Investigations into Synthetic Fibre Reinforced Concrete Beams

Abstract

Fibre is a small piece of reinforcing material described by a numerical parameter, called aspect ratio which is the ratio of its length to its equivalent diameter (l/d). In the Biblical period Romans introduced the concept of “Fibres” in the building material by using the “HORSE HAIR” as the fibrous material and since then the use of fibres was incorporated. Recently, however, the development of Fibre Reinforced Concrete (FRC) in various fields has provided a technical basis for improving the deficiencies in mortar and concretes. At hydration stage, water tends to escape through various routes and cracks develop on the surface. These leads to water penetration resulting in dampness and need repainting of walls and other repair. The aim of the present experimental investigation is to study the effect of addition of synthetic fibres on the ultimate strength and behavior of the concrete and mortar. The fibre content (by volume) is the main parameter considered in the study. A combination of a low ratio of conventional fibre reinforcement together with synthetic fibers may provide a practical solution, increasing the strength of the beams without causing congestion of the reinforcement. Fibres in the concrete act as crack arresters and considerably enhance the ductility. In the investigation a total of 240 full-scale specimens with and without fibre contents were casted, and tested to failure under symmetrically applied loads. The fibres volume Vf is vary from 0% to 1.5%. As the test was in progress, the development and propagation of cracks, the load at first crack and the mode of failure was noted. The results were compared to control sample and the viability of adding synthetic fibre to concrete and mortar was verified.