掺复合抗裂剂的地下车站混凝土抗裂性能试验研究与工程应用

Experimental study and engineering application of anti crack performance of underground station concrete mixed with composite anti crack agent

为提升轨道交通地下车站混凝土的抗裂性能,采用具有微膨胀、缓凝效果的复合抗裂剂,研究其掺量、养护温度对C35、C50混凝土强度及膨胀性能的影响。结果表明:随抗裂剂掺量增加,混凝土强度先增加后减小,且8%掺量时力学性能、限制膨胀率及收缩性能最佳;随养护温度升高,极大促进了C35混凝土强度及膨胀性能的发挥,且C50混凝土的膨胀性能也得到发展;试验段的成功应用表明,具有补偿收缩、预防早期裂缝的效果,有效减少了混凝土的开裂。

In order to improve the crack resistance of concrete in rail transit underground station,a composite crack inhibitor with micro expansion and retarding effect was used to study the effects of its content and curing temperature on the strength and expansion of C35 and C50 concrete.The results show that the strength of concrete increases first and then decreases with the increase of the content of anti crack agent,and the mechanical properties,limited expansion rate and shrinkage properties are the best when the content of 8%;with the increase of curing temperature,the strength and expansion performance of C35 concrete are greatly promoted,and the expansion performance of C50 concrete is also developed;through the successful application of the test section,it has the effect of compensating shrinkage and preventing early cracks,and effectively reduces the cracking of concrete.