Research Information Center

National Bureau of Standards

Gaithersburg, Maryland 20899

NBSIR 87-3621

m ntm Udo i Friability of Spray-Applied ml *m

Fireproofing and Thermal

Insulations: The Basis for a Field

Test Method

Walter J. Rossiter, Jr. Willard E. Roberts

Robert G. Mathey

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

December 1987

Prepared for: General Services Administration

Safety and Environmental Management Division

Washington, DC 20405

NBSIR 87-3621

FRIABILITY OF SPRAY-APPLIED

FIREPROOFING AND THERMAL

INSULATIONS: THE BASIS FOR A FIELD

TEST METHOD

Walter J. Rossiter, Jr. Willard E. Roberts

Robert G. Mathey

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

December 1987

Prepared for: General Services Administration

Safety and Environmental Management Division

Washington, DC 20405

U.S. DEPARTMENT OF COMMERCE, C. William Verity, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
'
ABSTRACT

This investigation was Phase 1 of a two part study to develop a

test method that can be used in the field to measure the

friability of spray-applied fireproofing and insulating materials

containing asbestos fibers. The objective of the first phase was

to establish the technical basis for development of a test method

to measure friability quantitatively. The test method is

intended for use in lieu of current field procedures which

involve evaluation by hand pressure and are subjective. A flow

chart was prepared outlining a systematic sequence for conducting

the field assessments. Four test methods were selected:

compression/shear, indentation, abrasion, and impact. For each of

the four tests, mechanical devices were devised by modification

of existing material test apparatus. A description of the test

devices is given in the report. Preliminary laboratory tests,

conducted on specially prepared spray-on (non-asbestos) materials

having a range of friability, were performed. The results

suggested that the devices could distinguish differences in

friability between the test samples. Further evaluation of the

prototype test devices will be made in the laboratory and field

in Phase 2 of the study.

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

fireproofing; friability; impact; indentation;

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

thermal insulations

iii
TABLE OF CONTENTS

Page

ABSTRACT iii

1. INTRODUCTION 1

1 . 1 Background 1

1 . 2 Objective 3

1 . 3 Scope of the Study 4

2. CURRENT METHOD OF ASSESSING FRIABILITY 6

2.1 Definition of Friability 6

2.2 Assessing Friability Using Algorithms 8

3. APPROACH TO DEVELOPING A FIELD TEST FOR FRIABILITY ... 12

3.1 Mechanical Tests Related to Hand Actions 12

3.2 Methodology for Conducting Mechanical Tests. ... 19

4. PROTOTYPE TEST DEVICES FOR FRIABILITY ASSESSMENT .... 22

4.1 Description and Use of the Test Devices 23

4.2 Preliminary Testing 31

5. SUMMARY AND CONCLUSIONS 36

6 . ACKNOWLEDGMENTS 38

7. REFERENCES 39

iv
LIST OF TABLES

Page

Table 1. Summary of Modes for Fiber Release

and Dispersion 40

Table 2. Summary of the EPA Algorithm for Exposure

Assessment, As Published in 1982 41

Table 3. Descriptors of Levels of Friability

from the 1982 EPA Algorithm 42

Table 4. Descriptors of Levels of Friability

from the GSA Algorithm 43

Table 5. Summary of Hand Actions and Related

Mechanical Tests 44

Table 6. Spray-Applied Fireproofing Materials Used

in Preliminary Tests 45

LIST OF FIGURES

Page

Figure 1. Types of Spray-Applied Materials, As Given

in Reference 4 46

Figure 2. Flow Diagram Indicating the Sequence

of Conducting Friability Tests 47

Figure 3 . Prototype Device for Conducting Surface

Compression/Shear Tests 48

Figure 4. Prototype Device for Conducting Bulk

Compression/Shear Tests 49

Figure 5. Prototype Device for Conducting Indentation

Tests 50

Figure 6. Prototype Device for Conducting Abrasion

Tests 51

Figure 7. Prototype Device for Conducting Impact Tests . . 52

v
I . I
1. INTRODUCTION

1 . 1 Background

Between the mid-1930s and the late 1960s, asbestos-containing

materials were widely used in building constructions [1]. The

predominant application was the spraying of fireproofing, and of

thermal and acoustical insulation, on structural members, walls,

and ceilings. Many factors made these materials attractive for

use. For example, in the case of fireproofings, spray-on

asbestos-containing materials were inexpensive, were quick to

install, involved only one building trade, and were easily

integrated within the overall construction process [2].

Most spray-on asbestos-containing materials are considered

friable, in that they may be readily crumbled or pulverized to

release airborne asbestos fibers into the building environment

[1]. The degree of friability of the asbestos-containing

fireproofing and insulation varies between installations. The

variation can be due to the nature or composition of the

material, or its deterioration. Guidelines for selecting

appropriate abatement techniques include consideration of the

friability of the asbestos-containing material.

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

1
asbestos-containing materials were extensively used in building

constructions. At present, GSA owns approximately 2500

buildings. A recent GSA survey indicated that almost 1200 of

them have asbestos-containing material. In some of these

buildings, GSA must assess the condition of the asbestoscontaining material, monitor changes in condition over time, and

recommend appropriate abatement actions.

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

assessments of its buildings that have asbestos-containing

materials [3]. The GSA algorithm was developed on the basis of

modifications and additions to an earlier EPA algorithm [4]. The

GSA assessment procedure is intended to ’’provide a relative index

that indicates an overall risk potential" [3]. The use of the

algorithm allows GSA to estimate which buildings potentially have

the most severe problems. It also allows GSA to rank the results

of the condition assessments in a priority order for those

buildings needing abatement actions.

The GSA algorithm assesses the friability of the asbestoscontaining material from a subjective and non-defined test using

the hand ( see Chapter 2 ) . 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

2
National Bureau of Standards (NBS) to develop a field test

procedure for assessing and monitoring the friability of sprayapplied asbestos-containing materials.

This report describes the first 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 . 2 Objective

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. The

study is divided into two phases. The objective of Phase 1 is to

establish the technical basis for development of the test

method. In Phase 2, the test method will be developed. As

indicated, this report presents a summary of the first phase.

3
1 . 3 Scope of the Study

The scope of Phase 1 was limited to research activities

associated with the development of the technical bases for the

field test method for assessing friability. Any determination

that the in-place materials contain asbestos was beyond the study

scope. Confirmation that asbestos is or is not present in

existing spray-applied fireproofing and insulation is another

factor considered in procedures concerning condition assessment.

