Compressive Strength Improvement and Water Permeability of Self-Healing Concrete Using Bacillus Subtilis Natto

Abstract

In recent years, many projects have been carried out to enhance the durability of concrete structure from the influence of cracks. Generally, managing cracks should be a rather preventative method for sustainable development. Based on that, Bacillus subtilis natto-a local bacterium in Japan was found to have the ability to form CaCO 3 , which can be used as healing materials for cracks in the concrete structure. The bacterial biomineralization immobilized in lightweight aggregate was studied to improve the compressive strength by healing the cracks and densifying the structure. Moreover, as an essential parameter for durability enhancement, the water permeability of self-healing concrete through a water-flow system was carried out. Experimental results on the behavior of the materials indicate that Bacillus subtilis natto could lead the compressive strength to 40 % higher than the controls. Promising result in preventing the water through the cracks confirmed the self-healing effect with more potential in larger-scale.

Advancements in Exploiting Sporosarcina pasteurii as Sustainable Construction Material: A Review

“…A wide range of bacteria [38], including Sporosarcina pasteurii [2,[46][47][48][49][50][51][52][53][54][55], Bacillus Subtilis [14,[16][17][18]40,[56][57][58][59], Bacillus Cereus [20,60,61], and Bacillus Megaterium [23,24,62,63], as well as enzymes isolated from plants, such as Jack bean [42,45,64] and soybean [36,41,44], have been investigated in the literature. Navigating through the literature, however, it can be observed that Sporosarcina pasteurii (S. pasteurii) is the most widely employed bacteria, as it demonstrates a higher rate and quality of calcium carbonate precipitation due to its species characteristics [65,66].…”

“…Calcium carbonate (CaCO 3 ) precipitation is a naturally occurring phenomenon in different environments, including marine water, freshwater, and soils. Microbially induced calcium carbonate precipitation Induced Calcium Carbonate Precipitation (MICP), which exploits the microbial metabolic processes for bio-cementation to enhance the durability of construction materials, has drawn attention not only in soil stabilization [1][2][3][4][5][6][7][8][9][10][11] and building construction [12][13][14][15][16][17][18][19][20][21][22] but also in wind-induced desertification [23][24][25][26], stone artwork conservation [27], and even subsurface-related applications [28,29]. Microorganisms engaged in the nitrogen cycle, sulphate-reducing bacteria, and photosynthetic microorganisms have all been reported to induce calcium carbonate [30,31].…”