大体积现浇抗裂混凝土施工裂缝防治研究

Research on the Prevention and Control of Construction Cracks of Mass Cast-in-place Anti-cracking Agent Concrete

在大体积混凝土施工中由于大幅度温度升降引起的微应变,而导致微裂缝的产生与发展,为此,混凝土抗裂剂凭借出色的补偿收缩性能在大体积混凝土施工中得到了试验与运用。本文运用补偿收缩混凝土技术,研究添加不同浓度HME-V抗裂剂掺量(0%,4%,8%,12%,16%)的抗渗混凝土施工和易性、散热情况及力学性能,同时和掺入0.4%聚丙烯纤维的抗渗混凝土做对比研究,采用Abaqus有限元软件对隧道的顶板与侧墙施工过程中的温度场与塑性损伤进行数值模拟计算。试验结果表明,抗裂剂配制的抗渗混凝土和易性更佳,力学性能相较原始混凝土有良好的保证,并在塑性损伤及大体积散热方面有不错的表现。

In order to control the strain caused by large temperature drop in mass concrete construction,which leads to the generation and development of micro cracks,concrete anti-cracking agent has been tested and applied in mass concrete construction with its excellent performance of compensating shrinkage.In this paper,the construction workability,heat dissipation and mechanical properties of impermeable concrete with different concentrations of HME-V anti-cracking agent(0,4%,8%,12%,16%)are studied by using the shrinkage compensating concrete technology.Meanwhile,it is compared with the impermeable concrete with 0.4%polypropylene fiber.ABAQUS finite element software is used to numerically simulate the temperature field and plastic damage during the construction of the roof and side walls of the tunnel.The test results show that the impermeable concrete prepared with anti-cracking agent has better workability,better mechanical properties than the original concrete,and has good performance in plastic damage and mass heat dissipation.