Investigation of Properties of Fiber Reinforced Concrete Using Rubber Tyre Tube Wastage as Fibers

Author Name(s): Akshay Shirpurkar, Sumit S. Geete
Author Email: sumit.geete@gmail.com

Abstract

Fiber reinforced concrete (FRC) is widely used as construction material. Fibers increase the structural integrity of concrete. Steel fibers, glass fibers, synthetic fibers and natural fibers are types of fibers used in FRC. Waste deposition of vehicles tyre after its useful life became critical issue to dispose off. In the present study preliminary investigation is carried out to check the feasibility of waste tyre tube material as fiber material in concrete. Waste tyre tube collected from different sources and cutting to aspect ratio 40 and called Rubber Tyre Tube Fiber (RTTF). Dose of RTTF is decided from the literature pertaining to FRC as 0.5%, 1.00% and 1.5% with respect to volume of concrete. Fresh and hardened properties of concrete are investigated with utilization of RTTF as fiber. Hardened state performance of RTTF reinforced concrete improved over the control mix. RTTF reinforced concrete is more crack resistance than control mix. Flow ability or workability of the concrete decrease with increment of dose of RTTF fiber because of formation of flocks. These flocks in the fresh concrete decrease the workability of concrete.

Introduction

Fiber reinforced concrete (FRC) is a composite material made with Portland cement, aggregate, admixture and incorporating discrete discontinuous Fibers. Plain, unreinforced concrete is a brittle material, with a low tensile strength and a low strain capacity. Randomly distributed fibers in concrete bridge the propagation of crack and minimize the increment in the width of crack. Fibers in the concrete are increases strain carrying capacity of concrete. The main purpose of adding any of Fiber types to concrete is not to prevent cracking but to control it. Steel and polypropylene fibers two mains types of fibers used in worldwide. The recommended dose of the fibers lies in the range of 20-40kg/m3 or 0.25-1.5% by volume of the concrete. As the dose of fiber in the concrete increases then flexural strength of concrete also increases [11]. Inclusion of fibers in the concrete reduced the workability of the concrete. Fibers impart heterogeneity to the FRC. Addition of polypropylene fibers to the concrete is responsible for the balling effect and reduction of the slump. The inclusion of the Fibers into the concrete mix influences its workability, with increasing in the Fiber volume and aspect ratio leading to decreased workability (Hannat, 1978; Swamy, 1974). Fibers are used super plasticizers to minimize the slump reduction of concrete. Fibers delay and control of tensile cracking of FRC.

Conclusion

Based on the preliminary experimental investigation, it is concluded that addition of RTTF improved the hardened properties of concrete i.e. compressive strength, split tensile strength and flexural strength. RTTF could be use as fiber in fiber reinforced concrete. Addition of RTTF to the concrete reduced the workability of concrete because of balling effect. To counterbalance this balling effect, it is necessary to use the plasticizers or super plasticizer. Again it is necessary to study stress-strain behaviour of the RTTF concrete with load deflection curve.

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