DIYALA JOURNAL OF ENGINEERING SCIENCES

Abstract

The aim of the study was to using of bacteria to self-healing of cracks in concrete, and this study was the first of its kind in Iraq. This study used bacteria Bacillus Subtilis isolated from agricultural soils and dry soil, and has the cultivation and development in the selective medium SR-20, underwent tests, biochemical and diagnose bacteria and according to the (Bergys Manual & Medical Bacteria), where conducted laboratory tests preliminary to know the ability of these bacteria to address cracks concrete in terms of their ability to withstand factors existing in the form of concrete, including the pH baseband through development in the selective medium SR-20 with a pH baseband (PH=10), and tolerance of salinity when planted in the precipitation medium SM-7 containing chloride Calcium, also was testing Preparation Material treat cracks for the deposition of calcium carbonate crystals.
The results also showed that the best way to prepare material treat cracks concrete to precipitate calcium carbonate are using the method consisting of silica + bacteria concentration (15×10), where results showed test ultrasound acoustic difference in the time it takes the wave to pass through cracks treatment in the experience of substance treatment consisting of silica + HCl + bacteria concentration (15 × 10), and the time it takes the wave to pass through the cracks of treatment in the experience of substance treatment consisting of silica + bacteria concentration (15 × 10), where results showed that Article therapy were completely rigid in the last test. The test results also showed scanning electron microscopic examination (SEM) create calcium carbonate to treat cracks material consisting of silica + bacteria.