Composite Bridge Decking: Phase I Design Report

APPENDIX L: FIRE TEST REPORT

Description of Tested Specimen

A full-depth panel measuring 3 feet by 7 feet was tested to evaluate its fire resistance properties. The standard design of the panel uses fire-resistant resin, but no further protection was provided. It was tested without a wearing surface. See figure 93.

Figure 93. Photo. Test panel mounted on top of fire chamber.

Description of Test Setup

The test specimen was placed over the pilot scale combustion chamber, resting atop and perpendicular to two structural steel support beams (I-beams) spaced 24 inches on center (to be consistent with the proof-of-concept bridge in Allegany County). The support beams each measured 10.5 inches high with 4-inch-wide flanges and 0.25-inch web thickness. The surrounding exposed areas were enclosed with 1-inch-thick non-combustible gypsum shaft liner panels. Only a portion of the length was exposed to the fire over the combustion chamber.

Figure 94 shows the fire test chamber and the steel beams used to support the deck. This picture was taken after the test; note the peeled paint above the fire chamber.

Figure 94. Photo. Support beams spaced at 2 feet.

The panel was loaded to a total superimposed load of 1,600 lb, nominally, using a water-filled steel tank, shown in figure 95, and instrumented with numerous thermocouples. Figure 96 and table 32 detail the placement of the thermocouples. The tank rested on the wood shown at the center of figure 93. This wood was dimensioned to reflect the standard AASHTO 10-inch by 20-inch footprint of a design vehicle.

Figure 95. Photo. 1,600-lb water tank used as concentrated load.

Figure 96. Photos. Placement of thermocouples on the test panel.

Table 32. Details of thermocouple placement.
Thermocouple	X, Y Location	Z Location
TC01	on longitudinal axis, 42" from transverse axis	top surface of deck panel
TC02	on longitudinal axis, 24" from transverse axis	top surface of deck panel
TC03	10" from longitudinal axis, on transverse axis	top surface of deck panel
TC04	10" from longitudinal axis, on transverse axis	top surface of deck panel
TC05	on longitudinal axis, 24" from transverse axis	top surface of deck panel
TC06	on longitudinal axis, 42" from transverse axis	top surface of deck panel
TC07	on longitudinal axis, on transverse axis	1-3/8" from top surface of deck panel
TC08	on longitudinal axis, on transverse axis	3-1/2" from top surface of deck panel
TC09	on longitudinal axis, on transverse axis	4-5/8" from top surface of deck panel

Test Program

The panel was loaded with the water tank before igniting the chamber and bringing the temperature to approximately 1,600 degrees Fahrenheit. The heat was applied for 20 minutes, at which time the test was stopped due to excessive smoke. Deflection measurements of the bridge deck panel, provided in table 33, were recorded at 1-minute intervals for the entire test duration. A technician sighted in on a leveling rod to measure the amount of deflection under load.

