广州地铁C50混凝土管片外观气泡及麻面控制技术

Control Technology for Appearance Bubbles and Pitting Surface of C50 Concrete Segments in Guangzhou Metro

该文研究了混凝土原材料及配合比对混凝土拌合物性能、力学性能、表面气泡分布及麻面比例的影响规律。结果表明:与水泥品种相比,混凝土外加剂复配措施对混凝土拌合物性能、力学性能和气泡分布与麻面比例的影响更明显,相对而言,在基准外加剂的基础上进一步增加0.1 g引气剂及0.1 g消泡剂时混凝土表面气泡最少,麻面比例更低。胶凝材料用量、砂率、碎石比例对混凝土表面气泡分布与麻面比例也有不同程度的影响,总体而言,影响程度由大到小为胶凝材料用量>碎石比例>砂率。相对而言,C50混凝土的胶凝材料用量为470 kg/m^(3),砂率为34%,10~25 mm与5~10 mm碎石搭配比例为8/2时,混凝土表面1 cm以上气泡最少,麻面比例最低。

This article investigates the influence of concrete raw materials and proportion on the performance,mechanical properties,surface bubble distribution,and pitting surface ratio of concrete mixture.The results show that compared to cement varieties,the effect of concrete admixture compounding measures on the performance,mechanical properties,bubble distribution,and ratio of pitting surface on the concrete mixture is more significant.Relatively speaking,when adding 0.1g of air entraining agent and 0.1g of defoamer on the basis of the reference admixture,the air bubbles on the surface of concrete are the least,and the proportion of fitting surface is lower.The dosage of cementitious materials,sand ratio,and gravel ratio also have varying degrees of influence on the distribution of bubbles and the proportion of pitting surface on the concrete surface.Overall,the degree of influence ranges from large to small as follows:cementitious material dosage>gravel ratio>sand ratio.Relatively speaking,when the amount of cementitious material used in C50 concrete is 470 kg/m 3,the sand content is 34%,and the ratio of 10~25 mm to 5~10 mm gravels is 8/2,the air bubbles above 1 cm on the surface of concrete are the least,and the proportion of fitting surface is the lowest.