Lightweight Concrete for High Strength - Expanded Shale & Clay

Appendix C. Girder Construction and Testing
This appendix presents further details of the girder design, construction, and testing.
C.1 Composite Girder Design Procedure
Three each Series G1 girders and three each Series G2 girders were designed with
concrete design strengths, f c ’, of 8,000 psi and 10,000 psi, respectively. Based on previous
experiences, it was assumed the girder lengths would be in the range of 35-45 feet. Final design
lengths were revised to accommodate the tests as needed. Three tests were planned for each of
the six girders indicating 18 total tests. Since two concrete strengths were being investigated,
there were 9 different test configurations that were performed on each series of girders. The
prestressed girder design spreadsheet was used to iteratively design the tests to fit on the girders.
The resulting tests were detailed in Table C.1. The a/d ratio listed under “Point Load Placement
Criteria” is the shear span to depth ratio where “d” is the total height of the composite girder.
Test
Configuration
Stirrup
Density
Table C.1 – Girder Test Configurations
Point Load
Placement
Criteria
Shear
Span
“a”
(inches)
Distance
“L 1 ”
Distance
“L 2 ”
Distance
“L”
(inches) (inches) (inches)
1 Single l d 90 456 0 456
2 Double 0.70*l d 61 316 0 456
3 Double 0.85*l d 75 456 0 456
4 Single 0.95*l d 85 504 0 504
5 Single 0.70*l d 61 321 0 456
6 Single 0.85*l d 75 369 0 504
7 Minimum a/d=2.28 82 185 140 456
8 Minimum a/d=2.67 96 210 135 456
9 Minimum a/d=3.33 120 244 135 504
d = 47.5 inches
The dimension “a” was the shear span. The dimension L 1 was the distance from the left
support to the right support. The dimension L 2 was the distance from the left COB to the left
support. The COB was the point at a distance of 6 inches in from each girder-end that was
assumed to be the girder’s support point for curing. L 2 was used to signify a cantilever on the
C-1