Most mechanical sand is produced by sand making machine, and the sand is with angular particle and rough surface, as well as sociable to be bonded with cement and other cement materials, so it’s good to increase concrete strength. Superficially, mechanical sand has disadvantages of poor transformation, but the stone powder in it can make up for this deficiency. The stone powder is a kind of inert additives, with small fineness, so it can replenish fine grain for concrete, increasing the ratio of solid surface area to water volume, thereby reducing bleeding and segregation.
With rapid development of China economy, resources of natural sand are depleted. Therefore, the increasing infrastructure projects in China sand making machine sand came into being, and using and production mechanical sand has become a trend. This document explains the performance characteristics, present situation and application of mechanical sand.Stone powder can bond cement and water to form soft slurry, which increases the amount of concrete slurry, reduces friction between sand, thereby improving the work ability of concrete. However, stone powder content in mechanical sand is limit, if exceeds this limit, with the increasing of stone powder content water consumption of mixed concrete, mixed concrete will be dry and thicken, which will lead to concrete cracks and decreasing in intensity.
Mechanical sand is mainly used for civil construction industry, and they are divided into three levels according to their technical requirements. The first level is for concrete with strength greater than C60; Class two is for concrete with grade C30-C60, strength and frost resistance, impermeability and other requirement; Class three is advised for concrete and building mortar with strength level less than C30. Mechanical sand has many advantages, and also has been applied in some of the largest civil engineering construction projects.