No testing for the presence of asbestos was conducted during the

study.

The activities performed in Phase 1 of the study included:

o A review of appropriate test methods, which have been used

or have potential for use, for determining the friability of

spray-applied fireproofing and insulation materials.

Sources of information included the archival literature,

reports from Federal and foreign government agencies,

standards organizations, and individuals having knowledge in

friability testing of insulations or condition assessment of

asbestos-containing materials. Included was a review of

past activities carried out by ASTM Committee E06 regarding

friability of spray-on fireproofings [5].

o A review of current subjective techniques for assessing the

friability of spray-applied asbestos-containing materials in

the field. This included discussions with individuals

responsible for conducting field condition assessments.

4
o Field inspections of spray-applied asbestos-containing

materials

.

o The development of a conceptual model for determining the

level of friability in order to assist in proposing suitable

mechanical tests. The conceptual model was developed based

on consideration of hand actions (possibly used by field

inspectors in friability determinations) and the current

descriptors of levels of friability of spray-applied

asbestos-containing material.

o The development of prototype test devices for conducting

friability tests in the field. Preliminary laboratory

evaluation of the devices using specially prepared spray-on

fireproofings which did not contain asbestos was performed.

5
2. CURRENT METHOD OF ASSESSING FRIABILITY

2 . 1 Definition of Friability

As indicated in the Code of Federal Regulations (40 CFR 61,

Subpart M) , a friable asbestos-containing material "means any

material containing more than 1 percent asbestos by weight that

hand pressure can crumble, pulverize, or reduce to powder when

dry" [6]. This definition contains two major factors that impact

on asbestos abatement measures, namely, asbestos content and

ability to release asbestos fibers through crumbling by hand

pressure. Algorithm procedures for assessing the condition of

sprayed-applied asbestos-containing materials were developed by

the Environmental Protection Agency (EPA) to provide a method for

predicting the potential for fiber release and subsequent

contamination of the building space [4].

The key descriptor considered to relate to the potential for

fiber release is the "friable" nature of the asbestos-containing

material. A dictionary definition of the word, "friable," states

that it is an adjective indicating "easily crumbled, pulverized,

or reduced to powder" [7]. This definition is comparable to that

given in the Code of Federal Regulations (CFR) except that the

CFR indicates that the material is dry and the stimulus for

crumbling is hand pressure. From the point of view of risk

management, it is considered that if the material is not friable,

then it cannot be readily crumbled, pulverized, or powdered to

release fibers into the building space. Conversely, friable

6
materials are more likely than non-friable materials to release

fibers when disturbed or damaged [1,8]. The Federal Construction

Council, Consulting Committee on Asbestos, has stated that, in

all cases where friable materials are present, the hazard posed

may not justify immediate corrective action, and that, for each

case, a hazard assessment must be made [1].

The concept of friability of spray-applied asbestos containing

materials is associated with the ability of the fireproofing or

thermal insulation to release particles which may become airborne

and be inhaled. From this point of view, it has been suggested

that characterization of these materials could be carried out by

assessing ease of materials release rather than ease of crumbling

[ 9 ]

.

Some initial work has been conducted on the ease of

materials release (referred to as "releasibility rating”), but no

procedure for field condition assessment has been developed [9].

The EPA has reviewed means of fiber release from the spray-on

materials [4]. Three major modes for release and dispersion of

fibers into buildings were identified:

1. Fallout -- Constant release of fibers which occurs as a

result of weak bonds in the material as it was installed or

which have developed over time due to the deterioration of

the bonding materials.

2. Impact -- Any direct contact with the material that knocks

fibers loose.

7
3. Resuspension -- Secondary dispersal or reentrainment of

fibers which have previously been released by fallout or

impact

.

A summary of the EPA review of the three modes of fiber release

and dispersion is given in Table 1. As is evident, many factors

could affect the release of fibers and their resuspension. 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. For example, an approach for future

investigation might be based on consideration of the energy

involved in fracturing or deforming the material.

2 . 2 Assessing Friability Using Algorithms

Algorithms were developed by EPA to provide a numerical method to

assist in evaluating the potential hazard of exposure to asbestos

fibers released from spray-applied materials and to determine

appropriate corrective actions [4]. Currently used algorithms

( GSA [3] and the Navy [10]) are based on that developed by EPA.

Table 2 presents a summary of the factors that were incorporated

into the EPA algorithm [4].

Since 1985, EPA no longer suggests the use of algorithms for

assessing the potential of fiber release from asbestos-containing

8
materials [8]. The agency has indicated that such use has "met

with mixed success." In particular, in tests conducted for EPA,

the ratings achieved according to the algorithm procedure were

not found to relate to the levels of measured airborne asbestos

[8]. Algorithm methods are intended to consider individual

factors affecting potential for fiber release, whereas air

monitoring is an indicator of fiber level at the time the

measurement is made. EPA has indicated that a simple,

nonnumerical rating system, based on a consideration of the

factors affecting asbestos-release (Table 1) is useful [8]. In

using the nonnumerical rating, EPA has indicated that the

material should be considered friable if, upon rubbing, it

crumbles or produces a light powder residue.

Where algorithms are employed to assess the condition of sprayedapplied asbestos-containing materials, eight factors concerning

material use and its condition are assigned a numerical value.

The eight factors in the algorithm have been selected based on

consideration of modes causing release of the spray-applied

asbestos-containing material (Table 1). The first seven

algorithm factors (material condition, water damage, exposed

surface area, accessibility, activity, air plenums, and

friability) are evaluated in the field by the inspector. The

eighth factor (asbestos content) is determined from a laboratory

test on samples removed from the installation. In using the

algorithm to obtain a numerical indication of the potential for

9
asbestos exposure, the sum of the numerical ratings for the first

six factors (Table 2) is taken. That sum is, in turn, multiplied

by the ratings obtained for factors 7 (friability) and 8

(asbestos content). Thus, if the material contains no asbestos

or is assessed not to be friable, the algorithm yields a

numerical value for potential of fiber release of zero.

