Post on 20-Mar-2018
Bench Tests for Characterizing Type X Special Fire Resistant
Gypsum Board –Repeatability & Reproducibility
Paul H Shipp, PhD, PE and Qiang Yu, PhDUSG Corporation
ASTM Committee E05
Symposium on Uncertainty in Fire Tests
June 16, 2011 – Anaheim, CA
Today’s Presentation
• Background
– Type X (special fire resistant) gypsum board
– Gypsum Association research program
• Three bench tests
• Correlation of bench tests to ASTM E119 tests
• Bench tests’ precision & bias
– Repeatability & reproducibility
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Type X gypsum board
• ASTM C 1396 – 09a
4.3 Gypsum Board, type X (Special Fire-Resistant):
4.3.1 …provides not less than 1 h fire-resistance rating for boards ⅝ in. thick or ¾ h fire-resistance for boards ½ in. thick applied…on each side of load bearing 2 by 4 wood studs…partition…tested in accordance with Test Methods E119.
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Problems with C1396 definition
• ASTM E119 load bearing wood stud wall– Test apparatus availability
• 10 furnaces in North America
– Expensive• $10k ~ $20k per test
– E119 test variability– Influenced by non-gypsum components
• Unsuitable for plant QA– Cannot provide timely feedback to production
process– Need small scale tests of gypsum board alone
Gypsum Association Research Program, 2003 - 2009
• Product Standard Task Group (PSTG)– Ad hoc task group– Objective:
• Develop improved definition of type X based on specific properties of the gypsum board alone.
• Program– Identify key properties– Develop suitable bench test(s)– Testing & validation
• Bench test round robins• Correlate bench test results to E119
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Fire Protection Membrane Performance Criteria
• Move with the framing
• No large cracks or fall-off
• Reduce heat transfer
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Three Bench Tests
• High-Temperature Core Cohesion– High-temperature strain (movement)– Does sample break upon deflection while exposed to fire?
• High-Temperature Shrinkage– Cracking– In-plane linear shrinkage at 1562°F (850°C)
• High-Temperature Thermal Insulation– Thermal barrier– Time rate of temperature rise at unexposed surface.
• Theory & description– Shipp, P. H., and Yu, Q., “Thermophysical Characterization of Type X Special
Fire Resistant Gypsum Board”, Proceedings of the Fire and Materials 2011 Conference, San Francisco, 31st January – 2nd February 2011, InterscienceCommunications Ltd., London, UK, p417-426.
– ASTM ballot C11 (09-04) item 1
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Correlation to E119*
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35
40
45
50
55
60
65
70
75
80
40 45 50 55 60 65 70 75
Pre
dic
ted
Fir
e R
esis
tan
cen
Ra
tin
g, m
inu
tes
Fire Resistance Rating, minutes
*Shipp & Yu, Fire & Materials Conference , 2011 Proceedings, p417-426.
Bench Tests – Precision & Bias
• Interlaboratory Studies (ILS)– American Gypsum Co. LLC
– CertainTeed Gypsum Inc.
– Georgia-Pacific Gypsum LLC
– Lafarge North America Inc.
– National Gypsum Co.
– PABCO Gypsum
– Temple-Inland
– United States Gypsum Co.
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Uncertainty Analysis
• Bias
– No standard reference material
• Precision
– Repeatability (r)
– Reproducibility (R)
– Coefficient of Variation (CV)
• ASTM E691-09e
– Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
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High-Temperature Core Cohesion Test
• Simple categorization test– Binary pass/fail result
• ILS– 7 manufacturers
– 4 different type X samples
– 1 manufacturer also tested non-type X gypsum boards (½” & ⅝”)
• Over 400 test specimens evaluated– No “false positive” or “false negative” outcomes
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High-Temperature Shrinkage Test
• 3 shrinkage round robins
– SRR1 & SRR2 = 7 labs
– SRR4 = 6 labs
– Test method progressively refined
• 4 samples per round robin
• 12 replicates per sample
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SRR2 – Sample ‘T’
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Material
T
Laboratory 1 2 3 4 5 6 7 8 9 10 11 12
A 0.043 0.040 0.052 0.053 0.044 0.046 0.041 0.040 0.050 0.053 0.044 0.044
B 0.040 0.037 0.047 0.045 0.043 0.045 0.038 0.036 0.045 0.046 0.045 0.051
C 0.039 0.043 0.042 0.037 0.044 0.044 0.039 0.046 0.044 0.041 0.044 0.043
D 0.040 0.041 0.045 0.044 0.039 0.038 0.037 0.043 0.042 0.041 0.036 0.036
E 0.043 0.047 0.041 0.043 0.044 0.040 0.039 0.048 0.041 0.043 0.047 0.042
