-&&r~

NATIONAL BUREAU OF STANDARDS REPORT

Study of the Properties of Rubber Base Calking Materials

(Progress Report No, 2)

by

Arthur Hockman

Report to

the Departments of

the Air Force, the Army, and the Navy

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

6923
THE NATIONAL BUREAU OF STANDARDS

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NATIONAL BUREAU OF STANDARDS REPORT

ms PROJECT

1001-12-10413 August 8, I960

NBS REPORT

6923

Study of the Properties of Rubber Base Calking Materials

(Progress Report No, 2)

by

Arthur Hackman

To

c the Departments of

the Air Force, the Army, and the Navy

IMPORTANT NOTICE

NATIONAL BUREAU OF ST/

Intended for use yvithln the ( to additional evaluation and r< listing of this Report, either li the Office of the Director, Nat however, by the Government ; to reproduce additional copie;

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015.

rogress accounting documents

mally published it is subjected

eproduction, or open-literature

Ion is obtained in writing from

Such permission is not needed,

jrepared if that agency wishes

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

Study of the Properties of Rubber Base Calking Materials

(Progress Report No, 2)

Arthur Hockman

A study of the. properties of polysulfide base joint sealers for use in masonry and other types of construction has been completed.

For this purpose 157 samples were received from 19 manufacturers

„

Standard laboratory test procedures have been developed for six

physical properties; (1) staining effects and color changes, (2)

slumps (3) tack-free time, (4) application life and ease of extrusion,,

(5) hardness,, (6) durability,,

Of 31 samples tested for staining, 25 produced stains on mortar

exposed both in the laboratory at 74 ®F and in the Weatherometer for

500 hr, Intense red stains formed when the sample was protected from

sunlight in the laboratory,, Less intense stains of reddish brown

colors occurred on samples in the Weatherometer or in sunlight. The

stains tended to fade with time, White, gray, neutral, and tan com- pounds darkened to varying degrees after 500 hr in the Weatherometer,

Of 24 non-sag type compounds tested at 122°F in two types of

slump troughs only one slumped excessively, Tao.k- free time tests made

on 22 samples resulted in 3 samples remaining tacky for more than 72

hr.

Application life tests made with the Brookfield Viscometer indicated 41 percent of the 29 samples tested (non-sag type) as compounds

with short application or pot life. Of eight flow type compounds tested,

five also showed short pot life.

Shore "A" hardness values obtained on 100 samples from 17 producers ranged from 10 to 58 at 74 & F with an average of 34, Average

hardness increased by 56 percent when tested at 0

3 F but showed no*

change when tested at 158°F„ There was no residual increase in hardness after the 0°F treatment but after cooling from ISS^F, the residual increase was 24 percent. Seventeen samples exposed in air at 74°F

for 7 to 9 months showed increases in hardness from 0 to 61 percent.

Fourteen samples exposed outdoors for 16 months increased in hardness

from 0 to 147 percent with an average of 31 percent.

The results of durability (bond-ductility) tests made on a total

of 226 specimens with porous accessory materials (concrete, concrete

block, brick and wood) indicated that 52 percent to 60 percent of the

block, brick and wood specimens, and 39 percent of the concrete speci- mens rated "excellent,” Twenty percent of each of the above porous

groups rated "very poor," Similar tests made on 96 specimens with
,

‘
2 ,

non-porous accessory materials (porcelainized steely porcelainized

aluminum, glass, and aluminum) showed 72 percent of the porcelainized

steel specimens as "excellent

,

n and 18 percent "very poor," On the

other hand, only 18 percent of the porcelainized aluminum specimens

were {'excellent" and 61 percent rated "very poor," Durability

ratings for the glass and aluminum specimens averaged about midway

between the porcelainized steel and porcelainized aluminum. Generally, priming of the porous joints did not improve durability.

Test data showed that durability was related to hardness. Results for 91 samples in concrete joints showed the lowest hardness

group (10-21) averaged the best durability rating, and the highest

hardness group (51-58), averaged the poorest durability. Bubbles

formed in joints during the durability test in 26 of 93 samples

tested in concrete joints, A relationship of bubble formation with

low hardness was indicated.

In the study of durability, 54 percent of the 71 samples ex- posed outdoors for 21 months were rated "good" ; 1.4 percent rated

"fair" ; and 32 percent "poor," Durability tests made on 23 samples

by the standard laboratory method and by outdoor exposure showed

good correlation for 17 of 23 samples tested,

1, INTRODUCTION

This is a second progress report on the investigation of the properties

of rubber base calking materials for sealing joints in concrete, brick, stone

and other types of masonry construction. The investigation also includes the

study of the behavior of joint sealers in contact with non-porous building

materials such as porcelainized steel, porcelainized aluminum, aluminum and

glass

„

This report gives the final results of the study of the polysulfide base

joint sealers (Thiokols), Standard test procedures have been developed for

six physical properties which will eventually be included in a purchase specification for polysulfide base sealers. Also included are laboratory test results, analysis of the data and results of outdoor exposure studies,

2, DESCRIPTION OF SAMPLES

All samples consisted of two separate components, base and accelerator,

which were mixed immediately before use, in accordance with the manufacturer's

direct ions

,

The samples were classified by the producers as either non-sag or flow;

the latter specified for horizontal joints only. Some producers submitted

samples labeled "hard," "soft" or "regular" which designated the relative

hardness of the cured rubber.
,

‘
3 „

The samples (in the cured state) comprised several colors, including

white, neutral or natural, aluminum, gray, tan, brown, red, and black,,

For report purposes each sample was given a laboratory designation

in the form of a number and letter i the number specifying the producer

and the letter, the compound,, Identification of all samples are given

in a separate list attached to this report,,

3„ PHYSICAL TESTS

3,1 Staining and color changes

3.1.1 Standard test procedure

1 / The following test procedure (summarized version)— was developed for

predicting the staining and color change tendencies of polysulfide base

joint sealers t

A mortar mixture consisting of 1 part white portland cement, 1/2 lime

and 3 parts graded Ottawa sand (by volume) is placed over the entire sur- face of a thin aluminum plate having dimensions of 6- by 2 3/4 to a depth

of 1/4 in. and struck off flat. This is accomplished with the aid of a rectangular brass frame, 1/4 in. thick with an opening having the same dimensions as the aluminum plate. After 4 hr curing of the mortar in air

at 74 ± 2°F, 30 g of freshly mixed sealant (previously conditioned for

24 hr at 74 ± 2°F and 50 ± 10 percent humidity2J is spread over the mortar

leaving a half inch margin of mortar uncovered by the sealant „ Two such

specimens are prepared.

After an exposure period in air at .standard conditions, one specimen

is exposed in an "Atlas Weatheromefcer nTMi/ (single or double arc) for 200 hr

and the other specimen Is exposed In the laboratory at standard conditions

for the same period. At the end of the exposure period, the specimens are examined for color changes and stains.

JV The standard test procedures given in this report are condensed versions

of the complete procedures and de not include some of the detailed re- quirements that will eventually be included in a purchase specification.

2/ Temperature of 74 ± 2°F and relative humidity of 50 ± 10 percent are referred to as "standard conditions" in this report.

3/ The Weather©meter was operated on 51=9 cycle, i.e. 51 min of light and

9 min of water and light.

4.

