石灰岩高石粉含量机制砂混凝土配合比设计及性能研究

Study on Mixture Ratio Design and Performance of Manufactured Sand Concrete with High Content of Limestones

针对云南高速公路建设工程优质河砂紧缺,而石灰岩等矿石资源丰富,石灰岩机制砂的石粉含量又过高的问题。对石灰岩高石粉含量机制砂混凝土进行配合比设计研究,并对比研究了河砂和石灰岩高石粉含量机制砂C30、C50强度等级混凝土的拌合物性能、力学性能和耐久性能。结果表明:石灰石粉MB值为0. 2,石灰岩机制砂石粉含量高达15%的情况下,按照特定的配合比设计方法,可以配制出和河砂混凝土工作性、力学性能、耐久性能相当或者超过河砂混凝土的机制砂混凝土,同时单方混凝土节约水泥近40 kg。

In view of the shortage of high-quality river sand for the construction of expressway in Yunnan Province and the abundance of limestone ore resources,and the excessively high content of limestone powder in manufactured sand,the mixture ratio design of concrete with high-content limestone manufactured sand was studied.And the performance of mixture,mechanical properties and durability of C30 and C50 strength grade concrete with river sand and manufactured sand with high content of limestone were studied experimentally.The results show that with the manufactured sand,which have the 0.2 MB value of limestone powder and the as high as 15%content of limestone powder,the concrete mixture properties,mechanical properties and durability can be comparable to or better than the concrete with river sand by the specific mixture ratio design method.Meanwhile,nearly 40 kg of cement can be savedin unilateral concrete.