The fact that the numerical rating factor for friability is used

as a multiplier in the algorithm emphasizes the importance of

evaluating this property in a satisfactory manner. The current

directives given to field inspectors for assessing friability

indicate that they are to use their hands in providing the

numerical value for the algorithm. For example, in the original

EPA inspection manual outlining its algorithm, it was stated [4]

that ”in order to evaluate the friability of the material, it

must be touched."

Figure 1 is a copy of an EPA summary of the types of sprayapplied asbestos materials in place in existing constructions

[4]. The summary was prepared by EPA based on extensive field

surveys. It is evident from Figure 1 that different types of

spray-on asbestos-containing materials have been used in

buildings. It is also evident that these materials have

different physical properties and vary in the level (or degree)

of friability. It is considered that "the more friable the

10
material, the greater the potential for asbestos fiber release

and contamination" [4].

The algorithm developed by EPA considered four levels of

friability. Table 3 lists the descriptors associated with the

four levels of friability as given in the EPA algorithm. Table 4

gives similar descriptors of friability from the GSA algorithm.

These two tables contain comparable descriptors of friability.

This is not unexpected, since, as previously noted, the GSA

algorithm was based on that of EPA [4]. The EPA descriptors are

broader in scope than those of GSA. In particular, the GSA

algorithm does not make reference to non-friable materials. In

developing its algorithm, GSA intended to have a method for

assessing the condition of "surfacing" asbestos-containing

materials. Surfacing materials are those that are sprayed or

troweled on ceilings (or above suspended ceilings), walls, and

structural members [3]. GSA considered, a priori, that in the

cases of the sprayed-on, troweled-on and wet-applied surfacing

materials in its buildings, the materials were considered to have

some degree of friability. Thus, a category of "not friable" was

not included in the GSA algorithm.

11
3. APPROACH TO DEVELOPING A FIELD TEST FOR FRIABILITY

3 . 1 Mechanical Tests Related to Hand Actions

The rationale behind the assessment of the friability of the

asbestos-containing material is to have an indicator of the

potential for release of asbestos fibers into the building

environment. Abatement actions taken to minimize risk of

exposure consider that, as the friability of the material

increases, the potential for fiber release and contamination

increases

.

The use of the hand to estimate the level of friability is only a

comparative indicator of the ease of dislodging, or material

release to cause fibers to be airborne. In assessing friability

using the hand, the forces involved in dislodging the material

can be no greater than those obtainable by the hand, and thus,

presumably, relatively low. This is consistent with the

dictionary definition of "friable" as being easy to crumble or

pulverize. Obviously, a major limitation in using the hand is

that it is a subjective test. Hand strengths vary between

individuals, and thus it is possible that various inspectors can

assign different levels of friability to the same in-place

material

.

A field test for friability must be practicable in that the

equipment should be relatively easy to transport, set up, and

use. The cost of conducting the tests must also be relatively

12
low. For example, the assessment of the condition of sprayapplied asbestos-containing materials in a large multi-story

building may involve hundreds of measurements. Techniques that

would be time-consuming for each measurement are far less

desirable than short, quick procedures as candidates for test

method development.

The approach taken in the study to develop a field test for

friability is to provide mechanical tests related to the hand

actions possibly used by field inspectors. The selected test

procedures are chosen with consideration of the levels of

friability and the friability descriptors outlined in the

algorithms coupled with the degree of typical force which

the human hand can exert in various actions used by field

inspectors. Such an approach is considered a positive step in

quantifying the procedure used in the building industry since the

late 1970s for condition assessment. In particular, the approach

taken is consistent with that presently used in the field by GSA

for providing rankings of the priority of needed abatement

options for GSA buildings.

In relating the test procedure to directives given in algorithms,

it was decided to use the friability descriptors given in the

EPA-developed algorithm (Table 2). The EPA algorithm considered

all types of spray-on materials, and was not limited to materials

assumed, a priori, to have some degree of friability, as was the

13
case for the GSA-developed algorithm. In taking this approach,

the field test procedure developed in the present study would be

applicable to both types of spray-applied materials (i.e.,

fibrous and granular cementitious) and all levels of friability.

The four levels of friability generally considered in algorithms

are: not friable, low friability, moderate friability, and high

friability (Table 3). It is evident from Table 3 that the

current methods for friability assessment depend upon using the

hand in some manner such as impact, rubbing, indenting, and other

ways that are not quantitatively defined (e.g., minimal hand

pressure)

.

In developing a field friability test procedure of mechanical

tests related to hand actions possibly employed by field

inspectors, two key factors need to be addressed:

1) The relationship between the descriptors of the four levels

of friability and specific hand actions used at each level

should be set forth in a logical manner. This would provide

background as to which mechanical tests could be focused on

in the laboratory work. Although all background information

needed to decide which mechanical tests to conduct may not

be available, at least the selection of the candidate tests

would be based on hand actions that are consistent with

present methods for friability assessment. As an example of

the type of information which is not available regarding

14
test method selection, it has been found through discussions

with individuals conducting field assessments that most all

hand actions may be used in the field in attempts to

dislodge asbestos-containing materials from a substrate.

However, the frequency of the various possible types of hand

action used is not available.

2) The maximum forces which the hand can impart for each type

of mechanical action used to assess friability should be

considered in order to set limits of force in the mechanical

tests. A review of the literature regarding forces

associated with hand actions indicates that data on the

subject are limited. NBS obtained the assistance of

Prof. 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 asbestos-containing

materials. The results of his study will be presented in

the final report of this investigation.

The paragraphs which follow provide an outline describing the

relation of the levels of friability to hand actions (and thus

mechanical tests). Based on the discussion in these paragraphs,

a flow diagram for conducting field tests of friability was

developed and candidate mechanical tests were selected.

15
3.1.1 Materials in the Category of "Not Friable"

Materials in this category "cannot be damaged by hand," and thus,

would be expected to be "concrete like" (Figure 1). The

description of friability levels (Table 3) provides no

information as to what hand actions a field inspector would use

to determine that the material cannot be damaged by hand. It is

assumed that one forceful hand action would be an impact motion

such as punching. Another might be a concentrated scratching

motion with the tip of a nail. In the case of punching, if such

action would not damage the spray-on asbestos-containing material

at a force comparable to the maximum that could be imparted

without damage to the hand, then the material could be considered

"not friable." This suggests that an impact test should be used

as a candidate for this level of friability.