3.1.2 Results

Table 1 summarizes the results obtained on 31 samples of calkings

tested in accordance with the procedure described above,, (The duration

of exposure in the Weatherometer and laboratory was 500 hr instead of

200 hr. It was found later that the shorter exposure produced the same results , and was therefore included as such in the standard test).

Twenty five of the 31 samples exposed both at standard conditions

and in the Weatherometer produced stains on the mortar backing „ The

results in table 1 indicate that 10 samples producing intense red stains

after exposure in air at standard conditions caused reddish brown stains

of slightly less intensity in the Weatherometer . The stains described

in the table as slight were shades of yellow, tan or brown, 0

In regard to the color changes of the calkings after 500 hr in the

Weatherometer, the whites,, gr ays , neutrals and tans darkened to varying

degrees . The aluminums and blacks were hardly affected. Changes in

color after exposure in the laboratory at standard conditions were insignificant.

Figure 1 illustrates the types of staining obtained on 5 samples of

joint sealers.

In actual installations polysulfide calkings with staining tendencies will produce stains of greater intensity (usually red) when exposed

on the north side of a structure. When installed on the south side the

stain usually is brownish red and the sunlight tends to lighten the stain

as time passes. The Weatherometer test produces the effect of a southern

exposure while the test made under standard conditions simulates conditions on the north side of a structure or an indoor exposure.

3.2 Slump or flow test

3.2.1 Standard test procedure

The following test procedure was developed for determining the slump

tendencies of polysulfide base sealers, non-sag type;

The sample in the original container is first conditioned at standard

temperature and humidity for 24 hr. At the end of this time a portion of

the freshly mixed sample is placed in a clean aluminum trough 1/16 in.

thick, 6 in. long, 3/4 in. wide, and 1/2 in. deep, with the back of the

trough extending an additional 2 in. After the calking is struck flat on all exposed surfaces, the trough is immediately placed in a vertical

position in an oven for 24 hr at 122 ± 2°F„ At the end of this period

the amount of slump is measured from the lower end of the trough to the

lowest point assumed by the compound. Measurements are made to the nearest 1/16 in.
*

*
3.2.2 Results

Table 2 gives the results of the slump tests for each of the 24 sam- ples tested in the standard trough (designated No. 2) and also in a trough

6 in. long;, 3/8 in. wide and 3/4 in. deep (No. 1 trough).

Of the 24 samples tested only one slumped excessively (1/2 in. in

both troughs). Twenty one samples showed no slump at all when tested in

the No. 1 trough, and 17 samples did not slump when tested in the No. 2 trough.

Figure 2 illustrates the types of troughs used in the test as well as examples of slumping and non- slumping compounds.

As stated in the first progress report, slump in a polysulfide base

sealer is an important handling property of the material. On the job, a slumping compound, applied to a vertical joint can cause poor workmanship,

unsightly appearance and delay in installation.

3.3 Tack- free time

3.3.1 Standard test procedure

The following standard test procedure has been established to determine the tack-free time of the po'lysulfide base calkings?

After conditioning the samples in the original container for 24 hr at

standard temperature and humidity a portion of the mixed compound is spread

on a thin aluminum plate over an area of approximately 5- by 1- by 1/4-in.

thick. A template is used to aid in spreading the compound and also striking

off flat the top surface. The specimen is then exposed in air at standard

conditions for 72 hr.

At the end of the applicable tack- free time (72 hr) a 6- by l~in„ strip

of polyethylene film, measuring 0.004 ± 0.002 in. in thickness is pressed on

to the top of the calking for a period of 30 sec with a 30 g brass weight

approximately 1.7- by 1- by 1/8-im. thick. The film is then progressively

withdrawn at right angles to the compound. The sample is considered tackfree if the film pulls off without any calking adhering to it.

3.3.2 R.e suits

The tack-free time test was applied to 22 polysulfide base compounds

and the results are given in table 3. Of the 22 samples only 3 failed the

test.
'
I 6 ,

Compounds remaining tacky in installations for long periods of time

tend to hold dirt and dust which results in an unsightly appearance,

3,4 Application 3,4,1 life and ease of extrusion

Standard test procedure

3,4,

1,1

Non-sag type

The following test procedure was developed to determine the application or pot life as well as the ease of extrusion of polysulfide base joint

sealers t

A Brookfield Viscometer, Model. RVF, fitted with a No, 7 spindle rotating at 2 r„p,m„ is used to make the determinations. The sample in the original container is first conditioned for 24 hr at standard temperature and

humidity. After mixing thoroughly about 300 g of base and accelerator, the

compound is placed into a gill capacity can (with friction rim removed),,

slightly over filling the can. The calking is struck off flat with the

edge of a spatula. The spindle is slowly brought down to the middle of the

compound, and then lowered to the level of the standard immersion mark indicated on the spindle. Any voids around the spindle are filled in with

the aid of a small spatula. The Viscometer motor is turned on and readings

on the 0 to 100 scale are taken after 1 min (initial reading) and at. periodic intervals thereafter. The motor is turned off after the initial reading, and turned on again one min before the following reading is taken.

The test is stopped either at the end of 3 hr, or when the pointer reaches

the end of the scale (100 mark), depending on which comes first,

3,4,

1,2

Flow type

The test procedure described above for the non-sag type compounds is

also used for the flow type except that the speed of the Viscometer motor

is made to operate at 10 r,p„m, instead of 2 r,p,m„ The size of the spindle remains unchanged. Application life tests were made on eight flow type

compounds using the standard test procedure,

3,4,2

Results

The first progress report gave the results of application life tests

of 29 samples of the non-sag type using the standard test procedure described above. Twelve of the 29 samples were relatively rapid curing com- pounds since the pointer reached the scale limit of 100 before 3 hr. For

the remaining 17 samples the test ran. the full 3 hr indicating relatively

slow curing compounds.

1
‘
7.o

The results of the tests for application life on eight flow type com- pounds are given in table 4. Five samples showed rapidly curing tendencies

while the remaining three stayed soft for 3 hr.

A determination of the ease of extrusion of a compound can be made

by placing a maximum limit on the initial scale reading in the standard

application life test.

A series of tests were made to determine the feasibility of using an

air calking gun (Semco brand) operated under a specific pressure,, temperature and humidity for measuring application life. This was done by extruding 6 oz of a compound from a filled 12 oz cartridge at 50 lb pressure at

standard conditions of temperature and humidity. After 3 hry the remaining

portion in the cartridge was extruded and the time required to empty it was

noted.

The results of these tests indicated that the method was not as dependable as the Viscometer method. Several tests made on single samples gave

variable results. Another disadvantage of the method was the relatively

large amount of calking needed for each test.

The application or pot life of the polysulfide base calking may be

regarded as the most important of the handling properties. It can be the

single factor causing failure in a calking installation when an attempt is

made to force a rapidly curing compound into a joint.

3.5 Hardness

3.5.1 Standard test procedure

The instrument used for making the hardness determination is the Shore

Durometer (Model A) described in Federal Test Method for Rubber No. 601

Method 3021 and also in ASTM Standard D 676-551^, 1958,, part 9. All readings are taken by the instantaneous method.

