Evolution of HPC Specifications in Texas

This paper describes how the Texas Department of Transportation (TxDOT) specifications for high performance concrete (HPC) have evolved through TxDOT’s experience. The first two HPC projects in Texas in the 1990s were guided by researchers at the University of Texas, Austin, in conjunction with demonstration projects sponsored by the Federal Highway Administration (FHWA). Although these two projects focused on high-strength HPC, the cast-in-place concrete deck on one of the two adjacent bridges in each project was constructed with normal strength HPC. Concrete strengths of 9000 psi (62 MPa) and higher with good durability characteristics are readily achieved in pretensioned concrete beams in Texas. Now, the priority in Texas is to improve the durability of normal strength cast-in-place concrete. Therefore, subsequent HPC bridge projects have focused on normal strength cast-in-place HPC. This paper discusses activities that address this priority.