跳仓法与补偿收缩混凝土组合技术在地下室工程中的应用研究

Application of combination technology of alternative bay method and shrinkage compensation concrete in basement engineering

采用钙镁复合膨胀剂配制补偿收缩混凝土能够弥补跳仓法施工的混凝土存在收缩变形过大的缺陷,跳仓法与补偿收缩混凝土组合技术在工程实体结构应用中具有较好的裂缝控制效果。实体结构监测数据表明,混凝土内部早期温度修正后微应变为31με~104με,60 d龄期内缓慢降低至-153με~-48με,采用钙镁复合膨胀剂配制的补偿收缩混凝土在较长龄期内收缩量较小,开裂风险较低;不同板块收缩变形量与跳仓接壤板块数量和分块结构尺寸2个因素有关;可通过增加保温材料层数或厚度以控制早期降温速率和温降收缩量。

The shrinkage-compensating concrete prepared by calcium and magnesium oxides based expansive agent can make up for the defects of excessive shrinkage deformation of concrete in the alternative bay constructon method.The combination technology of alternative bay method and shrinkage-compensating concrete has a good crack control effect in the application of engineering solid structure.The monitoring data of the solid structure show that the early maximum micro-strain with temperature correction of the concrete was about 31 με~104 με,and the micro-strain value was slowly reduced to about-153 με~-48 με in the 60 d age.The shrinkage-compensating concrete prepared with calcium and magnesium oxides based expansive agent had smaller shrinkage and lower cracking risk in a longer age.The amount of shrinkage deformation of different plates was related to the number of adjacent plates and the size of block structure.The early cooling rate and temperature drop shrinkage could be controlled by increasing the number or thickness of insulation materials.