The sample in the original container is first conditioned for 24 hr at

standard conditions of temperature and humidity. After mixing thoroughly

about 200 g of base and accelerator a portion of the mixture is placed into

two polyethylene molds with inside dimensions of 4- by 1 1/2 by 1/4 in. The

top surface of the compound is struck off with a spatula,, and the two speci- mens are stored in the laboratory at standard conditions of temperature and

humidity. When the compound has lost its tackiness (usually 2 days) it is

removed from the mold, placed on a 3- by 6-in. thin aluminum plate and

allowed to cure for an additional 12 days.
*
8

Immediately after the caring period hardness values are obtained on

the two specimens at standard conditions* A total of five readings are taken on the two specimens and the average reading is regarded as the

original value* One specimen is then exposed in a freezer at 0° ± 2°F

for 72 hr and the other specimen in an oven at 158 ± 2°F for the same period* At the end of the cold and hot exposure periods hardness values

are determined at the respective temperatures and also after a recovery

period for 3 hr at standard temperature and humidity* The average of

five readings on each specimen is the accepted value*

3*5*2 Results

Table 5 gives the hardness values obtained on 100 calking samples

obtained at 74°F<, 0®F, and 158®F* The recovery values after the cold and

hot exposures are also given* The last column in the table lists "hardness factor" values which represent average values of the five corresponding values given in the first five columns of the table*

Figures 3 and 4 illustrate the distribution of hardness values for

the three temperature conditions for all samples tested*

The data in figure 3 show that the average hardness value obtained at

0°F was 56 percent higher than the average at 74®F* On the other hand,

the hot treatment (158®F) caused no immediate increase in hardness over the original value, but was followed by a residual increase of hardness,

after recovery of 23*5 percent* (Fig* 4)*

3*5*3 Effect of extended exposures on hardness

3*5*3*

1

Exposure at 74®F

Seventeen samples of ealkings were exposed in air at standard conditions for periods of 7, 8, and 9 months* Figure 5 shows the effects of

the exposure on the hardness characteristics of the 17 samples*

Of the seven samples exposed for 9 months the increase in hardness

ranged from 7 percent to a maximum of 61 percent* In the 8-month exposure

group the increases ranged from 0 percent to 25 percent* In the 7 -month

exposure group three out of four samples from one producer showed no in- crease in hardness and the fourth increased 8 percent*

9,

3 , 5 * 3 * 2 Combined exposure^ 74 and 158°F

Five calking samples with original hardnesses ranging from 25 to 44

were exposed in air at standard conditions for 18 weeks,, followed by ex- posure in an oven at 158°F for an. additional 30 weeks * Figure 6 illustrates the effect of this treatment* The average increase in hardness

for all specimens during the first 18 weeks was 36 percent* The subsequent 6 weeks exposure at 1.58 °F raised the average increase in hardness

to 94 percent* However s during the final 24 weeks the average hardness

increased by only an additional 15 percent*

3* 5*3*3 Effect of outdoor exposure on hardness

Fourteen calking samples were exposed on the roof of the Mineral

Products Building for 16 months* Figure 7 shows the effect of the exposure on the hardness values* The hardness increases ranged from 0 percent

to 147 percent with an average increase of 31 percent for all samples*

Reference to figure 7 indicates that three samples (producer No* 6) showed

no increase in hardness after exposure* It is worth noting that three

other samples from the same producer likewise showed no increase in hardness after 7-months exposure at 74®F (see Fig* 5)*

(For relationship between hardness and durability,, see chapter on durability,

)

3*6 Durability (Bond-Ductility)

Durability tests (referred to as bond-ductility in previous reports) were completed on the calking samples s us rials as follows;

Concrete

Concrete block

Brick

Wood

Porcelainized steel

Porcelainized aluminum

Aluminum

Glass —

ing eight types of accessory mate93 samples tested

47 samples tested

53 samples tested

33 samples tested

39 samples tested

28 samples tested

14 samples tested

15 samples tested

10 .

3.6.1 Standard durability test procedure

The following test procedure was developed to predict the durability

of polysulfide joint sealers in installations where joint movement take

place

A joint sealer stretching machine accommodating three specimens at one time is used to make the tests. The machine,, with some changes in

design^, is similar to the one described in Fed. Spec. SS-R-406-C,, Road

and Paving Materials,, Method 223.11. (See Progress Report No. 1 for

Photo.

)

The dimensions of the porous accessory blocks used in the testing of

the joint sealers are 3- by 2- by 1-in. The dimensions of the non-porous

materials are 3- by 2-in. with the thickness depending on the material

available for the test.

The test joint is prepared by making a sandwich of two similar accessory blocks separated by two aluminum spacers and held together by a rubber

band or clamp. After conditioning the sample for 24 hr at standard temperature and humidity. freshly mixed calking is placed between the spacers

forming a filled joint 2- by 1- by 3/8-in. hJ

Following a curing period of 14 days in air at standard conditions^

the spacers are separated from the calking and the specimens are tested in

accordance with the following cycle;

(a) Specimens are heated for 24 hr in an oven at 158 ± 2°F (with the

aluminum spacers between the blocks).

(b) Specimens are allowed to cool to room temperature (74 ± 2°F).

(c) Specimens are immersed in distilled water for 7 hr.

(d) Specimens are surface dried and placed in a freezer for 8 to 16

hr.

(e) Specimens are placed (frozen) in the machine and extended at

O^F,, 50 percent of the original width, at the rate of 1/8 in. per hr.

(f) The joint is held in the stretched position with 9/16 in. spacers

for 3 hr at 0°F followed by 3 hr at 74°F„

4 / After making a considerable number of tests with other joint sizes,

the 2- by 1- by 3/8 in. joint was found to be the most practical

size for a standard test.
.
11 .

(g) Specimens are placed with the original 3/8 in. spacers in the , oven and the cycle repeated until a total of three cycles are completed.—

3.6.2 Criterion of failure in the durability test

After step (f) in the cycle was completed, the three test specimens were examined for bond and cohesion breaks and an estimate made of the

loss in bonded area in square inches for each specimen. The loss in

bonded area was estimated as the sum of the losses on both sides of a given joint.

Although most of the failures occurred as bond breaks, some failures

were characterized by cohesion breaks in the calking, and by failure of

the accessory material itself. (Fig. 8). A complete bond failure in a specimen was defined as a failure resulting in an area loss of 2 sq in.,

regardless of whether this figure represented the loss on a single side

or the combined loss on both sides of a joint. When two or three specimens showed complete bond or cohesion failure, the test was stopped re- gardless of the number of cycles completed. In all other cases the tests

were continued through the five cycles.

The following formula for evaluating the durability of the calking

samples was used:

Durability Factor, D 1 “ A (6-C)

1 where A - bond or cohesion loss for each specimen in sq in.

C - number of cycles completed

For example, when the three specimens showed complete bond or cohesion

failure after the first cycle, the. Durability Factor was determined as follows

;

D

1 - A (6=C) - 2 (6=1) = 10

For 3 specimens D - 3 x 10 ~ 30

In a second example where the bond failure occurred on all three

specimens after the fourth cycle, the Durability Factor, D , was calculated as follows:

D « A (6-C) - 2 (6-4) - 4

For 3 specimens D ~ 4 x 3 - 12

J>/ The test results described in this report are based on a five cycle

treatment

.
IIII
12

For report purposes performance ratings were assigned to the Durability Factors as follows?

