21 students and 12 shop personnel. For

all tests, the shop personnel group was found to exert higher

1 average forces than the student group. This was attributed to

the shop personnels' common use of their hands in performing shop

work for some period of time. In this Appendix, the data for the

shop personnel were used for comparison to the capacities of the

prototype devices.

C2
C. 3 Comparison of Hand Actions with Prototype Devices

Table C2 presents a comparison of the maximum hand forces exerted

by the shop personnel group, for the five selected hand actions

(Section C.2), and the capacities of the prototype devices. In

developing the prototype devices, it was intended to have their

capacities comparable to the maximum forces generated by hand

actions considered similar to the mechanical actions of the

devices. It is evident from Table C2 that, for most tests, the

maximum force of a given hand action was greater than the

capacity of the associated prototype device. Only in the case of

the surface compression/shear test was the maximum force of the

tip pinch hand action less than the capacity of the device. For

purposes of this study, the differences between the maximum

forces generated by the hand actions and the capacities of the

devices were considered acceptable. The forces which could be

applied by the prototype devices were within the range of forces

generated by the selected hand actions, and in most cases,

comparable to the maximum forces of the hand actions. In

conducting the laboratory tests to evaluate the prototype

devices, many tests were performed at force levels less than the

capacities of the devices.

As mentioned in Appendix B, the maximum force produced by the

compression/ shear devices was derived from a simple calculation

based on the average distance from the center of the torque

screwdriver shaft to the center of the fins which indicated that

C3
the average force per fin was about 0.5 lbf (2 N) per 1 lbf* in.

(0.1 N*m) increment of torque. On this basis, because the

maximum value of torque generated by the screwdriver was

30 lbf ‘in. (3.4 N*m), the capacity of the compression/shear

device was estimated as about 15 lbf (67 N) per fin.

C4
able Cl. Description of Hand Actions Compared to Prototype Devices

and Description

ction

'ip

inch

ad

inch

'oke

cratch

r Hook

aim

ress

Force Between Opposing Tips

Posture: the thumb tip opposes the tip of each finger

Transmitting surface: opposing tips of digits

Direction of force: through centers of opposing surfaces

Digits: 1 opposing 2; 1 opposing 3; 1 opposing 4; and

1 opposing 5

Force Between Opposing Pads

Posture: the thumb pad opposes the pad of each finger

Transmitting surface: opposing pads of fingers

Direction of force: through centers of opposing surfaces

Digits: 1 opposing 2; 1 opposing 3; 1 opposing 4;

1 opposing 5; and 1 opposing 2 & 3 combined

Tip Force. Straight Digit

Posture: arm, hand, and digit are fully extended,

horizontal, and unsupported. Palm is about

horizontal. Thumb is abducted.

Transmitting surface: tip of the digit

Direction of force: in line with the extended digit

Digits: thumb, index, middle, ring, and little

Pad Force, Bent Digit

Posture: The included angle between the distal and

proximal phalanges of the tested digit is

approximately 90°. For digit 1, the

metacarpal portion is abducted at the

discretion of the subject.

Transmitting surface: pad of the digit

Direction of force: parallel to the proximal phalanx

of the tested digit

Digits: thumb, index, middle, ring, and little

Palm Force

Posture: arm, hand, and fingers are fully extended,

horizontal, and unsupported.

Transmitting surface: palm of the hand

Direction of force: perpendicular to the palm

C5
Table C2 . Comparison of Maximum Hand Action Forces With the Capaciti

of the Prototype Test Devices3

Test Friability Hand

Level

Action*3 Hand

Force

Action

, max. c

Capacity

Test Devi

lbf N lbf N

Surface

Compression/

Shear

High/

Moderate

Tip Pinchd 14

(4)

63

(16)

15 67

Bulk

Compression/

Shear

High/

Moderate

Pad Pinche 21

(4)

95

(19)

15 67

Indentation^ Moderate Poke-f inger9 19

(6)

86

(28)

18 80

Poke-thumb 31

(9)

138

(41)

18 80

Abrasion^ Moderate/

Low

Scratch or

Hook (with

4 fingers)

57

(14)

252

(63)

18 80

Palm Press 52

(15)

233

(65)

18 80

a. In conducting the laboratory tests, many were performed at force

levels less than the capacity of the devices.

b. A description of the hand actions are given in Table Cl.

c. Data are taken from Kroemer's report. Numbers in parentheses are

standard deviations for the average maximum forces.

d. The data are for pinching with the tips of the thumb and the midd]

finger, which was the strongest of the measured tip pinch actions.

e. The data are for pinching with the pad of the thumb and the pads c the index and middle fingers, which was the strongest of the measi

pad pinch actions.

f. The force is the normal or bearing force applied during testing.

g. The data are for poking with the middle finger, which was the

strongest of the measured finger poke actions.
iBS«l 14A (REV. 2-80

U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publ ication Date

BIBLIOGRAPHIC DATA

SHEET (See instructions)

REPORT NO.

NISTIR 88-3848 November 1988

4. TITLE AND SUBTITLE

Friability of Spray-Applied Fireproofing and Thermal Insulations: Laboratory

Evaluation of the Prototype Test Devices

5. AUTHOR(S)

Walter J. Rossiter, Jr., Willard E. Roberts, Robert G. Mathey

5. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, State, ZIP)

General Services Administration

Safety and Environmental Management Division

Washington, DC 20405

0.

SUPPLEMENTARY NOTES

~j Document describes a computer program; SF-185, FlPS Software Summary, is attached.

1.

ABSTRACT (A 200-word or less factual summary of most si gnificant information. If document includes a significant

bi bl i o graph y nr I irerature survev mentinn it h prp)

This report describes the results of the second phase of a study to develop a field test method for assessing the friability of spray-applied fireproofing

and thermal insulating materials. Phase 2 is the laboratory evaluation of the

prototype devices for conducting surface and bulk compressi on/shear

,

indentation, abrasion, and impact tests. These tests were performed on specially prepared fireproofing materials, produced to have a range of

friabilities. Differences in response of the test samples to dislodgment or indentation were observed in the tests.

In the surface and bulk compressi on/shear tests, it was found that, for a given type of material, as the density increased, the torque level at which

dislodging occurred increased. In the indentation tests of the fibrous

materials, the indentation depth increased as their density decreased.

However, little indentation of the cementitious samples occurred regardless of

their density. In tests using the abrasion device, all samples left a residue

over the range of bearing forces examined. The amount of residue, as determined by image analysis, was extremely variable, and did not relate to

the type or density of the material. With regard to the impact tests, all

samples underwent some amount of indentation. The lower density fibrous

materials experienced the greatest depths of indentation.

The results indicated that the surface and bulk compressi on/shear

,

indentation, and impact devices provided some measure of discrimination

between samples subjectively judged as having "high" and "moderate"

friability. In contrast, the abrasion device was non-discriminating in that,

for all tests, a residue was produced. It was concluded that all devices be

included in the field phase of the study using in—place spray-applied

f i reproof i ngs having different levels of friability.

2.

KEY WORDS (Six to twelve entries; alphabetical order; capital! ze only proper names; and separate key words by semicolon s) abrasion; asbestos-containing materials; compression; f i reproof i ng ; friability;

impact; indentation; mechanical tests; shear; spray-applied; test devices; test

methods; thermal insulations

3.

AVAILABILITY

ZX Uni imited

For Official Distribution, Do Not Release to NTIS

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