3.1.2 Materials in the Category of "Low Friability"

Materials in this category "are difficult yet possible to damage

by hand." Materials included here might be expected to approach

"concrete like," or be "granular cementitious" (Figure 1). The

descriptor of friability levels (Table 3) specifically indicates

that two hand actions are involved here. First, "the material

can be indented by forceful impact." Thus, to determine this

level, an impact test is required. It is assumed that the same

impact test pertaining to the non-friable materials could be used

to measure low friability.

16
Second, the descriptor for low friability also states that "if

the granular, cementitious asbestos-containing material is

rubbed, it leaves granules on the hand..." The rubbing action by

the field inspector is taken to be an abrasion motion. Thus, an

abrasion test is also assumed as a need to determine that a

material is characterized as having low friability.

3.1.3 Materials in the Category of "Moderate Friability"

Materials in this category are "fairly easy to dislodge and crush

or pulverize, and may be removed in small or large pieces."

Materials included here might be both "granular cementitious and

fibrous" (Figure 1). Although fibrous materials are generally

considered to be in the category of high friability, it should

not be ruled out, a priori, that some fibrous materials would

fall in the moderate friability level. For moderate friability,

the level descriptor (Table 3) specifically mentions rubbing and

indentation. In the former case, an abrasion test would be

required, whereas in the latter case, an indentation test would

be needed.

However, in addition to the hand actions specifically denoted, it

is envisioned that many other actions might be used to "remove

small or large pieces" of asbestos-containing material from its

substrate. These actions may be imagined to include pinching,

squeezing, scratching, clawing, pushing, and pulling on the

surface, particularly where the material surface is non-uniform

17
and contains irregularities which could provide a location for

gripping. Thus, the mechanical tests having possible

applicability to the level of moderate friability include

compression (pinching, squeezing), shear (pushing), tension

(pull), and a combination of indentation/tension/shear (poking,

clawing, scratching actions).

3.1.4 Materials in the Category of "High Friability"

Materials in this level are "easily crushed or pulverized by

minimal hand pressure and they may disintegrate or fall apart

when touched." Materials included here would be generally

expected to be "fibrous" (Figure 1). The descriptor of

friability levels (Table 3) makes no reference to any specific

hand actions. It is assumed that, in general, any hand action

that dislodges the material in practice could be used. It is,

thus, considered that any of the hand actions given in the

sections above could also be used as an indicator of high

friability. Potential mechanical tests could then include

compression, tension, and shear. Whatever the test selected, the

amount of pressure exerted in the test should be low, in keeping

with the directive that the material is damaged by "minimal hand

pressure." Selection of the same appropriate mechanical test

procedure here, as for the category of "moderate friability,"

would provide a means for distinguishing between the two levels,

provided that the tests were conducted at different pressure

levels

.

18
3 . 2 Methodology for Conducting Mechanical Tests

The foregoing discussion indicates that a number of mechanical

tests related to hand actions may possibly be used in the field,

depending upon the level of friability of the spray-on material.

Table 5 is a summary of some hand actions and possible mechanical

tests that are considered to relate to the different levels of

friability. This table indicates that, for the moderate and high

friability levels, there is an overlap of the types of mechanical

tests. Thus, the same tests may potentially be used for each

category, but the pressure levels would have to vary.

For a given level of friability (notably, high and moderate),

there is no need to conduct all mechanical tests suggested by the

implied hand action. It is only necessary to have a suitable

test that is consistent with field practice, and demonstrate that

the material is, or is not, resistant to the pressure exerted in

the test. Resistance in this case means that material cannot be

dislodged or released from its substrate, or indented, under the

given test conditions.

19
Based on Table 5, the following

preliminary testing:

Friability Level

High

Moderate

Low

Not Friable

test procedures were selected for

Mechanical Test

Compression/Shear

Compression/ Shear

Indentation

Abrasion

Abrasion

Impact

Impact

Figure 2 is a flow diagram of the suggested sequence for

conducting the field tests. The device selected for the

compression/shear tests was based on modification of a torque

screwdriver, which is why torque is mentioned in the flow

diagram. All devices for conducting these tests referred to in

Figure 2 are described in Chapter 4 of this report. In using the

flow diagram for conducting field assessments of asbestoscontaining materials, tests should be conducted in turn until a

positive result is obtained (e.g., material is dislodged from

spray-on fireproofing or insulation) , or until the final

test (impact) indicates that the sample is not friable. In the

case of friable materials, the level of friability is denoted by

the location in the flow diagram at which the result of the test

is positive. Proper safety precautions will need to be followed

when the field tests are conducted.

20
In Figure 2, note that different test methods result in placing

the material in the same friability category. For example,

compression/shear, indentation, and abrasion tests may all

categorize a material as moderately friable. For purposes of the

present study, there is no intent to imply that different

subcategories of friability exist in these cases. This is

consistent with the different descriptors for a given level of

friability (Table 3).

It is evident from Figure 2 that the first four tests (two

concerning high friability, and two for moderate friability)

involve compression/shear tests conducted on the surface and bulk

of the samples. The use of compression/shear tests for both bulk

and surface properties was suggested based on initial testing of

non-asbestos containing spray-on materials in the NBS

laboratories. It was found that the surface compression/shear

characteristics and bulk compression/shear characteristics of

individual specimens could be different under similar test

procedures and warrant separate examination. In particular, for

the laboratory specimens, the surface was more susceptible to

crumbling than the bulk of the material. Since the surface of

in-place materials could be the most likely source of fiber

release, the surface compression/shear tests should be conducted

first.

21
4. PROTOTYPE TEST DEVICES FOR FRIABILITY ASSESSMENT

This section of the report describes the prototype mechanical

test devices developed for assessing the friability of sprayapplied asbestos-containing materials in a manner consistent with

that used by inspectors in the field. The four tests were

considered for use with the flow chart given in Figure 2: (1) a

compression/ shear test (surface and bulk), (2) an indentation

test, (3) an abrasion test, and (4) an impact test. As is

evident from Figure 2, the asbestos-containing material is

categorized into one of the four levels of friability according

to the results of the tests.

In developing the prototype test devices, some criteria dealing

with practicality were kept in mind. The devices had to be easy

to transport and use by one person, and thus, relatively light in

weight and compact. It was considered that they should not

require electrical power for operation, but be capable of being

manually operated. Where possible, they should use readily

available test equipment in their production, and preferably with

only minor modification. In addition, the devices should be

readily calibrated during production. Each device should also

have a built-in mechanism to limit the pressure applied. In this

way, the operator may only apply the load intended in the test

procedure.

