EXPERIMENTAL INVESTIGATION OF FIBER REINFORCED SELF COMPACTING CONCRETE
Abstract
Self compacting concrete (SCC) is a special type of concrete that can flow and compact under its own weight. Due to its excellent deformable and segregation resistance property, full compaction can be achieved without vibration in form works with heavy and congested reinforcement and at the same time it is cohesive enough to be handled without segregation. Fibers are added to enhance its ductility, toughness, tensile strength and to reduce drying shrinkage. In this experimental work a simple mix design method viz NAN SU method is followed to proportionate the mix design of self compacting concrete (SCC) of grade M50 and M60. At the same time, it should satisfy the EFNORC guidelines for the workability at fresh state and strength requirement at hardened state. Two SCC mixes have been developed with GGBS as mineral admixture and recron 3s and glass fibers separately. These recron 3s and glass fibers are added to M50 and M60 grades in deferent percentages like 0.25%,0.5%,0.75% fresh FRSCC separately by volume of binder and then fresh and hardened properties of the resultant mixes have been studied.
Tests have been carried out on cubes and cylinders of SCC with and without addition of Fibers to find out compressive and split tensile strengths. The volume and length of fibers combined with cementanious material in the mix influences the flow properties of wet mix. To identify this, recron 3s and glass fibers of length 12 mm and diameter 30 microns in dosages varying from 0.25% to 0.75% by volume of the binder were added. Due to the influence of maximum fiber factor unacceptable results for workability of fresh mix due to a phenomenon such as blockage of spaces through the vertical bars of L-Box is predicted. So, to reduce this, the fibers of length and dosage not more than 12 mm and 0.75% by volume of binder respectively may be used to satisfy the EFNARC workability requirements of fresh concrete. The compressive strength of SCC is found to be more or less constant whereas, the split tensile strength increases with increase in fiber content.
