Shear in high strength concrete bridge girders : technical report.
-
2013-04-01
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:Prestressed Concrete (PC) I-girders are used extensively as the primary superstructure components in Texas highway bridges.
A simple semi-empirical equation was developed at the University of Houston (UH) to predict the shear strength of PC I-girders
with normal strength concrete through the project TxDOT 0-4759. The UH-developed equation is a function of shear span to
effective depth ratio, concrete strength, web area and amount of transverse steel. This report intends to (1) validate the UHdeveloped
equation for high strength concrete by testing ten 25-feet long full-scale PC I-girders with different concrete strength.
(2) validate the UH-developed equation for different sizes of PC girders and studying the possibility of having premature failure
due to local failure in end zone.
Ten modified Tx28 PC girders were tested for the first objective. The girders were divided into three groups (namely Groups
A, C and F) based on the concrete compressive strength. Group A consisted of two girders with a concrete compressive strength
of 7000 psi. Group F had four girders with a concrete compressive strength of 13000 psi and Group C included four girders with
a compressive strength 16,000 psi. Girders in Group A were designed to have a balanced condition in shear. A pair of girders
each belonging to Group F and Group C were designed to have a balanced condition while remaining girders were designed as
over-reinforced sections. Each group of the PC girders was tested with different shear span to effective depth ratio so as to get
two types of shear failure modes, i.e., web-shear and flexure-shear. The validity of the proposed UH-developed equation was
ascertained using the girders test results. UH-developed equation was found to accurately predict the ultimate shear strength of
PC girders having concrete strength up to 17,000 psi with enough ductility.
Six PC girders of Tx-series with three different sizes were tested for the second objective. The girders were divided into three
groups (namely Groups D, E and G) based on the girder depth. The test data shows that the PC girders of the new Tx-series has
no cracks under service loads and can reach the maximum shear capacity without having a shear bond failure. Also, these
girders’ test results ensured the validity of the UH-developed equations for PC girders with different sizes.
Simulation of Concrete Structures (SCS), a finite element program recently developed at UH, was used to predict the shear
behavior of the tested girders. Analytical results presented in this report proved the validity of SCS to predict the behavior of PC
girders with different concrete strength up to 17,000 psi and with different depth up to 70 inches.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
File Type:
Supporting Files
-
No Additional Files
More +