Shrinkage and impact resistance of high strength concrete with polypropylene fibers

الملخص EN

Current trends in construction projects require the use of high strength concrete.

Achieving such task mandates the use of proportionally high cement content, which comes with a band of problems such as high rate of plastic shrinkage and rapid development of micro-cracks.

TheB focus of the present investigation is the differences in mechanical properties of high-strength concrete and ordinary strength concrete and the effect of using polypropylene fibers in the manufacturing of high-strength concrete.

Three mixtures of concrete were cast to be representative of ordinary concrete, high strength concrete with and without polypropylene fibers.

The samples were tested for compressive strength at 7, 28 and 90 days and splitting tensile strength at 7 and 28 days.

Plastic shrinkage was monitored for 24 hours immediately after casting and impact resistance was determined after 28 days.

The results indicate that high strength concrete with and without polypropylene fibers has better mechanical properties than ordinary concrete especially for compressive strength, tensile strength and impact.

The plastic shrinkage for high strength without polypropylene fibers was higher than that of ordinary concrete.

The study signifies that using polypropylene fibers can improve plastic shrinkage and reduce the formation of micro-cracking of high strength concrete.

Moreover, the fibers significantly improve concrete impact resistance.