粗骨料宏观粒形特征对混凝土配合比及性能影响

Study on the influence of macro particle shape characteristics of coarse aggregate on concrete mix proportion and performance

以蒙城枢纽为例,为更好地解决大体积混凝土施工带来的温度及裂缝控制问题,使用两批不同宏观粒形特征的骨料开展混凝土配合比验证及优化工作,性能试验的结果表明,两批粗骨料均能配制出满足设计要求的混凝土,耐久性完全满足设计要求并且有较大富余。另外,采用第二批粗骨料拌制的混凝土,在保证拌合物工作性能、力学性能和热学性能的前提下,其水泥用量最多可降低29 kg/m^(3),28 d绝热温升值可最多降低4.3℃,对温控有利。

Taking Mengcheng junction as an example, in order to better solve the problems of temperature and crack control caused by mass concrete construction, two batches of aggregates with different macro grain shape characteristics are used to carry out the verification and optimization of concrete mix proportion. The results of performance test show that the two batches of coarse aggregate can be prepared to meet the design requirements of concrete, and the durability fully meets the design requirements, and there is a large surplus. In addition, under the premise of ensuring the working performance, mechanical properties and thermal properties of the mixture, the cement consumption of the concrete mixed with the second batch of coarse aggregate can be reduced by 29 kg/m^(3)at most, and the adiabatic temperature rise of 28 d can be reduced by 4.3 ℃ at most, which is favorable for temperature control.