Drying Shrinkage of Heat-Cured Fly Ash-Based Geopolymer Concrete

Steenie Edward Wallah

doi:10.5539/mas.v3n12p14

Abstract

Fly ash-based geopolymer concrete is manufactured without using portland cement at all. This type of concrete has environmental benefit as it has very low of greenhouse gas emission compared to that resulted from the production of portland cement. In addition, it also utilizes waste or by-product material that makes it more environmentally friendly. This paper presents the study of drying shrinkage of heat-cured fly ash-based geopolymer concrete. Geopolymer concrete in this study used low-calcium fly ash as its source material, alkaline solution and aggregates normally used for ordinary portland cement concrete. Four series of test specimens with different compressive strength were prepared to study the drying shrinkage of this concrete. The test results were then compared with the calculated results of drying shrinkage as predicted by Gilbert Method which is normally used for ordinary portland cement concrete. Test results shows that the heat-cured fly ash-based geopolymer concrete undergoes very low drying shrinkage. The drying shrinkage strain at one year as calculated using Gilbert Method is much higher, about five to seven times, compared to the measured drying shrinkage strain from the tests.

Highlights

Environmental issue has become a crucial issue in concrete industry
This paper reports the study of drying shrinkage of fly ash-based geopolymer concrete by conducting relevant testing of drying shrinkage and comparing the test results with the developed formula or equation normally used for predicting drying shrinkage of ordinary portland cement (OPC) concrete
This study focused on the drying shrinkage of fly ash-based geopolymer concrete, where the procedure as in Australian standard, AS 1012.13 (1992) was used as the basis to determine the drying shrinkage through an experimental or laboratory testing

Summary

Introduction

Environmental issue has become a crucial issue in concrete industry. This is mostly because of the emission of greenhouse gasses from the production of portland cement as the primary binder in making concrete in the meantime. Many efforts have been trying in order to reduce the use of portland cement in concrete that in turn will reduce the greenhouse gas emission. Those efforts include the use of supplementary cementing materials and finding alternatives for portland cement. In this regard, fly ash-based geopolymer concrete is a good alternative since it does not use portland cement at all. Fly ash-based geopolymer concrete is a good alternative since it does not use portland cement at all This type of concrete becomes more environmentally friendly because it uses waste or by-product material which is fly ash. This paper reports the study of drying shrinkage of fly ash-based geopolymer concrete by conducting relevant testing of drying shrinkage and comparing the test results with the developed formula or equation normally used for predicting drying shrinkage of ordinary portland cement (OPC) concrete

Shrinkage of Concrete

Fly Ash-Based Geopolymer Concrete

Experimental Work

Shrinkage Test Results

Comparison of Test Results and Prediction

Conclusion