0 to 5 ~

6 to 10 =

11 to 15 -

16 to 20 =

21 to 30 "

"Excellent"

"Good"

"Fair"

"Poor"

"Very Poor"

3.6.3 Durability test results

3. 6.3.1 Effect of accessory material, on durability

of calkings

Table 6 gives the averages of the durability factors obtained for

all samples tasted with eight types of accessory materials. Figures 9

and 10 show the distribution of the durability factors for the porous and

non-porous materials, respectively.

In table 6 it is shown that the average durability factors for the

porous accessory groups ranged from 11.2 for the concrete block to 12.8

for concrete,, with the values for wood and brick in between. However,

the results obtained on the non-porous materials showed wide differences

in performance. Porcelainized steel gave the best performance and

porcelainized aluminum, the poorest.

Reference to the data in figure 9 indicates that 39 percent of the

concrete samples tested were rated "excellent, " 20 percent "very poor,"

and the remaining samples distributed somewhat evenly .from "good" to

The results in figure 10 indicate that the best performing material

in the non-porous group was porcelainized steel with 72 percent of the

samples rated "excellent" and 18 percent rated "very poor."

Figure 10 also indicate® that the lowest durability rating of the non- porous group was obtained by the porcelainized aluminum samples with only

18 percent in the "excellent category" and 61 percent rated "very poor."

The average value of glass and aluminum was approximately halfway between

the porcelainized steel and the porcelainized aluminum.

3. 6. 3.

2

Relationship between color and durability

In table 7 are listed the durability factors in relation to the

various colors of the calkings. The results indicate that the best performing compounds were the tan, neutral and gray, while the black and

the aluminum were the poorest.

3 .6. 3

.3

Relationship between brand of calking

and durability

In table 8 the durability factors are shown in relation to the producers of the various calking samples. The results indicate that producers 6 and 11 show the best performance ratings while prodijcers 4, 13,

and 23 show the poorest performance.

3. 6. 3.

4

Relationship between hardness and durability

A considerable amount of experimental data has been accumulated during the investigation with the purpose of establishing a correlation between hardness of the polysulfide calkings and durability.

Figure 11 illustrates the correlation obtained between original hardness values and durability factors for 91 calking samples tested in con- crete joints. In the sample group with the lowest hardness (10 to 21)

only two of the 15 samples tested had "very poor" ratings. The group with

highest hardness range consisted of six samples all with durability factors

in the "very poor" catagory.

In figure 12, a correlation similar to that shown in figure 11 was obtained between hardness factor and durability. Hardness factor is defined

as the arithmetical average of five hardness values, i.e. 74°F, 158°F, 0°F,

recovery from 158°F and recovery from 0°F.

3.

6.3.5

Bubble formation in durability specimens

It was noted that during the cycling of the specimens in the durability

test there was a tendency for many calking samples to form bubbles in the

joints. The bubbles formed mainly in the calkings in contact with porous

accessory materials. In a typical case, the bubbles would first appear

after the first or second heating in the cycle, increase in size during

the water immersion, and become still larger during the subsequent cycles.

Figure 13 illustrates typical, bubble formations observed in polysulfide com- pounds in concrete joints.
’

‘

•
In rating the performance of test specimens with bubble formation,

the presence of the bubble was not taken into account if the latter was

closed. As a result there was a tendency for specimens with closed

bubbles to have high performance ratings since the presence of the

bubble allowed the calking to be stretched with less than normal stress

on the bond.

3. 6.3. 5.1 Bubble formation and hardness

Of the 93 samples tested for durability in concrete joints, 26 sam- ples formed bubbles in the joints. A study of the hardness characteristics of the 26 samples revealed that the average original hardness

value of the group was 25, or 26 percent less than the average for all

specimens tested.

3.7 Outdoor exposure tests of calkings in concrete joints

During the course of the investigation of the polysulfide base

joint sealers as many samples as possible were exposed to the weather

for durability studies. To date 143 samples have been exposed up to

periods of 21 months.

For this purpose reinforced concrete troughs were fabricated, each

14 in. long, 8 in. wide and 1 3/4 in. deep, and containing two joints,

each 11 in. long, 3/4 in. deep and 3/8 in. wide. At first the calkings

were placed in primed and unprimed joints. But after about a year's observations results indicated that slightly more failures occurred in

primed than unprimed joints. It was then decided to expose new samples

in unprimed joints only. Each joint was stretched 1/32 in. every 3

months during the exposure.

3.7.1 Results

Table 9 gives the results of observations and tests made on 71

polysulfide base calkings exposed to the weather for 21 months. The

joints were rated "good," "fair," or poor." From the data presented in

table 9 it was found that 51 percent of the samples in the primed joints

and 54 percent of the samples in the unprimed joints received "good"

ratings. Also indicated is the fact that 38 percent of the calkings in

the primed joints and 32 percent in the unprimed joints were rated "poor."

Twenty-one of the 143 samples exposed developed bubbles in the joints in

varying degress. (Fig. 14). Original hardnesses which had been obtained

on 12 of the 21 samples averaged 27. This supports the previous finding

that bubbles tend to form in the compounds of low hardness.

15.

3.7.2 Relationship between durability factor and outdoor

exposure test results

An attempt was made to correlate durability factors (concrete joints)

with ratings obtained in the exposure tests of 23 samples. Seventeen sam- ples had been exposed for 21 months and 6 samples for one year.

The results of this comparison are given in. table 10. Of the 23 sam- ples tested, 17 samples showed "good” correlation, two showed "fair" and

four, "poor" correlation.

USCOMM-NBS-DC

Table 1, Staining and color change properties of 31 polysulfide

base calkings*

1

? Sample

No„

»

* Color

' (mixed

1 compound)

f

f

I Stain on Mortar

!.Calking Color Change

1

1

1

?

1 Lcife o

After 500 hr in

f 74°F t Weatherometer

i After 500 hr in

' Weatherometer

f

1

1

f

1-1 ,Tan

f

, Red

!

, Red-brown

1.Very light gray

I

I

3-M

?.GrayI

, None

1

, None

1.Dark grayi

t

4-G

1

, Aluminum

1

, Red

i

, Red-brown

f.None1

I 4-H ,Gray , Red , Red-brown .Dark gray 1 4-J .White , None , None , Ivory f

6-0

t.White

?

, None

»

, None

1.Dark ivory

!

f 6-R .Aluminum , Slight yellow , Slight yellow , None f 6-S .Neutral , Slight tan , Slight tan .Dark brown t 6-T .Neutral , Slight yellow , Slight yellow .Dark brown ! 6-U , Black , Slight brown , Slight brown .None t 6-V .Aluminum , Slight brown , Slight brown .None 1 6-W , Neutral , Slight yellow , Slight yellow .Dark brown f 6-X .Neutral , Slight yellow , Slight brown .Dark brown ! 6-Y , Black , Slight brown , Slight brown .None f 6-Z .Gray , None , Slight yellow .Almost black I

7-B , Black

!

, Red

»

, Red -brown

?.None

1

1

s 7-C i Black , Red ( Red -brown ( None ? 8-F Aluminum ' Red

J Red-brown

? None

I 8-G Gray Red Red-brown Dark gray

I 8-H 1 Black * Red Red -brown None

? 8-1 ’ Black ' Slight yellow Red-brown None

1

« 8-J 'Aluminum

f

1 Red Red-brown

t None

f

t

T 13 -K 'Tan ' Red ' Red-brown 'Dark brown t 14 -K 'Gray

?

