Synthetic Fiber Reinforcement for Concrete

摘要

Synthetic fibers are often added to concrete for crack control in concrete slabconstruction. The most widely available and used plastic fibers in construction are polypropylene and polyester. While polyester fibers are potentially susceptible to alkaline hydrolysis, no such adverse effects have been reported in the field. Suppliers recommend addition of 0.1 percent by volume for cracking control. At these levels, concrete strengths are only marginal ductility is observed during flexural loading. The fresh concrete slump is only slightly reduced, while the tendency for segregation and bleeding may be reduced. At these levels, the use of synthetic fibers prevents plastic shrinkage cracking in concrete slabs during placement. Adding the same amount of synthetic fiber may not control drying shrinkage cracking in the hardened slab. The use of synthetic fibers should not substitute for usual precautions for preventing this condition, nor should fibers replace welded wire fabric if shrinkage control joints will be spaced further apart than recommended for reinforced slabs. At current prices, using synthetic fiber reinforcement as secondary reinforcement in concrete slabs is cost effective compared to welded wire fabric when added at a level no greater than 0.1 percent by volume.... Concrete, Synthetic fibers, Fiber reinforcement.