Influence of bacteria on the compressive strength, water absorption and rapid chloride permeability of concrete incorporating silica fume
Influence of bacteria on the compressive strength, water absorption and rapid chloride permeability of concrete incorporating silica fume
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DOI：
10.1016/j.conbuildmat.2012.07.029
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发表时间：
2012-12-01
影响因子：
7.4
通讯作者：
Rajor, Anita
中科院分区：
文献类型：
--
作者：
Chahal, Navneet;Siddique, Rafat;Rajor, Anita
本文研究了溶尿素细菌(Sporosarcina Pasteurii)对硅灰混凝土抗压强度、吸水率和快速氯离子渗透性的影响。优化了3种细菌浓度(10(3)、10(5)、10(7)个/ml)，并进行了进一步的混凝土配合比设计。在制作混凝土时，分别用5%和10%的硅灰取代水泥。分别在28d和91日龄进行抗压强度、吸水率和快速氯离子渗透性试验。试验结果表明，在混凝土中掺入巴氏杆菌提高了混凝土的抗压强度，降低了混凝土的孔隙率和渗透率。28d和91d的抗压强度分别提高了38.2 Mpa和44 Mpa。此外，105个细胞/毫升细菌的吸水率也有所下降。这种抗压强度的提高可能是由于沉积在毛孔内的细菌细胞表面。扫描电子显微镜显示，巴氏杆菌直接参与了碳酸钙的沉淀，这一点得到了X射线衍射的进一步证实。由于方解石在混凝土中的沉积，观察到混凝土的氯离子渗透性降低。(C)2012爱思唯尔有限公司。保留所有权利。
This paper presents the effect of the ureolytic bacteria (Sporosarcina pasteurii) on the compressive strength, water absorption and rapid chloride permeability of concrete made with silica fume. Three bacterial concentrations were optimized (10(3), 10(5), 10(7) cells/ml) and further designing of concrete mixes was done. In making concrete, cement was replaced with 5% and 10% of silica fume by weight. Tests were performed for compressive strength, water absorption and rapid chloride permeability at the age of 28 and 91 days. Test results indicated that inclusion of S. pasteurii in concrete enhanced the compressive strength, reduced the porosity and permeability of the concrete. Maximum increase of 38.2 MPa and 44 MPa in compressive strength at 28 and 91 days was observed. Moreover, reduction in water absorption was observed with 105 cells/ml of bacteria. This improvement in compressive strength was possibly due to deposition on the bacteria cell surfaces within the pores. Scanning electron microscopy revealed the direct involvement of S. pasteurii in calcium carbonate precipitation which was further confirmed by XRD. Due to calcite deposition in concrete it was observed that reduction in chloride permeability of concrete occurred. (C) 2012 Elsevier Ltd. All rights reserved.