' None ' None

» 'Dark gray!

I

1

? 22-B 'Gray ' Slight brown ' Slight brown 'Dark gray 1 22-C 'Black ' Slight brown ' Slight brown 'None f 22-D 'Tan ' Slight brown ' Slight brown ' Br own I

23-A , Neutral , Slight brown

?

, Slight brown .Light brown I 23-B .Aluminum , Slight brown , Slight brown , None f 23 -D .Neutral , Slight brown , Slight brown .Dark brown 1 23-F .Black , None , None .None 1

Table 2. Slump values of 24 samples of polysulfide base calkings.

I

t

8

t

—

r—

Sample

No, ' 3/8

1

Trough #1

in. wide^ 3/4 in. deep

8

8

' 3/4 in.

8

Trough #2

wide,, 1/2 in. deep

8

8

8

8

8 8 in. 8 in. 8

! 1-1 0 8 0 8

I

1

8 3-M , 0

8

8 3/16

8

8

f

8

8 4-1 , 1/2

8

8 1/2

?

8

8

1

8 6-R i 08

8 1/4

8

8

1 6-S . 0 8 0 8

» 6-U , 0 8 0 8

I 6-V , 3/16 8 1/4 8

1 6-W , 0 8 0 8

8 6-X , 0 8 0 8

f 6-Y , 0 8 0 8

i 6-Z , 0 8 3/16 8

? 6-AA i 0 8 0 8

8

y

8 7-E 1/16

8

8 1/16

8

8

8

I

V 8-F . 08

8 0

8

8

, 8-G . 0 8 0 8

8 8-H . 0 8 0 8

, 8-1 . 0 8 1/16 8

? 8-J . 0 8 0 8

8 14 -D ' 0 8 08

8 14-E ' 0 8 0 8

8 14 -F * 0 8 0 8

8 14-J ' 0 8 0 8

8 14-K « 0 8 0 8

8 14-L » 0 8 0 8
'
Table 3. Results of Tack-Free time tests on 22

polysulfide base calkings.

Sample No. Tack-Free^, 72 hr test

4-D

4-1

Passed

Passed

6-D

6-0

6-S

6-X

Failed

Failed

Passed

Passed

7-B Passed

8-1

8-K

Passed

Passed

9-B Passed

10-F Passed

11-H Passed

13-E

13-F

13-K

Failed

Passed

Passed

14-K

14-L

Passed

Passed

15-D

15-E

Passed

Passed

21-D

21-E

Passed

Passed

23 -A Passed

Table 4. Application life tests of polysulfide base

calkings using the Brookfield Viscometer,,

(flow type compounds)

9

1

!

?

9 Sample , Viscometer

(0 - Readings

100)

I

?

1 T ime

1

f

1

1

t

No. ,*

f Minimum

?

1 Maximum

I

?

f

1

9

t

f 6-G , 6 0 0?

V 100

?

1 50 min

J

1

?

9

I 6-T , 6„0»

f 100

I

I 90 min

?

»

1

? 9-F , 27.5

»

I 100

1

1 10 min

f

1

9

9 12-D , 26.5

?

I 62» 8

?

f 3 hr 1

9

9 14-H , 5.5

?

f 9.5

1

f 3 hr

f

T

9

f 14-1 6.5

1

9 13.3

I

I 3 hr

1

1

9

f 23-F 24,5

f

1 100

1

1 40 min

?

9

9

9

9

? 23-E f

?

82 „ 5

1

?

!

100

f

I

?

2 hr

1

f

9

Table 5. Shore "A" Hardness Values of 100 polysulfide base calkings

1

?

t Sample

No,

t

0rig o value

74°F

0°F

72 hr

t

' Recovery

' from

' 0 °F

t

158°F

72 hr

i i

' Recovery '

' fr om '

' 158°F '

i i

Hardness

factor *

t

y

y

y

y

?

» 1-F 32 51

1

» 40

y 32I t

' 40 ' 39

y

i

' 1-G 32 52 1 36 32 i 44 ' 39 y

» 1-H 34 59 f 36 34 i 42 ' 41 i

. 1-1 33 51 ? 29 20 ' 37 ' 34 y

' 2-D 38 55 ¥ 40 ? 40 ' 48 ' 44 y

' 2-E 42 55 1 41 42 « 47 ' 45 y

' 2-F 38 50 f 40 32 ' 39 40 y

» 2-G 34 51 ? 35 38 ' 43 ' 40 y

' 3-E 32 49 ? 32 24 i 4i i 36 !

' 3-F 33 ¥ 53 ? 34 35 ' 40 ' 39 y

' 3-G 46 56 ¥ 41 44 ' 43 46 y

' 3-H 33 51 ¥ 34 41 ' 46 ' 41 y

, 3-1 30 61 y 33 38 * 48 « 42 y

' 3-J 38 56 f 36 39 > 46 1 43 y

• 3-K 31 56 ? 34 36 1 46 ' 41 »

' 3-L 25 48 » 26 29 ' 42 34 y

' 3-M 18 46 y 19 11 1 14 ! 22 y

' 4-G 39 64 ? 46 40 ' 51 48 y

' 4-H 22 56 i 35 39 j 46 ' 40 y

' 4-1 44 1 60 i 43 49 ' 51 « 49 y

' 4~J 32 63 y 29 28 • 44 • 39 y

* 6-A 15 40 y 16 7 ' 16 ' 20 y

» 6-H 20 37 f 20 15 ' 24 » 23 y

' 6~J 16 34 i 22 12 ' 16 ' 20 y

' 6-K 16 43 y 19 ? 12 ' 20 22 y

' 6-L 16 53 l 18 3 15 ' 22 25 y

' 6-M 35 58 y 34 27 • 37 ' 38 y

1 6-N 14 41 ! 16 12 ' 18 ' 20 y

• 6-0 21 41 y 21 15 i 24 ' 24 y

' 6 -P 12 34 i 12 6 ' 14 ' 16 y

' 6-Q 34 56 y 33 27 ' 37 ' 37 y

' 6-R ' 24 47 i 24 19 • 28 28 y

' 6-S 1 24 46 ? 24 20 ' 26 28 i * Average of 5 hardness readings i 0 e.^ 74°F^ 0°F^ 158°F, recovery after 0°F,

and recovery after 158°F 0
f
Table 5 (Continued)

1

9

9

9

9

I Sample ' No,

t

?

Orig,

value

74°F

0°F

72 hr

i

1 Recovery

' from

' 0°F

I

1

1

' 158°F

' 72 hr

1

» Recovery ' from ' 158°F

1

Hardness

factor *

!

1

f

1

!

9

9 6~T | 19 36

?

, 19 r

?

, 12 20 21

f

!

