Formulation of Prediction Models for Mechanical Properties of Steel Fibre Reinforced Concrete

Abstract

Concrete plays a major role in the construction industry. Introducing fibres in the concrete will improve the mechanical properties and are responsible for the bridging the cracks. Concrete is brittle because of high compressive strength and low tensile strength. Incorporation of fibres improves the brittleness of concrete. Fibres also resist the load even after cracking and thus it enhances the post crack performance. The objective of the study is to determine the mechanical strength properties such as compressive strength, splitting tensile strength and flexural strength of the concrete reinforced with steel fibres in various volume fractions, to predict the strength model equations using multiple regression analysis and to compare the predicted equations with the prevailing strength models from various literatures. In this study, a control mix and 12 different mixes were produced with the target compressive strength of 60 MPa. Steel fibres with lengths of 30, 36 and 50 mm were used and they were introduced in the volume of fractions of 0.25, 0.35, 0.5 and 0.75%. The prediction equations for the mechanical strength properties were developed considering concrete compressive strength, Fibre Volume fraction (FV_f) and Fibre Reinforcing Index (FRI) as the parameters. The developed strength models were then compared with the other prevailing models from the literature based on the statistical parameters such as Average Absolute Error (AAE) and Mean Squared Error (MSE). From the investigation, it was found that the proposed strength equations provided more accurate and better results.