Table 33. Deflection measurements.
TC-797		BRIDGE COMPOSITES LLC					K-1084		9/7/2012
Time (min)	TC01	TC02	TC03	TC04	TC05	TC06	Grp Avg	TC07	TC08	TC09
0.00	76	76	76	76	76	77	76	77	76	78
0.25	77	76	76	76	76	77	76	77	76	78
0.50	76	76	76	76	76	77	76	77	76	78
0.75	76	76	76	76	76	77	76	79	76	77
1.00	76	76	76	76	76	77	76	82	76	78
1.25	76	76	76	76	76	77	76	87	76	78
1.50	76	76	76	76	76	77	76	95	76	77
1.75	76	76	76	76	76	77	76	104	76	78
2.00	76	76	76	76	76	77	76	125	77	78
2.25	76	76	76	76	76	77	76	137	77	78
2.50	76	76	76	76	76	77	76	147	77	77
2.75	76	76	76	76	76	77	76	157	78	78
3.00	76	76	76	76	76	77	76	165	79	78
3.50	76	76	76	76	76	77	76	174	80	78
3.75	76	76	76	76	76	77	76	182	81	78
4.00	76	76	76	76	76	77	76	189	82	78
4.25	76	76	76	76	76	77	76	197	83	78
4.50	76	76	76	76	76	77	76	204	85	78
4.75	76	76	76	76	76	77	76	211	87	78
5.00	76	76	76	76	76	77	76	218	89	78
5.25	76	76	76	76	76	77	76	225	91	78
5.50	76	76	76	76	76	77	76	233	93	78
5.75	76	76	76	76	76	77	76	239	94	78
6.00	76	76	76	76	76	77	76	240	96	78
6.25	76	76	76	76	76	77	76	239	98	78
6.50	76	76	76	76	76	77	76	240	100	78
6.75	76	76	76	76	76	77	76	242	102	78
7.00	76	76	76	76	76	77	76	245	103	78
7.25	76	76	76	76	76	77	77	248	105	78
7.50	76	76	76	76	76	77	77	251	106	78
7.75	76	76	76	76	76	77	77	254	108	77
8.00	76	76	76	76	76	77	77	258	110	78
8.25	76	76	76	76	76	77	77	261	112	79
8.50	76	76	76	76	76	77	77	266	114	79
8.75	76	76	76	76	76	77	77	270	115	79
9.00	76	76	76	76	76	77	77	274	117	79
9.25	76	76	76	76	76	77	77	278	118	79
9.50	76	76	76	76	76	77	77	282	120	79
9.75	76	76	76	76	76	77	77	286	121	79
10.00	76	76	76	76	76	77	77	291	123	79
10.25	76	76	76	76	76	77	78	295	125	79
10.50	76	76	76	76	76	77	78	299	126	79
10.75	76	76	76	76	76	77	78	303	128	79
11.00	76	76	76	76	76	77	78	307	131	79
11.25	76	76	76	76	76	77	78	311	132	80
11.50	76	76	76	76	76	77	78	316	133	80
11.75	76	76	76	76	76	77	78	320	136	80
12.00	76	76	76	76	76	77	78	325	138	80
12.25	76	76	76	76	76	77	78	331	139	80
12.50	76	76	76	76	76	77	79	337	140	80
12.75	76	76	76	76	76	77	79	342	140	80
13.00	76	76	76	76	76	77	79	348	144	80
13.25	76	76	76	76	76	77	79	354	146	81
13.50	76	76	76	76	76	77	79	360	148	81
13.75	76	76	76	76	76	77	79	365	150	81
14.00	76	76	76	76	76	77	79	369	152	81
14.25	76	76	76	76	76	77	80	374	154	81
14.50	76	76	76	76	76	77	80	379	156	82
14.75	76	76	76	76	76	77	80	384	158	82
15.00	76	76	76	76	76	77	80	389	159	82
15.25	76	76	76	76	76	77	80	395	161	82
15.50	76	76	76	76	76	77	80	401	164	83
15.75	76	76	76	76	76	77	80	407	167	83
16.00	76	76	76	76	76	77	80	413	168	83
16.25	76	76	76	76	76	77	81	420	171	83
16.50	76	76	76	76	76	77	81	427	172	84
16.75	76	76	76	76	76	77	81	432	174	84
17.00	76	76	76	76	76	77	81	438	177	84
17.25	76	76	76	76	76	77	81	443	179	84
17.50	76	76	76	76	76	77	82	448	180	84
17.75	76	76	76	76	76	77	82	453	181	84
18.00	76	76	76	76	76	77	82	458	185	85
18.25	76	76	76	76	76	77	82	463	187	85
18.50	76	76	76	76	76	77	82	467	189	85
18.75	76	76	76	76	76	77	83	473	191	86
19.00	76	76	76	76	76	77	83	477	194	86
19.25	76	76	76	76	76	77	83	481	196	87
19.50	76	76	76	76	76	77	83	484	197	87
19.75	76	76	76	76	76	77	76	488	200	88
20.00	86	83	87	87	82	78	84	493	203	89

At the end of the test, the panel was still carrying load and generally structurally sound, although the resin on the bottom had burned off, exposing glass fiber. The following photos illustrate the condition of the specimen afterwards.

Figure 97. Photo. The test panel just after the test stopped. Note that the top surface kept cooler and ended up with little deterioration.

Figure 98. Photo. Specimen immediately after the test. Note the extent of damage on the bottom.

Figure 99. Photo. Close-up of the open end of the panel after the test.

Figure 100. Photo. The glass fiber on the bottom has frayed due to burn-off of the resin matrix.

Results

The deck panel survived 1,600-degree Fahrenheit temperatures relatively well. The top surface did not rise much higher than room temperature (~80 degrees Fahrenheit). Although the bottom surface suffered extensive damage, the multi-celled structure protected the upper part and reduced the spread of flame and high temperatures. The panel carried the full 1,600 lb. superimposed load with a maximum deflection of 5/16 inches. There was no crushing of the tubes observed, no excessive bending, and the panel was still functional at the end of the test.