9 6-U , 20 46 , 20 , 13 23 24 f

9 6-V , 54 62 , 57 , 56 63 58 1

9 6-W , 45 67 , 43 , 41 52 43 1

9 6-X , 35 62 , 36 , 35 44 42 9

T 6-Y , 38 54 , 36 , 39 45 42 9

? 6-Z , 18 46 , 16 , I 7 23 24 1

V 7 -A' 49 60 48 48 56 52f 7-B 50 68

! 53 58 63 58

9 7"C

; 32 53 35» ! 32 42 1 39

I

9 8 -A 10 37

9 10

9 12

1 24 19f 8-B 27 52 29 34 48 38

8-D 16 44 13

! 15 21 22

8-E 47 61 47 , 53 54 52

8-F 32 50 32 39 49 40

8-G 28 56 35 29 40 38

8-H 26 53 30 32 44 37

8-1 50 61 50 53 57 54

8-J 29 52 33 31 47 38

9 8-K ? 21

» 52 ! 21 20 ? 33 29 1

9 9 9-A ,

? 49 59 529

, 50 53 53

9 9-B 45 56 44 45 50 48

9-C 50 ! 60 49

! 52 54 53

9 9 - F

! 55 t 59 52 , 56 58 9 56 9

9 10 -Af 36 57

9 36 36 42 41

9

10-B 58 67 57 58 62 60

9 10-D

I 57? 63 64

9 60? 60

1 619

9 11 -A

V 33 54 34

?

, 47

I 53 44

9

11-E 40 58 37 46 51 46

11-F 17 46 16 32 40 30

11-G 41 57 41 43 52 47

9 11-Ht 44

f 60 46 » 50? 58 ? 52

9

Table 5 (Continued)

5 1

f ?

> Sample 1

' No. '

V 1

Orig,

value

74°F

0°F

72 hr

9

' Recovery

' from

' 0°F

9

9

9

' 158°F

' 72 hr

9

' Recovery

' from

' 158°F

9

I

i Hardness

t factor *

9

I

9

9

1

9

' 12 -A ' 42 62 ' 44 ' 46 ' 54 ' 50 9

' 12-B ' 43 57 ' 41 ' 43 1 48 ' 46 9

' 12-C * 42 62 ' 41 ' 44 ' 52 ' 48 9

' 12-E ’ 41 54 ' 42 ' 44 1 50 ' 46 9

' 12-F ' 39 56 ' 37 ' 40 ' 47 ' 44 9

' 12-G ' 28 52 ' 32 ' 35 ' 46 ' 39 9

' 12 -H '

? 9 45 60 ' 469

' 48

9

' 57 ' 51

9

9

9

' 13~F ' 36 54 ' 36 ' 39 ' 45 ' 42 9

' 13-H ' 24 54 ' 26 ' 30 ' 43 ' 35 i

' 13-1 ' 21 42 ' 20 ’ 28 ' 36 ' 29 9

' 13-J '

9 V 24 44 ' 26

9

' 33

9

' 43 ’ 34

9

9

9

' 14 -A ' 36 56 ' 36 ' 31 ' 41 ' 40 9

' 14-D ' 23 56 ' 26 16 ' 29 ' 30 9

' 14 -E ' 34 65 ' 32 5 26 ' 47 ' 41 9

' 14-F ' 29 61 ' 30 ' 21 ' 38 1 36 t

' 14 -G ' 17 26 19 ' 25 ' 24 ' 22 9

’ 14-J ' 32 63 29 ' 28 ' 44 ' 39 9

' 14 -K 1 24 56 ' 22 ' 20 ' 24 ' 29 9

' 14 -L *

9 9 28 44 ' 29

9

' 26

!

' 28 ’ 31

9

9

9

' 15-B ' 46 57 ' 46 ' 48 ' 51 ' 50 9

' 15 -E ' 41 54 ’ 52 ' 46 ' 40 ' 47 !

' 15-F '

9 9 16 42 ' 15

9

5 26

9

' 36 ' 27

f

9

9

' 21-A 1 23 51 5 27 ' 38 ' 33 ' 49 9

' 21-B ' 36 54 ' 36 ' 43 ' 52 5 44 9

' 21-C '

9 9 34 61 ' 35

9

' 35

9 52 ! 43

J

9

9

' 2 2 -A ' 33 56 ' 31 ' 26 ' 41 ' 37 9

' 22-B ' 26 51 ' 21 ' 26 ' 34 ' 32 9

' 22-C ' 47 66 ' 49 ' 55 ' 60 ' 55 9

’ 22-D 1

9 9 30 46 ' 30

9

' 23

9

' 33 ' 32

9

9

9

Table 5 (Continued)

7

?

, Sample

, No.

7

t 7 Orig,

' value ’

' 74°F

7 7

0 °F

72 hr

t

»

1

1

I

Recovery

from

0°F

f

f

1

f

f

158°F

72 hr

7 Recovery

from

' 158°F

1

?

1

I

?

I

7

7 Hardness t factor * t

7

?

' 23-A

7 1

' 40 56

I

? 43

f

f 43

t

' 51

f

7

7 47

' 23-B ' 46 61

I 46 7 45 ' 59f 51

' 23-C ' 58 67

I 60 ? 59 ' 62 7 61

' 23-D ' 25 ' 51 ! 25

1 18 ' 31 7 30

' 23 ~E ' 33 56 ? 35 7 32 ' 42 7 40

' 23-F

?

! 51

? f 61 J

! 51 f

1 50 ’ 55

7

7

7 54

7

Table 6. Summary of Results of Durability Test on polysulfide base calkings.

f

' Accessory

' material

i

I

?

9

II

No. of

samples

tested

1

' Durability

' Factor (avg.)

9

9

9

9£

I

' Concrete*

?

9

f

9 93

9

9

9 12.8

9

9

9

' Brick

1

9

? 53 9

9 12.0 99

’ Wood

f

1

9 33 9

9 12.4 !

9

' Concrete block

9

1

9 47 9

9 11.2 9

9

' Porcelainized steel

1

1

1 39 99 9.4 !

9

7 Porcelainized aluminum

?

I

9 28 99 22.1 9

! Aluminum

i

9

! 14 9

9 19.6 ?9

’ Glass

?

?

9 15 1!

9 14.4 9

9

* All accessory materials except wood were tested without

a primer.

Table 7. Relationship of color to durability of calkings

Color of No. of Durability

calking samples factor

tested (average)

Aluminum 21. 14.7

Tan or neutral 22 8.5

Gray rH CO 9 „ 2

Black 29 15 „ 6

White 3 12o 4

Table 8. Relationship of brand of calking to durability.

Producer

No*

No. of

samples

tested *

Durability

factor

(average)

1 4 11c 7 2 4 10.3

3 6 12.6

4 4 19.9

6 18 5.7

8 9 10.7

11 5 5o4

12 5 8.4

13 4 18.9

14 9

rH CM 22 4 7.9

23 6 19.4

tested ih concrete joints

Table 9 Results of 21 months exposure to the weather of

71 samples of polysulfide base calkings in

concrete joints, 2/

Condition of Joints 2 /

No, 0

0 Color ?

3 Primed 0

1~A

0

1/ Neutral

3

V Good

0

? Poor

1-B ? Aluminum 0 Poor 3/ ? Poor

1-C U Brown 0 Good 0 Good

1-D 3 Gray 3 Good

4/

? Good

1-E 3 Black. 3 Good t Poor

2-A

0

3 Aluminum

0

3 Good 4/

?

