Strength and durability performance of alkali-activated rice husk ash geopolymer mortar.

Byung-Jae Lee,Yun Yong Kim,Velu Saraswathy,Seung-Jun Kwon

doi:10.1155/2014/209584

Abstract

This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2 and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

Highlights

The production of one ton of cement emits approximately one ton of carbon dioxide to the atmosphere which leads to global warming conditions [1, 2]
It is a habitual practice to incorporate these materials to hydraulic binders as a solution to their final confinement; besides that, in many occasions, the incorporation results in improvements of the properties of the resulting material as much in mechanical properties and durability [8, 9] Among the supplementary cementitious materials fly ash (FA) and ground granulated blast furnace slag (GGBFS) are widely used for high volume replacement for their enhancement of engineering properties [10, 11]; the other materials can be considered for reuse or reutilization of resources
Kusbiantoro et al studied the effect of FA based geopolymer concrete and found that elevated temperature is suitable for rapid dissolution of silicate monomer and oligomer from microwave incinerated rice hush ask (RHA) surfaces, which supports

Summary

Introduction

The production of one ton of cement emits approximately one ton of carbon dioxide to the atmosphere which leads to global warming conditions [1, 2]. It is important to reduce the CO2 emission through usage of waste materials like fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBFS), and rice hush ask (RHA), which contributes to the improvement of the binder properties such as long-term strength, permeability, and durability [3,4,5]. The amorphous silica contained in RHA can react with cementitious binders to perform pozzolanic activity [12]. Geopolymer binders have been reported as being acidresistant [14], economical, environmentally-friendly, and more absorbent of liquids and produce a highly durable product [15]. Kusbiantoro et al studied the effect of FA based geopolymer concrete and found that elevated temperature is suitable for rapid dissolution of silicate monomer and oligomer from microwave incinerated RHA surfaces, which supports

Methods

Results

Conclusion