Sustainable utilization of ultrafine rice husk ash in alkali activated concrete: Characterization and performance evaluation

Abstract

This paper investigates the novel effect of ultrafine rice husk ash (URHA) on the properties of alkali-activated concrete. Rice husk ash was obtained as waste from biomass energy production and further processed to obtain URHA. The URHA was first characterized using various techniques to understand its morphology, structure and chemical composition. The URHA was then used to replace fly ash in alkali-activated fly ash/slag concrete up to 10%, and the effects on the performance were evaluated. The optimum dosage of URHA was assessed based on the compressive strength and the resistance to chemical attacks was carried out on the control mixture and that incorporating the optimum URHA. Microstructural properties of some of the control mixture and that incorporating the optimum URHA content was also investigated. Results from this study showed that the use of URHA as a 5% replacement of the FA is optimum that ensured high performance.

Keywords:

• Alkali-activated concrete
• geopolymer
• rice husk ash
• compressive strength
• workability
• chemical attacks

Acknowledgement

All the authors are thankful to Grøn Tek Concrete & Research, Bhubaneswar, India for the financial support provided to conduct this research. This research work was also partially funded by ASTM International (Das S.K. et al. ASTM International student project grant for the year 2018-19, hence the authors highly appreciate ASTM International for the support. The first author acknowledges the support of Mr. Saurabh Kumar Singh, Prof. Sitansu Kumar Das, and Prof. Trilochan Sahu of Government College of Engineering, Keonjhar, India for their continuous support during the funding acquisition and experimentations. The authors are thankful to CSIR-IMMT, Bhubaneswar, India for research facilities and Prof. Ajit Behera, NIT Rourkela, India regarding the XRD and SEM of the URHA during the study.

Disclosure statement

No potential conflict of interest was provided by the author(s).