Verification of selected calculation methods regarding shear strength in beams without web reinforcement

Marta Hirsz,Krystyna Nagrodzka-Godycka,Elżbieta Urbańska-Galewska

doi:10.1051/matecconf/201821903015

Marta Hirsz, Krystyna Nagrodzka-Godycka + Show 1 more

Open Access

https://doi.org/10.1051/matecconf/201821903015

Copy DOI

Abstract

The purpose of the article was to compare selected calculation methods regarding shear strength in reinforced concrete beams without web reinforcement. Several calculation methods were tested. This included codes: PN-EN 1992-1-1:2008, ACI 318-14 andfibModel Code for Concrete Structures 2010. The analysis also consists of authorial methods published in technical literature. Calculations of shear strengths were made based on experimental works found in literature. The shear strength ratios Vtest/Vcalcwere chosen to be the yardstick of comparison, where Vtestis the experimental shear strength and Vcalcis the calculated shear strength. A wide range of variables including shear span/depth ratio, compressive strength of concrete, longitudinal steel percentage helped to verify the applicability of calculation methods. Although most of authorial techniques proved to be unstable, they succeeded to show that codes’ formulas for shear strength may still be improved. The presented article is a part of Authors’ long term research in the matter and a new chapter of their study now concerning beams without web reinforcement.

Highlights

Over the years much research and many debates have taken place all around the world to better understand the shear mechanism in beams both with and without web reinforcement [1, 2]
Many experiments and analysis have been carried out, the provisions regarding calculating shear strength provide results that often differ from experimental data [3, 4, 5]
As it was prior proved by the Authors in the context of reinforced and prestressed concrete beams with shear reinforcement [6], the understanding of stress distribution in the support zone is still to be improved

Summary

Introduction

Over the years much research and many debates have taken place all around the world to better understand the shear mechanism in beams both with and without web reinforcement [1, 2]. Many experiments and analysis have been carried out, the provisions regarding calculating shear strength provide results that often differ from experimental data [3, 4, 5]. As it was prior proved by the Authors in the context of reinforced and prestressed concrete beams with shear reinforcement [6], the understanding of stress distribution in the support zone is still to be improved. The reliability of most calculation methods was undeniable, economics was lacking Is this observation valid for beams without shear reinforcement?. - longitudinal reinforcement was either steel or GFRP bars, - all cross sections were either rectangular or T-beams, - all beams failed in shear, - all beams were single – span, - no limitation on material properties was imposed, - beams with fiber - reinforced concrete were excluded from the analysis, - in order to compare analytical results with experimental data, all units were taken without reduction factors.

Objectives

Methods

Conclusion