MECHANICAL PROPERTIES AND DURABILITY OF HIGH-STRENGTH CONCRETE FOR PRESTRESSED BRIDGE GIRDERS

Results from a comprehensive laboratory investigation on the application of high-strength concrete to the production of precast/prestressed bridge girders are presented. The portion of the laboratory investigation described consisted of producing high-strength concrete with a variety of cementitious materials (portland cement, silica fume, and fly ash) in different proportions and made with five different types of coarse aggregate. Some specimens were moist cured in saturated-limewater at 23 deg C; others were heat cured in an environmental chamber at 65 deg C to simulate the accelerated curing technique typically used by precast/prestressed plants. The hardened concrete specimens were tested for compressive strength, modulus of elasticity, tensile strength, modulus of rupture, shrinkage, creep, absorption potential (as an indirect indicator of permeability), and freeze-thaw durability.