Applications of bolted steel plates to shear strengthening of RC beams

I Ketut Sudarsana,I Gusti Ngurah Oka Suputra,I Putu Chandra Sajana,M Olivia,M Infantri Yekti,G Pringgana,G Wibisono,R Ridwan,D Andrio,D Wishart,A Marto,E Saputra,K Yamamoto,I.D Ketut Sudarsana,I.M Agus Ariawan

doi:10.1051/matecconf/201927601002

Abstract

Many reinforced concrete beams have been found deficiencies in shear due to lack of shear reinforcement. Few researches have been done to investigate shear strengthening of low concrete strength of RC beams using bolted steel plates. This paper presents experimental results on the behaviour of RC beams strengthening using full steel plates along the shear span fixed with bolts. Nine RC beams having dimension of 150x200x1500mm were tested to failure on simply supports with four point loadings setup. The beams were reinforced with tension rebars area of 289.8 mm2 (2D10+1D13) and transvers reinforcement of Ø6-125. Two dial gauges were installed at the beam middle span to measure beam deflection during the test. The results show that the applications of steel plate and bolts as external reinforcement increase beam shear capacity, stiffness and delay the occurrence of first diagonal cracks. Beams stregnthened with U-shape plates gave better performances than the beams with two pieces of L-shape plates due to better achorages.

Highlights

Shear failure of RC beams is a brittle failure without significant warning that has to be avoided in RC structural design
Adhikary et al [3] showed that the increase in beam shear capacity of RC beams with continuous steel plates bonded externally to beam webs is a function of plate thickness and plate depth
The of K is based on statistical analysis of 554 data by [4] as follows : κ where, ρv is the shear reinforcement ratio, tp is the thickness of the plates at both sides of the beam web, hp is the depth of the steel plates across the section, h is the height of the beam, bw is the beam‘s width, fyp is the uniaxial yield strength of steel plate and f’c is the compressive concrete strength

Summary

Introduction

Shear failure of RC beams is a brittle failure without significant warning that has to be avoided in RC structural design. Barnes and Mays [5] investigated the shear strength of plated RC beams subject to different shear failure modes, and a design method for RC beams strengthened with continuous external steel side plates was proposed [6]. In the same year, [2,4] studied various shear strengthening techniques with some parameters of bonded steel plates to RC beam webs and the proposed formula to calculate the shear contribution of the steel plates. The shear capacity of the steel plated RC beams can be calculated as a combination of the contribution from concrete (Vc), internal shear reinforcement (Vs) and external bolted steel plates (Vp). Where, ρv is the shear reinforcement ratio, tp is the thickness of the plates at both sides of the beam web, hp is the depth of the steel plates across the section, h is the height of the beam, bw is the beam‘s width, fyp is the uniaxial yield strength of steel plate and f’c is the compressive concrete strength

Material properties

RC beam specimens

Test setup and instrumentations

Crack pattern and failure modes

Beam capacities

Conclusions