Concrete for Tunnel Liners:Evaluation of Fiber Reinforced Quick Setting Cement Concrete.

摘要

This study was undertaken to determine the behavior of steel fiber reinforced,quick setting cement concretes and provide information on this material needed for its application in tunnel linears. Strength-time and creep behavior are evaluated for specific mix designs. Interaction diagrams are presented for concretes made with Duracal cement and fiber contents of 0.9, 1.2and 1.5percent by volume. Tensile stress-strain relationships are analytically obtained from flexural test data. These relationships make possible a post-crack analysis of a fiber reinforced concrete structure. Fiber content,fiber orientation,and type of cement have little affect on Poisson's ratio but do influence the modulus of elasticity and the strength. Pumping of fibrous concrete is investigated through laboratory testing. The presence of fibrous reinforcement significantly increases the volume of voids making the aggregate gradation and cement paste content critical parameters in designing pumpable mixes.