Mechanical and durability properties of hybrid fiber reinforced foam concrete

Abstract

Foam concrete is a light-weight concrete which consists of cement, filler, water and foaming agent. Despite the many advantages of foam concrete, its main disadvantages are lower strength & shrinkage. Shrinkage can be reduced by the effective use of natural fibers while in order to increase strength, synthetic fibers have a vital role. The addition of an optimum hybrid combination of synthetic and natural fibers in foam concrete can enhance its strength and make it more durable. This paper describes the study of mechanical, durability and functional characteristics of hybrid fiber reinforced foam concrete (HFRFC). The cement to filler ratio used in this study is 1:1, with the sand being completely replaced with bottom ash. The targeted design densities of all the specimens were 1600 kg/m3. Poly vinyl alcohol (PVA) fiber and coir fiber with volume fraction 0.3%, 0.4% and 0.5% were added. The hybrid combinations were designed such that to get total volume of fibers as 0.3%, 0.4% and 0.5%. From the investigations, it is inferred that the optimum percentage of fibers to get the maximum strength is 0.3% for both PVA and coir. In hybrid combinations, the strength is satisfactory without much reduction. The durability properties increased for all hybrid combinations. Thus, the hybrid fibers can be a solution to improve strength, functional characteristics and durability of light-weight foam concrete.