地下构筑物混凝土裂缝控制

城市土地资源紧缺．楼字间间距小，当支护挡土桩作为地下室外侧壁单面模板时，如何进行侧壁混凝土裂缝控制以确保地下室使用功能成为关键。混凝土结构自防水是根本．裂和渗紧密相关，裂是渗的主要原因，抗裂比抗渗更重要，不解决裂，渗是难以从根本上解决的。要抗裂就要补偿混凝土的收缩，把裂和渗问题同时解决的有效途径．从材料角度说，是用补偿收缩混凝土替代普通混凝土．同时采用弹性模量较小的混凝土。另外，还需改善混凝土的边界条件，设计上需适当提高水平构造(温度)钢筋。

Control for concrete crevice of underground structures

Because it is lack of resources for soil in city,and there are small spaces between buildings,how to control the crevice in the side of concrete for insuring the application functions of basement becomes linchpin,when the timbering block is as the single template in the outer side of basement.The self-waterproof function is the basis, crevice and seepage have close relevant relationship.Crevice is the main reason for seepage,resisting the crevice is more important than resisting seepage.Without settling the problems of crevice,it is very difficult to settle the problems of seep fundamentally.The shrinkage of concrete must be repaired for resisting the crevice.The efficient aproach from the aspect of material is to settle the problems of crevice and seepage in the same time for using the compensating shrinking concrete to substitute the general concrete,and adopt the smaller elastic modulus cncrete.In addition,the conditions of boundary for concrete must be improved also,and the horizontal structure(temperature) of reinforcing steel bar must be improved from the design..