细菌诱导碳酸钙沉积修复混凝土裂缝  

Remediation of concrete cracks by bacterially-induced calcium carbonate deposition

作　　者：李沛豪[1] 屈文俊[2] 

机构地区：[1]浙江工业大学,浙江杭州310014 [2]同济大学,上海200092

出　　处：《土木工程学报》2010年第11期64-70,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50678127);国家科技支撑计划(2006BAJ03A07-04);国家重点基础研究发展计划(2009CB623200)

摘　　要：提出生物沉积修复混凝土裂缝的方法,通过XRD、SEM、混凝土抗压及抗弯试验,研究细菌诱导碳酸钙晶体在混凝土表层沉积的晶相、微观形貌及生物沉积对混凝土裂缝的修复效果。结果表明:沉积晶体的晶相为方解石和球文石;对于菌种Sporosarcina pasteurii,Ca2+源影响沉积晶体的晶相类型,Ca2+浓度影响沉积晶体的形貌和尺寸,沉积晶体在混凝土表层形成了有效的防护层;混凝土裂缝经生物沉积修复后,抗压强度随裂缝深度增加而增加,最大增加了15.3%;梁试件跨中极限荷载随裂缝深度增加而减小,极限荷载最大增加了8.5%,浅层裂缝恢复效果较深层裂缝明显。Biodeposition had been proposed as a novel technique to remedy concrete cracks. Laboratory experiments were conducted for bacterially induced carbonate deposition on the surface of concrete samples. The crystal phase and growth morphology of the deposited mineral layer were analyzed by using XRD and SEM, respectively. The efficacy of concrete cracks remediation was studied through compressive strength test and flexural failure test. Experimental results show that the mineral crystal phases are calcite and vaterite. For bacterium Sporosarcina pasteurii, calcium source has an effect on the phase of calcium carbonate mineralization, and the crystal shape and size of calcium carbonate is influenced by Ca2＋ concentration in culture medium. The crystal deposits uniformly on the surface and subsurface of the concrete samples, working as a surface treatment effectively protecting the concrete. The compressive strength enhancement of concrete samples with cracks increases with the increase of the crack depth, with the maximum increment being up to 15.3%. Ultimate concentrated load enhancement of concrete beams with cracks at mid-span decreases with the increase of the crack depth, and the maximum increment is up to 8.5%. Remediation of shallow cracks is more efficient than that of deeper ones. Evidences show that biodeposition has a great potential for remediation of concrete cracks.

关 键 词：细菌 生物沉积 生物修复 混凝土 裂缝 抗压强度 

分 类 号：TU528[建筑科学—建筑技术科学] TU375.02