Effects of microbial agents to the properties of fly ash-based paste

¹ Department of Civil Engineering, Institut Teknologi Sepuluh Nopember, 60111 Surabaya, Indonesia
² Indonesian Consortium for Geopolymer Research, Institut Teknologi Sepuluh Nopember, 60111 Surabaya, Indonesia
³ Department of Civil and Environmental Engineering, Hosei University, 102-8160 Tokyo, Japan
⁴ Department of Applied Chemistry and Biochemistry, National Institute of Technology, 644-0023 Wakayama, Japan

^* Corresponding author: januarti@ce.its.ac.id

Abstract

Specific microbial agents such as bacteria are often used in concrete to improve its performance. Some microbes act as self-healing agents to close cracks in concrete, and to increase concrete strength. This paper presents a study to observe the effects of microbe addition to two types of concrete mixtures the fly ash-based, as geopolymer paste, and portland cement paste containing fly ash. Furthermore, the investigation was conducted to compare the properties of each paste, such as its compressive strengths, specific gravities, porosity, microstructures, and XRay diffracting properties. The results indicate that microbial activities positively affected the properties of both, portland cement paste and geopolymer paste. The result reported here strongly suggests that fly ash can be used to produce a high quality, but environmental friendly construction material when it’s mixed together with useful microbes.