( Good

2-B 3 Gray 3 Fair i Good

2-C 0 Tan 3 Good 0 Good

2-B 3 Black 0 Poor i Good

3 -A

3

3 Aluminum

3

3 Poor 3,4/

0

! Poor

3-B ? Gray 0 Fair * Good

3-C 0 Tan 0 Good

5/

3 Good

3-D 3 Black 3 Good i Good

4 -A 7/

3

3 Gray

0

3 Good

0

? Good

4-B 8/ 3 Gray 0 Good

(leaked)-/'"

i Good

4-C 0 Aluminum 0 Poor i Fair

4-D 3 White 3 Poor i Poor

4-E 3 Black 3 Good

2/

» Good

4-F 3 R.0(d 0 Good j G OOCiL

5-A

3

0 Tan

3

0 Fair

2/

3

? Fair

5~B 3 Gray 0 Fair , Poor

5"C 3 Aluminum 0 Poor , Fair

5-D 3 Black 3 Poor , Fair

6 -A

6/

0

0 Neutral

0 Good9

, Good

6-B 3 Neutral 3 Poor (leaked) , Good

6-C

6/

3 Gray 3

0

Poor (leaked) , Fair

6-D 0 Gray Fair 2/ , Good

6-E 3 Aluminum 0 Poor , Poor

6-F

6-G 6/

0

0 Black

Black

0

0 Poor

Good

, Good

j Good

7 -A

0

3 Black

3

0 Poor (leaked)

0

, Poor

Unprimed

3/

(leaked) —!

4/

3,4/

4/

(leaked)

1/

3/

(leaked)

3/

(leaked)

Table 9 (Continued)

Sample

No„

8-A

..or

Aluminum

Condition of Joints ” r Primed , Unprimed

Good

8“B 8/( . Aluminum ' Poor

8-C ]f * Brown * Good

8-D 7/ « Black » Good

8-E 8/ » Black i Poor

9 -A 0 Aluminum ' Fair

9-B 8 Tan 1 Poor

9-C 0 Black * Poor

9“D 6/ i Aluminum > Poor

9 -E 6/ i Tan • Poor

9=F 6/ i

8 Black 1 Poor

10 -A 0 Gray » Good.

10 -B 0 Gray * Poor

10-C 0 Aluminum ® Good

1,0 “3 0 Black 1 Poor

10-E 6/ t Black * Good

10 -F ?

0 Gray * Poor0 11 -A 0 Gray 11 Poor

11-B 6/ u Gray 1 Good

11-C 0 Tan * Good

11-D 0

0 Black ' Good

12 -A 0 Gray ® Good

12 -B ? Tan * Good

12 -C 0 Black * Good

12-D 6/ » Black s Poor

13 -A

0

0 Tan

0

t Poor

13 -B ? Gray » Fair

13 -C 0 White d Good

13 -D ? Aluminum * Good

13 -E 0 Tan t Good

13 -F ? Black „ Good

* Good

3,4/ » 3,4/ Poor

* Good

5/ * Good 5/

(leaked) ft/ 1 Poor (leaked)

4/

8

« Fair 4/

(leaked) * Poor (leaked)

(leaked) 5 Poor

' Fair

(leaked)

9 Poor (leaked)

(leaked) » Poor

9

< Poor

(leaked)

(leaked) « Poor (leaked)

4/ * Good 4/

(leak'.ed) » Poor

9 Good

(leaked)

(leaked) 8 Good

9

* Poor

» Good

1 Good

* Good

9

5 Good

* Good

1 Good

(leaked) » Fair

(leaked)

?

1 Fair

5/

1 Poor

9 Poor

1 Good

(leaked)

u G ood

, Fair

Table 9 (Continued)

V

9

9

9

Sample

No,

9

7

, Color

9

9

9 Condition of Joints —

9

9

9

I Pr imed

9

9 Unprimed

9

9

9

f 14 -A

1

* White

9

» Poor (leaked)

9

9 Poor (leaked)

9

9

9 14-B ' Gray » Good 5/ 9 Good 2/ 9

9 14-C * Black. « Fair 1 Poor ]

9

c 15 -A » Aluminum » Good I Good 9

9 15 -B » Aluminum » Poor (leaked) 9 Poor (leaked) 9

9 15 -C * Black » Good 9 Good 9

9 15 -D » Black » Good 9 Good 9

9 16 -A » Aluminum » Good 9 Good 9

9

9 16-B » Black

9

» Good

9

?

9 Good 9

9

1 / Galkings are non-sag type,, except where specified in a footnote,,

2/ Joints were stretched 1/32 in0 at periodic intervals to a total

of 7/32 in, or 58%, Condition of joints were rated as Good,,

Fair or Poor, Good; no bond or cohesion breaks present, or contains shallow break no greater than 1/2 in, Fair; shallow

bond or cohesion breaks totaling no more than 1 in* in length.

Poor; bond or cohesion breaks totaling more than 1 in, in length,

3/ Cohesion breaks,

4/ Crazing of surface,

5 / Air bubbles in compound,

6/ Flow type compound,

7/ Compound classed, as soft by producer,

8/ Compound classed, as hard by producer.

Table 10, Relationship between durability factors and exposure

test results for 23 samples, 2/

0

? Sample

0

1 Durability

f

0

¥ Outdoor Exposure s Correlation —

T

i

f No,

0 J

( factor

0 =

0 Bond or ,

?

*

? f ¥ cohesion breaks

0

0 2-C CM o

?

0

0 Absent Poor

¥

0

¥ 3-1 , 24 0 'Present 9 Good 1

0 3-K , 12 0 Absent , Good 0

0 3=L , 4,8 0 Absent s Good ?

0 6“M

0

, 30

0

0

0 'Present Good

?

0

0 6=N , 0,3 0 Absent , Good 9

0 6“Q » 0,2 0 Absent , Good 0

0

0 7“ A 30

0

0

0

0 Present

0 Good

¥

¥

0 8-A 8,0 0 Absent Good 0

0 8-B 13 ,

1

9 Present Fair ¥

? 8-D 00 Absent Good ¥

0

0 8~E 300

0 Present

0 Good 0

¥

0 9 -A ' 30 0 Present Good ¥

0 9“B 1 30 0 Present U 0OG. 0

1 9 “E 16,9 0 Present ' 9 Fair 0

0 9-F 27,5 0 Present Good

«

C 10-A 2,6 0 Present » Poor 3

0 10-B j 30 0 Present * Good 0

0 10 -D « 25 0 Present * Good 0

0

0 11 “A

0 3,

6

8

0

0 Present # Poor ¥

0

0 12=A

0

, 4 ° 6

0

0

p Absent , Good

?

0

0

0 13 =F

0 260

0

0 Absent ? Poor

0

0

0

0 15 -B

0 300

0

3 Present c Good

3

0

1 / Durability Factors were obtained with a sandwich of two concrete

accessory blocks containing a 2= by 1- by 3/8-xn, joint,, subjected to heating and cooling cycles and stretched 50 percent at

0

a F. The Exposure Tests were made with concrete troughs containing 11“ by 3/4= by 3/8-in, joints exposed to the weather and

stretched 1/32 in, every 3 months.

Staining

tendencies

of

some

polysulfide

joint

sealers,

(A),

Nonstaining

type

-

no

stain

appeared

after

500

hr

in

Weatherometer

.

