Transfer and Development Lengths of Fully Bonded 1/2-Inch Prestressing Strand in Standard AASHTO Type I Pretensioned High Performance Lightweight Concrete (HPLC) Beams

The use of high performance lightweight concrete in Texas highway bridges could lead to a significant reduction in the dead load. Compressive strengths of 6,000 – 8,000 psi (41.4 – 55.2 MPa) can be achieved while maintaining a unit weight of 120 lb/ft3 (18.9 kN/m3). The behavior of ½-in (12.7-mm) prestressing strand in Standard AASHTO Type I beams is necessary to determine the feasibility of these HPLC bridges. Specimens were tested for transfer length, which indicated that ACI and AASHTO equations for the transfer length were not conservative for the HPLC. Development length testing indicated that the ACI and AASHTO equations for this value are conservative for the HPLC. The flexural behavior of the composite beams was similar to normal weight concrete beams tested.