Compressive strength and microstructure of Self Compacting Concrete with nylon fiber substitution

Concrete is the most widely used construction material as building material because it has advantages such as easy workability, high compressive strength, and economical in terms of manufacturing and maintenance. However, there are some disadvantages obtained from the use of concrete, such as low tensile strength, easy cracking, and brittleness. Therefore, it is necessary to add fiber to the concrete to increase the ductility and use of SCC concrete to maintain workability after fiber substitution. The variation in the addition of nylon fiber is 0.5% and 1% to the weight of cement with a diameter of 0.35 mm and 0.65 mm, a length of 15 mm, and 20 mm. With the addition of 1% of 0.65 mm diameter and 15 mm length, the compressive strength of SCC concrete increased by 126%. The nylon fiber was also found to be evenly distributed in the concrete mixture and did not experience clumping and the volume weight of the concrete was reduced by 5-7% of the normal concrete. The SEM results show a clear interface between concrete and nylon fiber, and the slippery morphology of nylon fiber causes the bonding with concrete to become weak.