微生物灌浆碳酸钙沉积规律

Deposition Regularities of Calcium Carbonate on Microbial Grouting

为揭示碳酸钙在混凝土裂缝内部的沉积规律,提高封堵效率,针对混凝土劈裂裂缝,设计了10组自重作用下的灌浆试验.试验参数包括灌菌量、裂缝底部有无菌液过滤层(医用棉团)、是否提前在裂缝内灌注菌液固定液等.结果表明:灌入菌液越多,修复裂缝效率越高.对于裂缝底部有菌液过滤层的试件,碳酸钙易在裂缝底部生成;对于裂缝底部没有菌液过滤层的试件,碳酸钙易在裂缝中下部生成.提前灌注菌液固定液的试件比未提前灌注试件的修复效果更佳.随着灌浆循环次数和裂缝竖向深度的增加,裂缝内壁碳酸钙层厚度不断增大.裂缝内壁越粗糙、竖向倾角越大,以及裂缝迂回处碳酸钙越容易沉积.

In order to reveal the deposition regularities of calcium carbonate in the crack and improve the sealing efficiency,ten groups of grouting tests under gravity in concrete split cracks were conducted.The test parameters included different volumes of bacterial liquid,whether the bottom pasted bacteria liquid filtered layer(medical cotton)at the bottom of the crack,or the bacterial fixation liquid is poured into the crack before grouting.The results show that the more bacterial liquid poured into the crack,the more efficient it is for repairing cracks.The calcium carbonate is firstly formed at the bottom of the crack in the specimen which has the bacterial liquid filter layer at the bottom of the crack and calcium carbonate is firstly formed in the middle and lower part of the crack in the specimen which has no bacterial liquid filter layer.The specimen filled with the bacterial fixation liquid before grouting has more repairing efficiency than the specimen that is not filled.With the increase of grouting cycles and depths of crack,the thickness of calcium carbonate in crack inner wall is increased.Calcium carbonate is more likely deposited in the rough,high vertical inclination and roundabout internal wall of the crack.