Durability and Physical Properties of Steel Fiber Reinforced Concrete.

摘要

The durability and physical properties of steel fiber reinforced concretes proportioned for pumpability criteria for tunnel liners are reported. The mix parameters include fiber contents of 0.9, 1.2and 1.5volume percent,maximum aggregate sizes of 3/8, 1/2, 3/4and 1in. (10, 13, 20and 25mm),and use of water reducers. Tests were performed at 28 d with type 1cement concrete and between 1-1/2 h and 90 d with regulated-set cement concrete. Regulated-set cement concrete is found to lose nearly twice the strength as type 1cement concrete for exposure to 660 F (350 C). Corrosion of steel fiber reinforcement is observed in cracked concrete with no apparent lower bound on crack size. The magnitude of the shrinkage of portland cement concretes proportioned for pumpability is related to the high paste contents required to fill the voids in the aggregate fiber array. An estimate of shrinkage can be made if the proportions of the mix and the curing are known.