22
4 . 1 Description and Use of the Test Devices

4.1.1. Compression/Shear Test Device. Two compression/shear

measurements are made on a specimen, one involving the surface

and the other concerning the bulk (Figure 2). Both use a

commercially available torque screwdriver as the basis of the

test device. The screwdriver was a model TS-30, manufactured by

the Utica Tool Co. Inc.^ Torque screwdrivers are designed such

that, when torque is applied to the handle at a value below a 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

freely without rotation of the driver shaft. This limits the

amount of torque that may be applied to a screw or other object

used with this type of screwdriver. The torque screwdriver used

for the prototype compression/shear test device 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).

In proposing the test for the compression/shear properties of a

specimen, a disc with fins on its face was attached to the torque

screwdriver. The disc can be pressed down on the test material

so that the fins may penetrate it. Dislodgment of the material

1. Certain trade names or company products are mentioned in

the text here and in subsequent chapters 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.

23
may occur upon rotation of the screwdriver, depending upon the

torque level at which it was set. If the torque level was set

low, then free rotation of the screwdriver handle would occur and

no dislodgment of the asbestos-containing material would take

place. For the attachment of the disc 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.

In performing the preliminary tests, the difference between

conducting a surface compression/shear test and a bulk

compression/shear test was in the size of the disc and the

configuration of the disc fins. Figure 3 is a photograph of the

torque screwdriver and attached disc for surface compression/shear

testing. The disc for surface compression/shear was machined

from aluminum. It was 3 in. (75 mm) in diameter and 0.5 in. (13

mm) thick with six 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

top surface to a dull knife edge (45° bevel). The reverse side

of the top surface of the fins was normal to the disc when it was

turned in a clockwise rotation. The six fins were spaced 60

degrees apart and 1/2 in. (13 mm) from the outer edge of the

disc

.

24
A photograph of the torque screwdriver and disc for bulk

compression/shear testing is given in Figure 4. The disc used

for conducting bulk compression/shear testing was machined from

brass. It was 2 1/4 in. (57 mm) in diameter and 1/4 in. (6 mm)

thick with four fins on the face side. The fins were 1/2 in. (13

mm) high, 3/4 in. (19 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 top

surfaces. For this disc, the four fins were set 90 degrees apart

and set flush with the outer edge of the disc.

In using the compression/shear test device, a torque level, at

which free rotation of the screwdriver handle would occur, was

selected. The disc (either for surface or bulk

compression/shear) was set flush on the surface of the test

specimen, with the fins of the disc penetrating the specimen.

The screwdriver handle was manually turned such that either

material was dislodged from the test specimen or free rotation of

the driver handle took place.

4.1.2. Indentation Test Device. The indentation test device was

developed through modification of a commercially available

"pocket" penetrometer. Such tools are used for soil testing.

The indentation test device is shown in Figure 5. The

penetrometer modified in the study was model H-4200, manufactured

by the Humboldt Mfg. Co. It had a scale calibrated in kg/cm2 .

25
The unmodified penetrometer consisted of a 5/8 in. (16 mm) hexshaped aluminum housing tube with a 1/4 in. (6 mm) penetration

rod protruding from one end. This rod is attached to a

calibrated spring housed in the aluminum tube. The end of the

tube opposite the penetration rod contains an indicator rod with

graduation marks every 0.25 kg/cm^ of load. To use the

penetrometer, the penetration rod is placed on the test surface

and a load is applied. When resistance to penetration is met,

the penetration rod retracts into the housing tube and the spring

is loaded in compression. The indicator rod is pushed out of the

housing as the penetration rod retracts, providing a measure of

the penetration resistance of the test surface.

In the present study, modification of the end of the penetration

rod of the commercially-available penetrometer was done to

distribute the penetration load over a larger surface area and to

provide control of the applied penetration force. In this

regard, a foot, 3/4 in. (19 mm) in diameter and 1/2 in.

(13 mm) thick was attached to the end of the penetration rod

(Figure 5). The size of this foot was selected to be comparable

to that of the tip of an adult male index finger. A collar, 3

in. (75 mm) in diameter, was mounted around the penetration rod.

The collar was secured to the housing of the penetrometer using a

set screw which allowed its repositioning at various positions

along the housing. The face of the collar was perpendicular to

the penetration rod to provide constant angle of loading to the

26
test surface. Contact of the collar on the specimen surface

provided a stop to allow loading to a predetermined level during

indentation testing and also to control overloading during

testing.

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

penetrometer was placed on the surface of the test specimen.

Then, a load was manually applied to the device until the collar

was flush with the test specimen surface. In this way, the foot

of the penetration rod either indented the test specimen or the

rod retracted into the housing, causing the indicator rod to

extend. The amount of extension of the indicator rod was an

indication of the amount of retraction of the penetration rod (or

lack of indentation into the test specimen). For example, if the

indicator rod extended fully, then indentation of the test

specimen did not occur.

The maximum load 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 housing

resulted in different test loads.

4.1.4. Abrasion Test Device. The abrasion test device was also

developed with modification of the H-4200 "pocket" penetrometer.

The concept for the abrasion test device was based on the chalk

test apparatus described in ASTM Standard D 659 for "Evaluating

27
the Degree of Chalking of Exterior Paints" [11]. In conducting

this ASTM test, a piece of black felt fabric is rubbed, using a

prescribed procedure, on the painted surface, and the felt is

visually examined for the amount of powdered residue ("chalk")

that is retained on its surface.

Figure 6 shows a photograph of the abrasion test device. It can

be seen that a collar has been mounted around the penetrometer

housing. For this device, the collar was 5 in. (125 mm) in

diameter. The position of the collar on the housing was

adjustable in order to control the amount of applied load. A

foot, 1 1/2 in. (38 mm) in diameter and 5/8 in. (16 mm) thick,

was attached to the penetration rod of the penetrometer. A guide

rod was extended from the rear face of the foot through the

collar to prevent rotation of the foot and penetration rod during

abrasion testing. This was necessary since the penetration rod

of the unmodified penetrometer was free to rotate. The rotation

had to be eliminated to use the tool as an abrasion device.

