Flexural behaviour of hybrid fibre reinforced concrete beams made with various packing factors and fine to total aggregate ratio

V Siva Prasad Raju,Gorla Jayasri,A Naga Sai Baba,V Srinivasa Reddy,S Tummala,S Kosaraju,S Singh,P Bobba

doi:10.1051/e3sconf/202130901060

Abstract

The objective of this study is to investigate the flexural behavior of M30 grade PSCC, GFRSCC, SFRSCC and HFRSCC beams made with PF=1.12 and s/a=0.53 and PF=1.14 and s/a=0.57 to understand the effect of copper slag as partial replacement of fine aggregate on its deflection characteristics and cracking behaviour. The yield and ultimate load taken by HFRSCC beams made with optimum PF and s/a ratios are higher than the conventional RCC beam elements. The deflections at centre at failure in HFRSCC beams made with optimum PF and s/a ratios were more than that of conventional beams. This shows improvement in ductility of HFRSCC beams. First crack formation was delayed in M30 grade HFRSCC beams due to dense micro structure with low pore fraction and reduced pore size due to which fatigue strength is increased which in turn increases the time taken for first crack occurrence and thereby increasing the load carrying capacity. The deflection at the mid span decreased in HFRSCC beams which shows that the flexural stiffness of the elements increases thereby reducing the structural member’s deformability, increasing strength and hence controlling deflection.

Highlights

Self-Compacting concrete, originally developed in Japan has given answers to many mechanical and durability problems and enhanced the strength and durability characteristics of concrete
The goal of this research is to look at the flexural behaviour of M30 grade PSCC, GFRSCC, SFRSCC, and HFRSCC beams with packing factors (PF)=1.12 and s/a=0.53 and PF=1.14 and s/a=0.57 to see how copper slag as a partial substitute for fine aggregate affects deflection and cracking behaviour
Flexural parameters such as load at first crack, ultimate flexural strength, deflection at the centre, and crack width at failure are assessed using load– deflection plots. From these obtained results the following observations are made: 1. The yield and ultimate load taken by HFRSCC beams made with optimum PF and s/a ratios are higher than the conventional RCC beam elements

Summary

Introduction

Self-Compacting concrete, originally developed in Japan has given answers to many mechanical and durability problems and enhanced the strength and durability characteristics of concrete. Introduction of fibers in SCC has further improved its characteristics like crack, resistance, plasticity, impact resistance, durability etc., The Studies on Stress-Strain behavior of concrete are essential in determining the parameters like energy absorption, toughness, plasticity index and they are very useful in design of structures using such concretes. Further modeling the stress-strain behavior helps in predicating their behavior. As only scant work is reported on the mathematical modeling of the stress strain behavior SCC and f FRSCC, an attempt is made to make M30 grade SCC, FRSCC, developed two mathematical models for stress-strain behavior after going thoroughly through different models for stress- strain behavior developed for vibrated concrete. The two models were compared for their suitability for SCC and FRSCC

Objectives

Methods

Conclusion