混凝土施工期表面保护仿真研究

低龄期混凝土表面开裂问题已成为工程界普遍关注的问题。这个问题反映到施工中,需要研究混凝土早期强度成长规律,以及不同龄期拆模时,混凝土表面应力发展规律。课题组通过研制的仿真分析软件FZFX3D,考虑混凝土浇筑过程,以离开基础约束区一定距离的某个浇筑块为研究对象,系统研究寒潮、气温日变幅和气温年变幅等三种温度荷载对向家坝碾压混凝土纵向围堰表面应力的影响。比较了不同龄期拆模的混凝土,其特征点的温度与应力变化过程,为施工期混凝土拆模后的表面保温材料选择,提供了参考依据。

Study 0n C0ncrete Surface Protection during Construction Period

The cracking problem of early age concrete surface has aroused general concern in engineering circles.It is necessary to study the laws of growing in strength of concrete at early stage and the laws of surface stress development of concrete with different ages when formwork is removed in terms of dam construction.This paper has systematically studied the influence of three temperature loads,namely,cold wave,air temperature daily variation amplitude and air temperature yearly variation amplitude,on surface stress of the Xiangjiaba longitudinal RCC cofferdam by developing the simulation analysis software FZFX3D,taking into consideration the concrete placement process and taking a certain concreting block that is at some distance from the restraint zone of its foundation as an object of study.The paper has also compared temperature and stress variation processes of concrete with different ages at the characteristic points.The paper gives reference basis for selection of heat insulating material for protection of concrete surface after removal of formwork.