The front face of the foot was planar and perpendicular to the

penetration rod. Black felt was attached to the foot using "hook

and loop fasteners" (commonly called Velcro). One piece of

Velcro, which was available with a self-stick adhesive backing,

was adhered to the front face of the foot. Another piece of

Velcro was adhered in the same manner to a 1 1/2 in. (38

mm) diameter disc of black felt. When the two pieces of Velcro

28
were connected together, the felt was attached satisfactorily to

the abrasion test device to remain securely in place during

abrasion testing. By using the Velcro to attach the felt to the

test device, the felt disc could be replaced, as needed, for each

test

.

In conducting the abrasion test, the felt-faced foot of the

device was set on the surface of the specimen. Load was applied

until the collar was flush with the surface of the test

specimen. At that point, the device was manually rotated 90

degrees. The felt was visually examined for the presence of a

powdered or granular residue. For each subsequent test, the felt

was removed from the foot of the device and a new piece was

attached.

4.1.4. Impact Test Device. The prototype test device for impact

was based on a commercially available rebound hammer that has had

extensive field use for testing the hardness of in-place

concrete. For this study, the hammer was modified to allow the

addition of removable tips of varying size and hardness to the

hammer head in order to vary the impact characteristics.

Figure 7 shows a photograph of the impact device. The unmodified

commercially available hammer was manufactured by Tecnotest.

This hammer is a plunger type with a spring loading mechanism.

The spring is loaded by placing the head of the hammer on the

29
surface to be tested, and applying a force by pushing on the base

of the hammer. As force is applied, the plunger retracts into

the hammer body and the spring contracts until a predetermined

force level is reached. At this point, the spring is released

imparting an impact energy of 1.6 lbf*ft (2.2 N-m). The

modification of the hammer head involved the addition of a metal

plug (by welding) into which screw threads were tapped. In this

way, removable plastic and rubber tips could be used on the

hammer. The tips selected for study were those used with a

standard aluminum mallet that has removable screw-mounted tips.

To date, the tips used with the modified rebound hammer in the

friability test program have been made of soft rubber, chosen to

have a hardness akin to that of the outside edge of the hand.

Two tips were used in the initial testing. One tip had a Shore

durometer hardness, type 2A, of 65 and was 1 1/2 in. (38 mm) in

diameter. The second tip had a Shore hardness, type 2A, of 73

and was 1 in. (25 mm) in diameter. The hardness of the rubber

tips should be periodically checked to determine that it does not

change over time.

To use the impact test device, the tip of the modified hammer was

placed on the surface of the test specimen. The hammer was

manually loaded by pushing on the it until impact occurred. The

specimen was examined visually to determine whether indentation

occurred.

30
It is difficult to relate the use of the impact hammer to the

impact levels associated with hand punching, since no data on the

values of hand impact energies relevant to this study were found

in the literature. Research may be needed to obtain such data.

However, such an investigation was considered complex and beyond

the scope of the present study, particularly in view of the

necessary precautions that needed to be exercised if human

subjects were used to obtain the needed data. As a first step in

relating the use of the impact hammer to the impact levels

associated with hand punching, an empirical test was conducted on

gypsum (drywall) board. In this test, the drywall was supported

on the edges using nominal 2x4 studs and the impact was exerted

away from the board edges. It was found that the impact hammer,

with either of the described tips attached, would damage 1/2

in. (13 mm) drywall, when used on the front surface of the board.

The damage was considered minor, in that slight indentation or

cracking of the drywall was observed at the point of impact. It

was assumed that this impact was comparable to "forceful impact"

(Table 3) using the hand, since experience has shown that drywall

may be damaged by hand punching.

4 . 2 Preliminary Testing

Preliminary testing was conducted using the prototype devices and

laboratory test samples of spray-applied fireproofing. The

results of the preliminary tests are given in this section of the

report. The results suggested that use of the prototype test

31
devices was capable of distinguishing different levels of

friability of the test materials. Extensive evaluation of the

devices was beyond the scope of the first phase of the study, and

will be conducted in Phase 2. Included in Phase 2 will be an

evaluation of the precision of the test devices as determined

through laboratory testing.

4.2.1 Test Materials. Both mineral fibrous and cementitious

spray-applied fireproofing materials (Table 6) were obtained for

preliminary evaluation of the test devices. These materials were

specially prepared to simulate the range of friability levels

given in the algorithms for the condition assessment of asbestoscontaining materials. The average densities of the test materials,

as provided by the material suppliers, are given in Table 6.

Measurements of the density indicated that individual specimens

were within 15 percent of the reported average density, except

for sample No. FI which was within 25 percent. The nominal

average thickness of both the mineral fibrous and cementitious

samples was 1 in. (25 mm) . 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. Both

types of samples were placed on a rigid laboratory bench during

preliminary testing.

These spray-applied samples were examined manually according to

the directives for judging the friability of asbestos-containing

32
materials (Table 3). As judged subjectively, it appeared that,

as the density of a given type of material increased, its

resistance to being dislodged, crumbled, or pulverized using hand

actions increased.

4.2.2 Preliminary Observations with the Compression/Shear Test

Device. The surface compression/shear test was conducted on two

or three locations of the specimens at a number of different

torque levels, as set on the screwdriver. For samples FI, F2,

F3, F4 , and C3, it was found that the torque levels, at which

material was dislodged from the surface of the samples, were 5,

5, 10, 14, and 20 lbf«in. (0.6, 0.6, 1.1, 1.6, and 2.3 N-m),

respectively. This provided initial evidence that the surface

compression/shear test could distinguish between the samples

available

.

Similar results were observed when the compression/shear test was

conducted on the bulk of the samples . For samples FI , F2 , F3

,

and F4 , dislodging of material occurred at 10, 10, 14, and 16

lbf*in. (1.1, 1.1, 1.6, and 1.8 N»m), respectively. It is noted

that the fins did not totally penetrate into the bulk of sample

F4. Also, little penetration of the fins on the disc of the

screwdriver occurred with the cementitious samples. Thus, no

torque value for dislodging the cementitious material was

obtained.

33
4.2.3 Preliminary Observations with the Indentation Device.

The results of the preliminary testing using the indentation test

device indicated that varying behavior of the different samples

could be observed. For the mineral fibrous materials, the

indentation resistance of the material increased with an increase

in density. The preliminary test was conducted at a load of 7.7

lbf (3.5 kgf )

.

