城市轨道交通地下车站主体结构混凝土裂缝控制试验研究

Study on Concrete Crack Control of Underground Engineering Structure in Urban Rail Transit Project

抑制快速温升、温降条件下的收缩开裂是控制城市轨道交通地下车站主体结构混凝土渗漏的关键。依托在建的常州市城市轨道交通1号线工程,通过抗裂功能材料的应用及系列配合比的设计,对混凝土强度、绝热温升、早龄期变形性能、耐久性能进行了系统测试,在此基础上,调整优化配合比,并进行工程应用。结果表明,采用具有温度与膨胀历程双重调控功能的HME-V(温控、防渗)高效抗裂剂,实现了混凝土温升和收缩性能的双重调控,制备出的混凝土满足力学、抗裂及耐久性的要求,通过对实体结构混凝土制备、浇筑、监测的各个环节的控制,实现了地下车站主体结构无贯穿性收缩裂缝的出现。

The inhibition of shrinkage cracking under the condition of rapid temperature rise and temperature drop is the key to control the leakage of concrete in the main structure of underground station in urban rail transit project. Relying on the construction of Changzhou urban rail transit line 1 project, through the application of anti-cracking functional material and the design of series concrete mix proportions, the thermal,mechanical, deformation properties and durability were tested, on this basis, the mix proportions were optimized and used in the engineering application. The results indicated that the use of dual-regulation technology of temperature field and expansion history reduced concrete temperature rise and temperature drop shrinkage at the same time; the mechanics, crack resistance and durability of the prepared concrete meet the requirements; no penetrating cracks were observed in the main structure of the underground station.