Composite Bridge Decking, Final Project Report

3. DECK FABRICATION

This section describes the materials and methods used to fabricate deck panels. The fabrication method is flexible enough that various support spans can be accommodated with a slight modification of the panel structure; however, all variations are based on a standard pultrusion that serves as a building block for the deck.

Materials

Resin

The resin used is a fire-resistant vinyl ester resin from Ashland Chemical called Derakane 510C.

Fiber

See tables 2 and 3 for detailed descriptions of the fiber layers. The reinforcement is E-glass rovings, woven mat, and chopped strand mat (CSM) from PPG and Owens-Corning. Glass from other manufacturers could be used as well. The individual ply details of the laminate constructions for the horizontal and vertical walls also are given in the tables.

Table 2. Ply details for horizontal walls of pultruded tube.

Material	Angle (°)	Areal Weight (oz/yd2)	Thickness (in.)
1 ½ oz CSM	n/a	1.5	0.016
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
Roving - 3.7 ends/in.	0	38.3	0.038
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
Roving - 3.7 ends/in.	0	38.3	0.038
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
1 ½ oz CSM	n/a	1.5	0.016
TOTALS	0	76.6	0.204
	90	34.6
	+45/-45	37.6
	CSM	27.3

Table 3. Ply details for inclined walls of pultruded tube.

Material	Angle (°)	Areal Weight (oz/yd2)	Thickness (in.)
1 ½ oz CSM	n/a	1.5	0.017
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
Roving – 7.6 ends/in.	0	78.6	0.078
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
E-TTXM 2308	45	6.27	0.032
	90	11.52
	-45	6.27
	CSM	8.10
1 ½ oz CSM	n/a	1.5	0.017
TOTALS	0	78.6	0.240
	90	46.1
	+45/-45	50.2
	CSM	27.3

Composite Materials

Table 4 provides details of the material properties of the composite material.

Table 4. Material properties of composite material.

Laminate Unit Value	Unit	Values for Horizontal Walls Thickness = 0.20 in.	Values for Inclined Walls Thickness = 0.24 in.
Elastic modulus of 0 degree, Ex	psi	3.39 E+6	3.18 E+6
Elastic modulus of 90 degree, Ey	psi	2.33 E+6	2.39 E+6
Shear modulus, Gxy	psi	0.74 E+6	0.75 E+6
Ultimate tensile strength of 0 degree	psi	63,600	55,600
Ultimate tensile strength of 90 degree	psi	20,600	22,300
Ultimate compressive strength of 0 degree	psi	54,800	51,600
Ultimate compressive strength of 90 degree	psi	22,300	23,600
Ultimate shear strength	psi	8,000	8,600
Poisson’s ratio	-	0.27	0.27

Grout

The grout selected was epoxy based. This is used to add compressive strength to tube sections and is used for field joints. Properties are shown in table 5.

Table 5. Material properties of polymer grout.

Properties	Unit	Value
Compressive strength	psi	1.32E+4
Tensile strength	psi	2.35E+3
Elastic modulus	psi	2.16E+6

Tubes

A basic building block of the deck is the trapezoid-shaped pultrusion. It is a three-cavity trapezoid, as shown in figure 1. Figure 2 shows the standard dimensions, and figure 3 provides details regarding the fiber architecture.

Panel Fabrication Methods

Figures 4 through 11 illustrate the steps for assembling the deck panels.