Impact of high volume GGBS replacement and steel bar length on flexural behaviour of reinforced concrete beams

Zainab S Al-Khafaji,Ali A Shubbar,Ali Al-Rifaie,Rafal Latif Al-Mufti,Mohammed Salah Nasr,Abdullah Alkhulaifi,Ali Majdi,Shahad F Al-Mamoori,Ahmed Alkhayyat,Khalid Hashim

doi:10.1088/1757-899x/1090/1/012015

Abstract

The Ordinary Portland Cement (OPC) is one of the major ingredient utilized for the manufacture of concrete. The manufacturing of cement includes the release of huge amounts of CO2 gas as a main contributor for greenhouse influence and global warming. Several researchers have investigated the characteristics of OPC concrete utilizing cementitious materials like fly ash, silica fume, and Ground Granulated Blast furnace Slag (GGBS) as replacement materials. The article aims to investigate experimentally the flexural behavior of concrete beams with GGBS. The experimental work was divided into three stages, the first one consists of six reinforced concrete beam specimens with (0%, 40% and 60%) of GGBS. During this stage, the used steel bars were 8 mm diameter and 500 mm in length. In the second stage, the length of the steel bars was reduced to 400 mm with the best mixture of (GGBS+OPC) that obtained from stage 1. In the third stage, the best length of steel bars was used with the best (GGBS+OPC) ratio to be tested at 7, 14 and 28 days from the date of casting. Consequences of this exploration suggests that replacement of OPC with 40 percent GGBS with 500 mm steel bar length can be used in reinforced concrete specimens as it shows comparable results relative to control mixtures (0% GGBS).

Highlights

Concrete is a necessary material utilized in the Building field [1,2], and as the construction is growing quickly around the globe, the demand for concrete is increasing along with it [3,4]
The experimental work was divided into three stages, the first one consists of six reinforced concrete beam specimens with (0%, 40% and 60%) of Ground Granulated Blast furnace Slag (GGBS)
Consequences of this exploration suggests that replacement of Ordinary Portland Cement (OPC) with 40 percent GGBS with 500 mm steel bar length can be used in reinforced concrete specimens as it shows comparable results relative to control mixtures (0% GGBS)

Summary

Introduction

Concrete is a necessary material utilized in the Building field [1,2], and as the construction is growing quickly around the globe, the demand for concrete is increasing along with it [3,4]. Governments and companies in the cement industry has become aware of the negative effects and drawbacks of the usage of the OPC on the environment such as the carbon dioxide (CO2) emissions [7,8,9,10,11]. Approximately 7 % of the emissions of the CO2 is attributed to the cement industry [12,13,14,15]. To preserve the environment, CO2 emissions must be reduced [16] This led the industry and researchers to investigate suitable replacement to the OPC to decrease this negative influence on the environment [8]. Cementitious waste and/or by-products materials including Meta-kaolin [17], rice husk ash [18], Ground granulated blast furnace slag (GGBS) [19], silica fume [20,21,22,23,24,25], fly ash [26], waste paper [27], stainless steel powder [28], etc., have been utilized as a replacement to OPC

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Conclusion