F 0.042 0.044 0.046 0.046 0.038 0.038 0.041 0.044 0.045 0.045 0.037 0.038
G 0.042 0.044 0.046 0.046 0.042 0.040 0.043 0.045 0.046 0.044 0.044 0.042
H 0.015 0.012 0.014 0.021 0.022 0.020 0.018 0.018 0.013 0.018 0.013 0.013
h-critical k-critical
2.15 1.49
Laboratory Avg s d h k CV
A 0.046 0.005 0.006 0.669 1.381 10%
B 0.043 0.004 0.004 0.371 1.288 10%
C 0.042 0.003 0.003 0.284 0.782 6%
D 0.040 0.003 0.001 0.076 0.893 8%
E 0.043 0.003 0.004 0.374 0.812 7%
F 0.042 0.004 0.002 0.250 1.015 8%
G 0.044 0.002 0.004 0.416 0.557 4%
H 0.016 0.004 -0.023 -2.440 1.013 21%
Avg of cell avgs, x: 0.040 0.003 = Avg std dev Avg CV: 9%
Std dev of cell avgs, sx: 0.010
Repeatability std dev, sr: 0.003 Repeatability limit, r: 0.010
Reproducibility std dev, sR: 0.010 Reproducibility limit, R: 0.028
Test Results, xi,j
Material
T
Laboratory 1 2 3 4 5 6 7 8 9 10 11 12
A 0.043 0.040 0.052 0.053 0.044 0.046 0.041 0.040 0.050 0.053 0.044 0.044
B 0.040 0.037 0.047 0.045 0.043 0.045 0.038 0.036 0.045 0.046 0.045 0.051
C 0.039 0.043 0.042 0.037 0.044 0.044 0.039 0.046 0.044 0.041 0.044 0.043
D 0.040 0.041 0.045 0.044 0.039 0.038 0.037 0.043 0.042 0.041 0.036 0.036
E 0.043 0.047 0.041 0.043 0.044 0.040 0.039 0.048 0.041 0.043 0.047 0.042
F 0.042 0.044 0.046 0.046 0.038 0.038 0.041 0.044 0.045 0.045 0.037 0.038
G 0.042 0.044 0.046 0.046 0.042 0.040 0.043 0.045 0.046 0.044 0.044 0.042
h-critical k-critical
2.05 1.48
Laboratory Avg s d h k CV
A 0.046 0.005 0.006 0.669 1.381 10%
B 0.043 0.004 0.004 0.371 1.288 10%
C 0.042 0.003 0.003 0.284 0.782 6%
D 0.040 0.003 0.001 0.076 0.893 8%
E 0.043 0.003 0.004 0.374 0.812 7%
F 0.042 0.004 0.002 0.250 1.015 8%
G 0.044 0.002 0.004 0.416 0.557 4%
Avg of cell avgs, x: 0.043 0.003 = Avg std dev Avg CV: 8%
Std dev of cell avgs, sx: 0.002
Repeatability std dev, sr: 0.003 Repeatability limit, r: 0.010
Reproducibility std dev, sR: 0.004 Reproducibility limit, R: 0.010
Test Results, xi,j
SRR2 – Sample ‘T’
• Drop Lab ‘H’
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SRR2
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-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
S S S S S S S S T T T T T T T T WWWWWWWW X X X X X X X X
A B C D E F G H A B C D E F G H A B C D E F G H A B C D E F G H
Between-lab statistic, h
High-temperature shrinkage, RR2
SRR2
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-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
S T W X S T W X S T W X S T W X S T W X S T W X S T W X S T W X
A A A A B B B B C C C C D D D D E E E E F F F F G G G G H H H H
Between-lab statistic, h
High-temperature shrinkage, RR2
SRR2
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0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
S S S S S S S S T T T T T T T T WWWWWWWW X X X X X X X X
A B C D E F G H A B C D E F G H A B C D E F G H A B C D E F G H
Within-lab statistic, k
High-temperature shrinkage, RR2
SRR2
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0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
S T W X S T W X S T W X S T W X S T W X S T W X S T W X S T W X
A A A A B B B B C C C C D D D D E E E E F F F F G G G G H H H H
Within-lab statistic, k
High-temperature shrinkage, RR2
High-Temperature Thermal Insulation
• 4 thermal insulation round robins
– 5 to 7 labs
– Test method progressively refined
• 4 samples per round robin
• 4 replicates per sample
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Shrinkage & Thermal Insulation ILS Summaries
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ILS
No. of
Labs,
p
Materials
Average,
x avg
Repeatability
Std Dev,
s r
Reproducibility
Std Dev
s R
Repeatability
Limit,
r
Reproducibility
Limit,
R
Coefficient
of Variation,
CVavg
SRR1 7 S, T, W, X 0.050 0.0046 0.0062 0.0129 0.0172 9%SRR2 7 S, T, W, X 0.047 0.0038 0.0050 0.0108 0.0141 8%SRR4 6 R, U, V, Z 0.064 0.0044 0.0051 0.0124 0.0143 7%
TI1 7 S, T, W, X 51.4 1.62 3.75 4.55 10.49 3%TI2 6 S, T, W, X 54.7 3.88 5.77 10.87 16.17 5%TI4 5 R, U, V, Z 49.3 1.89 3.36 5.29 9.41 3%TI5 6 P50 17.7 0.18 0.92 0.50 2.58 1%TI5 5 P60 26.3 0.30 0.72 0.83 2.01 1%TI5 6 P64 27.9 0.54 0.72 1.50 2.03 2%TI5 6 P75 31.7 0.63 1.57 1.77 4.41 2%
High-Temperature Shrinkage
High-Temperature Thermal Insulation
Conclusions
• Core cohesion test very consistent.
• r&R determined for the high-temperature shrinkage & thermal insulation tests.
• All three test methods are practical for use in a plant quality assurance program.
• The largest source of uncertainty in predicting gypsum board performance in the ASTM E119 test was the E119 test itself, not the variability of the bench tests.
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