In the past several years, an increasing number of contractors have placed concrete containing polypropylene fibers. Fiber manufacturers have promoted the material as a practical alternative to the use of welded wire fabric for control of shrinkage and temperature cracking. This article reviews some of the suggested applications for concrete reinforced with fibers and surveys recent studies concerning properties of the fiber-reinforced concrete. The major conclusions are:
- Adding fibers reduces the slump of concrete. There appears to be less plastic shrinkage and less plastic shrinkage cracking when concrete contains polypropylene fibers.
- Drying shrinkage after hardening is reduced when fibers are added to concrete but the amount of the reduction is difficult to predict using current testing methods.
- Some increase in compressive and flexural strength is possible when fibers are added to concrete and an increase in fatigue resistance has been noted by one researcher.
- Results of two abrasion resistance studies are contradictory and there aren't enough test results to permit drawing a conclusion. There is also insufficient data concerning impact resistance.