The extent of indentation was estimated in units

of depth. For samples FI, F2, F3, F4, and C3, the indentation

was 2.1, 1.7, 0.9, 0.6, and 0.2 units, respectively.

4.2.4 Preliminary Observations with the Abrasion Test Device.

Preliminary testing using the abrasion test device was conducted

only on the cementitious materials, because the descriptors for

friability (Table 3) made reference to rubbing actions only with

cementitious materials. In conducting preliminary abrasion

tests, the collar on the abrasion test device was set so that the

load applied to the surface of the sample was 4.4 lbf (2 kgf).

Although, in the preliminary tests, the abrasion test was only

applied to the cementitious materials, it is considered

applicable to all types of materials. The test may be akin to

rubbing the material to determine whether a residue is produced.

The results using the device were comparable to those using the

hand. When rubbed with the fingers, the three cementitious

samples left a residue on them. The device also gave residues on

34
the black felt for all three cementitious samples. No difference

in the amount of residue on the felts could be visually

distinguished for each of the samples. Further analysis of the

amount of residue was not made during Phase 1, but will be

conducted during Phase 2

.

4.2.5 Preliminary Observations with the Impact Test Device.

All laboratory samples (Table 6) could be indented using the

hand. Thus, it was expected that all samples would undergo some

degree of indentation using the impact test device. This was

found to be the case. The low density fibrous materials (FI and

F2 ) were found to have the greatest extent of indentation.

Quantification of the extent of impact indentation will be done

in Phase 2 of the study.

The impact test device was applied to vinyl asbestos floor tile.

These tiles are normally considered to be non-friable [10]. It

was visually observed that the impact hammer did not indent the

tiles

.

35
5. SUMMARY AND CONCLUSIONS

This investigation was Phase 1 of a study to develop a test

method that can be used in the field to measure the friability of

spray-applied fireproofing and insulating materials containing

asbestos fibers. These materials are considered friable if, when

dry, they can be crumbled, pulverized, or reduced to powder using

hand pressure. The objective of Phase 1 was to establish the

technical basis for development of an objective friability test

method for use in lieu of current field procedures which are

subjective. Currently, inspectors conducting field assessments

must touch the spray-on material with the hand to determine

whether it can be crumbled, powdered, or pulverized. One of four

levels of friability is assigned to a material depending upon the

hand action used and the amount of force applied.

In conducting the study, a review of friability tests that have

been applied or considered to have potential for application to

asbestos-containing materials was made. None of the reviewed

tests was found suitable.

It was proposed to develop mechanical tests for field use. A

flow chart was developed outlining a systematic sequence for

conducting the field assessments. Four test methods were

suggested for development: a compression/shear test, an

indentation test, an abrasion test, and an impact test. The

36
compression/ shear test is intended to be conducted both on the

surface and bulk of the samples.

For each of the four tests, mechanical devices were constructed

with modification of existing construction material test

apparatus. A description of each device is given in the report.

Preliminary laboratory tests, conducted on specially prepared

spray-on materials having a range of friabilities, were

performed. The test materials were mineral fibrous and

cementitious. The results suggested that the devices could

distinguish between degrees of friability of the test samples.

For example, for the fibrous materials, the load required to

damage the samples increased as the sample density increased.

Based on the results of the preliminary testing, it was suggested

that further evaluation of the prototype test devices be made in

Phase 2 of the study. This evaluation will include extensive

laboratory testing including statistical analysis of the results,

and evaluation of the precision of the proposed methods. Field

testing of existing spray-applied asbestos-containing materials

will be conducted. Recommendations will be made concerning

quantitative values for each level of friability used in the GSA

algorithm. The results of Phase 2 will be made available in a

final report.

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, D.G. Bathurst, W. Chan, and

D.F. Sinsel. Appreciation is expressed to the authors'

colleagues at the NBS Center for Building Technology who

contributed to the conduct of the study. H. Fanney, L. Masters,

and G. Frohnsdorff provided many useful comments and suggestions

on a draft of this report. N. Raufaste provided liaison between

GSA and NBS. Special thanks are extended to J. Lechner, NBS

Statistical Engineering Division, for his valuable discussions

and suggestions concerning the development of the test devices.

38
7. REFERENCES

1. "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.

2. Pielert, James H. and Mathey, Robert G. , "Guidelines for

Assessment and Abatement of Asbestos-Containing Materials in

Buildings," NBSIR 83-2688, National Bureau of Standards

(U.S.) (May 1983), 75 pages.

3. "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) .

4. "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.

5. Ellis, W. and Lieff, M.

,

"Asbestos in Buildings -- What

Standards are Needed?", ASTM Standardization News, American

Society for Testing and Materials, Philadelphia, PA (June

1985), pp. 44-47.

6. "Guidance for Controlling Asbestos-Containing Materials in

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

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

7. Webster’s Third New International Dictionary, MerriamWebster Inc., Springfield, MA (1981).

8. "Guidance for Controlling Asbestos-Containing Materials in

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

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

9. "Evaluation of Asbestos Abatement Techniques -- Phase

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

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

10. 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.

11. "Method for Evaluating Degree of Chalking of Exterior

Paints," ASTM D 659, Vol. 06.01, ASTM, Philadelphia, PA

(1987)

.

39
Table 1. Summary of Modes for Fiber Release and Dispersion3

Mode Characteristic FactQrs Affecting Mode

Fallout constant release over

time due to weak bonds;

normally a slow process;

rate may increase with

age

vibration

people movement

cohesive/adhesive strength

application quality

degree of deterioration

environment (humidity, sun)

substrate (smooth vs, rough)

Impact direct contact that knocks

fibers loose; amount of

fibers released can vary

with impact and material

intensity of impact

application quality

cohesive/adhesive strength

degree of deterioration

Resuspension secondary dispersal or

reentrainment of fibers

which have previously been

released by fallout or

impact; amount of fibers

released may depend on the

level of activity

building activities, e.g.:

- foot traffic

- maintenance

- sweeping

- dusting

- air circulation systems

a. This table was summarized from the discussion in Reference [4].

