Title |
The Effect of Microorganisms on Compressive Strength of Cement Paste |
Authors |
Lee, Jun-Cheol ; Kim, Wha-Jung ; Chun, Woo-Yong ; Lee, Chang-Joon |
Keywords |
Microorganism ; Cement Paste ; Compressive Strength ; Hydration |
Abstract |
This study investigated the effect of microorganisms on compressive strength development of cement paste. The Sporosarcina pasteurii used in this study was capable of microbial induced calcite precipitation(MICP). Four different cell concentrations were selected ranging from 10 to 107 per ml. distilled water as mixing water. From experimental results, cement paste with microorganisms showed higher strength gain compared with reference cement paste at earlier ages. From TG/DSC analysis, more calcium hydroxide was observed in the cement paste with microorganisms. The degree of hydration of the cement paste with microorganisms, evaluated by measuring non-evaporable water contents in cement paste, was also higher than that of reference cement paste. It is very likely that the strength improvement of cement paste is due to acceleration of hydration process caused by the metabolism of microorganisms. Further investigation is in progress to identify the specific mechanisms which is responsible for the improvement of compressive strength in early ages. |