(B,

C),

Specimens

with

deep

red

stains

after

500

hr

in

lab,

74°F,

(D,

E,

F),

Various

degrees

of

reddish

brown

staining

after

500

hr

Two

types

of

troughs

used

to

test

for

slump

of

polysulfide

calkings„

(A^,

D)^

Troughs

before

filling,,

(B,

E),

Nonslumping

compounds*

(C,

F),

Samples

showing

1/4

in*

slump*

NUMBER

OF

SAMPLES

30

20

10

0

50

40

30

20

ID

0

30

20

10

0

0 10 20 30 40 50 60 70 80 90 100

SHORE 'A' HARDNESS VALUES

FIG. 3 DISTRIBUTION OF SHORE 'A* HARDNESS VALUES

OBTAINED ON 100 SPECIMENS OF RUBBER BASE

CALKINGS
.
NUMBER

OF

SAMPLES

30

SHORE 'A' HARDNESS VALUES

FIG. 4 DISTRIBUTION OF SHORE 'A' HARDNESS VALUES

OBTAINED ON 100 SPECIMENS OF RUBBER BASE

CALKINGS.

SHORE

A

HARDNESS

CALKING SAMPLES

FIG. 5 EFFECT OF LABORATORY EXPOSURE AT CONSTANT

TEMPERATURE (74±2°F) ON THE HARDNESS VALUES

OF 17 CALKING SAMPLES

00o °

CM+ 1 00in CD -

ro ..

tu>

CNJO

ro

oo

CNJ

*fCMO

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FIG. 6

EFFECT

OF

EXPOSURE

AT

74

°F

AND

SUBSEQUENT

EXPOSURE

AT

158

°F

ON

THE

SHORE

HARDNESS

VALUES

OF5

CALKING

SAMPLES

SHORE

A

HARDNESS

70

65

60

3-E

55 i 2-F 8-E

50 —

45 -

40 —

35 -

3-F 3-H

2-6

l-F

I

30 —

25 -

1 7-

A

Q-D

20

15 -

6-H

NO CHANGE

6-J

12-E

14 - A

I

Lower end of each bar

indicates the original

hardness of the sample

Upper end indicates the

hardness after exposure

CALKING SAMPLES

FIG. 7 EFFECT OF 16 MONTHS OF OUTDOOR EXPOSURE

ON THE SHORE HARDNESS VALUES OF 14 CALKING

SAMPLES
'
Fig,

8

-

Types

of

failures

obtained

in

the

durability

test,

(A),,

Complete

bond

break

between

accessory

material

and

calking,

(B),

Failure

resulting

in

breakage

of

the

accessory

block

due

to

high

hardness

and

strong

adhesion

of

calking,

(C)

Cohesion

failure

of

calking.

POROUS

DURABILITY

ACCESSORY

MATERIALS

RATING

SBldlMt/S 30 39tflN30d3d

porous

accessory

materials

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non

-porous

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DURABILITY

FACTOR

30

10-21 21-30 31-40 41-50 51-58

SHORE 'A' HARDNESS

FIG. II Relationship between original shore hardness values and

durability factor for 91 samples of polysulfide joint

sealers tested in concrete joints
*
DURABILITY

FACTOR

30

25 —

20 —

15 —

10 —

5 —

0

FIG. 12

V,

Durability Equivalent

Factor Rating #15 Samples _

0-5 Excellent

6-10 Good

II -15 Fair

16-20 Poor

20-30 Very Poor

J%2.7 Samples

?5 Samples

Hardness Factor

Average of 5 Values:

Hardness at 74 °F,

_L

26 Samples

L_

0°F, 158 °f; Recovery

After 0°F and 158 °F _

1 L _ 16-31 31-40 41-50 514- HARDNESS FACTOR

Relationship between hardness factor and durability factor

for 91 samples of polysulfide joint sealers tested in

concrete joints

I I

Fig*

13-

Bubbles

formed

in

joint

sealers

in

durability

test.

(A),,

Joint

with

open

bubble,,

(B,

C)^

Joints

with

closed

bubbles.

r

Bubbles

formed

in

joint

sealers

after

exposure

to

the

weather

Left,

6

months

exposure,

open

bubbles

„

Middle,

21

months

exposure,

open

and

closed

bubbles.

Right,

6

months

exposure,

closed

bubbles.

U.S. DEPARTMENT OF COMMERCE

Frederick H. Mueller, Secretary NATIONAL BUREAU OF STANDARDS

A. V. Amin, Director THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering in the field indicated hv

its title. A brief description of the activities, and of the resultant publications, appears on the inside of the front cover. WASHINGTON, D.C.

Electricity and Electronics. Resistance and Reactance. Electron Devices. Electrical Instruments. Magnetic Measurements. Dielectrics. Engineering Electronics. Electronic Instrumentation. Electrochemistry.

Optics and Metrology. Photometry and Colorimetry. Photographic Technology. Length. Engineering

Metrology.

Heat. Temperature Physics. Thermodynamics. Cryogenic Physics. Rheology. Molecular Kinetics. Free

Radicals Research. Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid Stale Physics. Electron Physics. Atomic Physics. Neutron Physics. Radiation Theory. Radioactivity. X-rays. High

Energy Radiation. Nucleonic Instrumentation. Radiological Equipment.

Chemistry. Organic Coatings. Surface Chemistry. Organic Chemistry. Analytical Chemistry. Inorganic

Chemistry. Electrodeposition. Molecular Structure and Properties of Gases. Physical Chemistry. Thermochemistry. Spectrochemistry. Pure Substances.

Mechanics. Sound. Mechanical Instruments. Fluid Mechanics. Engineering Mechanics. Mass and Scale. Capacity, Density, and Fluid Meters. Combustion Controls.

Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifications. Poly- mer Structure. Plasties. Dental Research.

Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion. Metal

Physics.

Mineral Products. Engineering Ceramics. Glass. Refractories. Enameled Metals. Constitution and Microstructure.

Building Technology. Structural Engineering. Fire Protection. Air Conditioning, Heating, and Refrigeration. Floor, Roof, and Wall Coverings. Codes and Safely Standards. Heal Transfer. Concreting Materials.

Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics.

Data Processing System’s. SEAC Engineering Group. Components and Techniques. Digital Circuitry.

Digital Systems. Analog Systems. Application Engineering.

• Office of Basic Instrumentation. • Office of Weights and Measures. . BOULDER, COLORADO

Cryogenic Engineering. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Gas Liquefaction. Radio Propagation Physics. Upper Atmosphere Research. Ionospheric Research. Regular Propagation

Services. Sun-Earth Relationships. VUF Research. Radio Warning Services. Airglow and Aurora. Radio

Astronomy and Arctic Propagation.

Rudio Propagation Engineering. Data Reduction Instrumentation. Modulation Research. Radio Noise. Tropospheric Measurements. Tropospheric Analysis. Propagation Obstacles Engineering. Radio-Meteorology. Lower Atmosphere Physics.

Rudio Stamfords. High Frequency Electrical Standards. Radio Broadcast Service. High Frequency I in* pedanec Standards. Electronic Calibration Center. Microwave Physics. Microwave Circuit Standards. Radio Communication und Systems. Low Frequency and Very Low Frequency Research. High Fre- quency and Very High Frequency Rcsourcli. Ultra High Frequency and Super High Frequency Research. Modulation Research. Anlennu Research. Navigation Systems. Systems Analysis. Field Operations.