Experimental Study of Strength and Durability Properties of Hybrid Fiber Reinforced Concrete of M25 Grade

Among all the construction materials that are available for construction, we know that concrete is a widely used construction material for building of various civil engineering structures. Concrete will give better durability and also its costs during construction as well as maintenance are very low when compared to other construction materials. As we know that concrete is strong in construction and weak in tension and tends to fail because of its deficiencies such as low tensile strength, low strain at fracture. The weakness of concrete is due to the presence of micro cracks at mortar aggregate interface. To overcome the existing problems addition of fibers in the concrete has been come in to practice. In fiber reinforced concrete the fibers are added to the concrete mix so that those are discontinuous fibers will be uniformly distributed in the mix and improve the concrete properties in all directions. To get more improvement in the mechanical properties work has been done by combining two different types of fibers knows as hybridization. In present experimental work for M25 grade of concrete can be designed according to IS 10262:2009 with four different proportions of hybrid fibers are added with concrete ingredients. The proportion of steel and polypropylene fibers are added by 50% each with different hybridization ration i.e. 0%,0.5%, 1.0 %, 1.5% and steel fibers are added by volume of concrete and polypropylene is added by weight of cement. For strength parameters compressive, tensile, flexural, impact strength specimens are casted and cured for 28 days and tested for hardened concrete and for fresh concrete slump and compaction factor test is carried to know the workability of hybrid fiber reinforced concrete. For durability study Sorptivity test is carried out to know the absorption of water by capillary. To evaluate the strength parameters different tests are conducted and results are tabulated. From the present work results show that 1.5 % addition of hybrid fiber gives maximum results in all the strength parameters compare to other different hybrid ratios.