Mechanical Properties of Geopolymer Concrete Exposed to Combustion

Annisa Rahmadina,Januarti Jaya Ekaputri,J.-W Park,H Hardjasaputra,H Ay Lie,P Thayaalan

doi:10.1051/matecconf/201713801022

Abstract

This paper presents the change of material properties, such as decreasing of the compressive strength, splitting tensile strength, and porosity. The main objective of this paper is to analyze the mechanical properties of fly ash-based geopolymer concrete after being exposed to high temperature. The 28 th -day test specimens were burned for one hour at specified temperature variation of 200°C, 400°C, 600°C, and 800°C. Ordinary Portland Cement (OPC) concrete was used as a comparison. After burning at 400°C, the compressive strength of geopolymer concrete was surprisingly increased up to 27% of its normal strength. On the other hand, the compressive strength of OPC concrete decreased 67% from its normal strength. The splitting tensile strength of geopolymer concrete also decreased at the range of 50-70%. The porosity of concrete has a sufficient effect to compressive strength and splitting strength. X-Ray Diffraction (XRD) test of geopolymer concrete at temperature 400°C until 600°C showed some minerals change. Geopolymer concrete is proved to have better fire resistance compares to Portland Cement Concrete.

Highlights

Fires that lead to the increasing of significant temperature have an impact to the changes of properties of concrete such as mechanical, physical and chemical properties [1]
The high temperature affects the characteristics of concrete such as the decreased at strength, peeling surface on concrete, and the occurrence of cracks
At the temperature of 400°C, compressive strength of geopolymer concrete was 14.67% higher compared to the compressive strength of geopolymer at the normal temperature

Summary

Introduction

Fires that lead to the increasing of significant temperature have an impact to the changes of properties of concrete such as mechanical, physical and chemical properties [1]. The high temperature affects the characteristics of concrete such as the decreased at strength, peeling surface on concrete, and the occurrence of cracks. Geopolymer concrete is known as concrete that uses non-Portland binder in the mixture. As a substitute for cement, Material that has high silica and alumina content such as fly ash is chosen. Fly ash needs alkali activator to create a binder. Used alkali activator is the mixture of sodium hydroxide 8 M to 14 M and sodium silicate with the ratio of 0.4 to 2.5 [2]

Objectives

Findings

Discussion

Conclusion