现代混凝土早期收缩裂缝及控制技术

Early Shrinkage Cracking of Modern Concrete and Its Inhibiting Technology

现代混凝土复杂的组分、较高的早期强度,高温、干燥等严酷服役环境,以及超长、大体积、强约束等结构特征,导致收缩开裂问题突出,影响结构服役功能及寿命.围绕上述技术难题,对现代混凝土收缩开裂的主要原因进行分析;就多因素耦合作用的抗裂性评估研究进展进行介绍;针对凝结前的塑性裂缝、硬化阶段温湿度耦合变形开裂及长期干燥收缩开裂问题,提出了相应的调控措施.

Cracking tendency of modern concrete are exacerbated by its complex composition, high early-phase strength and temperature, drying and other severe environment, as well as its overlength, massive and strong restraint structural features which affecting structural service function and lifespan. Focusing on the above technical problems, the main reasons of shrinkage cracking of modern concrete are analyzed, and the research progress of cracking resistance evaluation of multi-factor coupling is introduced. Finally, the corresponding inhibiting measures are proposed to deal with the plastic cracking before coagulation, the hardening cracking of hygro-thermal deformation and the long-term dry shrinkage cracking.