40
Table 2. Summary of the EPA Algorithm for Exposure Assessment3 '*5 Factor Range or Extent Score

1. Material condition None 0

(deterioration/ Moderate, small areas 2

damage) Widespread, severe, pieces dislodged ... 5

2. Water damaged None . . . 0

Minor 1

Moderate to Major 2

3. Exposed surface Not exposed, located above suspended

area ceiling; none visible without removing

panels or ceiling sections 0

10% or less of the material is exposed . . 1

10% to 100% of the material is exposed . . 4

4. Accessibility Not accessible 0

Low, rarely accessible 1

Moderate to high, access may be frequent . 4

5. Activity and None or low, libraries, most classrooms0 . 0

movement Moderate, some classrooms, corridors . . . 1

High, some corridors and cafeterias,

all gymnasiums 2

6. Air plenum or None 0

direct air streams Present 1

7. Friability Not friable 0

Low friability, difficult but possible

to damage by hand 1

Moderate friability, fairly easy to

dislodge and crush 2

Highly friable, fluffy, spongy, flaking,

pieces hanging, falls apart when

touched 3

8. Asbestos content Trace to 1% 0

(total % present) 1% to 50% 2

50% to 100% 3

a. This table was developed by EPA and was taken from Reference 4. It is

noted that EPA no longer uses an algorithm for assessing condition of

asbestos-containing materials [6],

b. In using the algorithm to obtain a numerical indication of the

potential for asbestos exposure, the sum of the numerical ratings for

the first six factors is taken. That sum is, in turn, multiplied by

the ratings obtained for factors 7 and 8.

c. These types of rooms are specifically mentioned, since a prime use of

the EPA algorithm was the condition assessment of schools.

41
Table 3

.

Descriptors of Levels of Friability from the EPA Algorithm,

As Published in 1982 a

Friability Level Descriptor

Not Friable Material that is hard and crusty. Cannot be

damaged by hand. Sharp tools reguired to

penetrate the material.

Low Friability 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.

Moderate Friability 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 asbestos-containing

material leaves a powder residue on the

hands when rubbed.

High Friability 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.

a. This table was taken from Reference 4. It is noted that EPA no

longer uses an algorithm for assessing condition of asbestos

containing materials [8].

42
Table 4. Descriptors of Levels of Friability from the GSA Algorithm3

Friability Level Descriptor

Low Friability Material that could be damaged by hand only

if heavy force is applied. This includes

most troweled materials.

Moderate Friability Fairly easy to dislodge and crush or

pulverize by hand. Material may be removed

in small or large pieces.

High Friability The material is fluffy, spongy, or flaking

and may have pieces hanging down.

a. This table is taken from Reference 3.

43
Table 5. Summary of Hand Actions and Related Mechanical Tests

Level of Hand Action Hand Action Mechanical Test

Friability Specified Implied Associated With

in Algorithm in Algorithm Hand Action

Not None Impact Impact

Friable

Low Impact a Impact

Friability Rubbing Abrasion .

Moderate Indentation — Indentation

Friability Rubbing —

— Abrasion — Pinching/Squeezing Compress ion/ Shear — Pushing Shear

Pulling Tension

Scratching Abrasion

High — Pinching/ Squeezing Compression

Friability —— Pushing Shear

Pulling Tension

Scratching Abrasion

a. No hand actions other than those given in the algorithm descriptors

were considered needed for this level of friability.

44
Table 6. Spray-Applied Fireproofing Materials Used in Preliminary Tests

Average Densitya

Sample

No.

Material Type

lbm/ft^ kg/m^

FI Mineral Fibrous*5 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. Average values to which the materials were manufactured.

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 water

on the job site, forms a slurry for spray application.

45
DESCRIPTION

OF

SPRAY-APPLIED

ASBESTOS-CONTAINING

MATERIAL

• ... = x:

46

Figure

1.

Types

of

Spray-Applied

Materials,

as

given

in

Reference
Surface

Compression/Shear

Tost

LowTorqua

>. >» o = > =

Z O £

• -i a

k. w

U. U.

>. © >*

4* Jr W _

o-Q

-J «

© A

TJ (0 o -

Li. 2 U.

(0 2

©

a

>•

©

** ©

4* (0 h-

<0 O / \ o / \ © •

o / \ I- z / • \ Z / \

h> z / - \

c

o / \ _ / © \ C

o

+4 o

a

a

E \\o§ Ai /

/

\ / »

a

k. Q

\-o

\ c /

©

c

© “ O

< c

47

Figure

2.

Flow

Diagram

Indicating

the

Sequence

of

Conducting

Friability

Tests
Figure 3. Prototype Device for Conducting Surface Compression/

Shear Tests

48
Figure 4. Prototype Device for Conducting Bulk Compression/

Shear Tests

49
Figure 5 Prototype Device for Conducting Indentation Tests

50
Guide Rod Felt

Figure 6. Prototype Device for Conducting Abrasion Tests

51
Tip

Figure 7. Prototype Device for Conducting Impact Tests

52
NBS-114A (REV. 2»8C

)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 87-3621

2. Performing Organ. Report NoJ 3. Publication Date

4. TITLE AND SUBTITLE

Friability of Spray Applied Fireproofing and Thermal Insulations: Basis for a

Field Test Method

5. AUTHOR(S)

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

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

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

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

10.

SUPPLEMENTARY NOTES

i~ ~1 Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

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

bi bliography or literature survey, mention it here)

This investigation was Phase 1 of a two part study to develop a test method that

can be used in the field to measure the friability of spray-applied fireproofing and

insulating materials containing asbestos fibers. The objective of the first phase

was to establish the technical basis for development of a test method to measure

friability quantitatively. The test method is intended for use in lieu of current

field procedures which involve evaluation by hand pressure and are subjective. A

flow chart was prepared outlining a systematic sequence for conducting the field

assessments. Four test methods were selected; empression/shear , indentation,

abrasion, and impact. For each of the four tests, mechanical devices were devised

by modification of existing material test apparatus. A description of the test

devices is given in the report. Preliminary laboratory tests, conducted on

specially prepared spray-on (non-asbestos) materials having a range of friability,

were performed. The results suggested that the devices could distinguish differences

in friability between the test samples. Further evaluation of the prototype test

devices will be made in the laboratory and field in Phase 2 of the study.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

abrasion; asbestos-containing materials; compression; fireproofing; friability;

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

insulations

13.

AVAILABILITY

(3un. imited

| | For Official Distribution. Do Not Release to NTIS

| Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

~i| Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

58

15. Price

$ 13.95

USCOMM'OC 6043-P80
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