Study of Volcanic-Ash-Impregnated-Bacteria Filler to the Compressive Strength of Concrete

^{1, 3} Department of Civil Engineering, State University of Jakarta, 13220 Rawamangun, Indonesia
² Biomaterial Research and Development Center, Indonesian Institute of Sciences (LIPI), 16911 Cibinong, Indonesia

^* Corresponding author: hendryanjar@gmail.com
^* Corresponding author: ananto@biomaterial.lipi.go.id
^* Corresponding author: ririt-aprilin@unj.ac.id

Abstract

Technology of concrete has been advanced recently to improve the properties of concrete. Utilization of ash as the substitute of cement or filler of concrete also indicates good result in compressive strength concrete in certain amount. Harnessing the bacteria for self-healing concrete has also been successfully performed in order to maintain the destruction of the concrete by itself. Past research indicated that bacteria can be beneficiary to improve the compressive strength, absorption, permeability, and so on. In this paper, Bacillus Altitudinis was extracted from the karst (source from the limestone mountain) and bred through liquid media to be impregnated inside the volcanic ash. The impregnated bacteria in volcanic ash were used as the filler to the concrete mixture with the proportion of filler varied from 1%, 1.5% and 2% to the weight of cement. Mechanical properties of the concrete specimen showed that the compressive strength reached its best when the filler proportion was 1.5%. The absorption referred analogously to the increment of compressive strength due to the success of filling the void inside the concrete. Based on compression test to all the concrete specimens, there was enhancement about 18% and the average absorption can be abated around 23%. Future research due to some drawbacks turning up is the need of developing another media for bacteria to live and making sure the exact amount of bacteria impregnated to the media so that the desired advance of concrete compressive strength can be acquired.