We often say that the stone powder content in the finished products of machine-made sand refers to the content of particles with particle size less than 0.075mm in machine-made sand. Unlike natural sand, the stone powder content of these machine-made sands can be controlled. For soft materials such as limestone, the stone powder content is generally 15%-20%, and for hard materials such as granite, it is 10%-15%. However, it is not that the stone powder in the finished aggregate is not good. An appropriate amount of stone powder can optimize the gradation of concrete particles, improve the compactness of concrete, and then improve the comprehensive performance of concrete.
Particles smaller than 0.08mm in machine-made sand stone powder can be regarded as an inert admixture, which is relatively good for improving the performance of concrete. The machine-made sand in concrete contains a certain amount of stone powder, which can improve the overall performance of concrete, but the proportion of stone powder content should be well controlled. According to the strength of different concrete, the content of stone powder can be set as 3%, 5% and 7% respectively. If you want to control the content of stone powder in machine-made sand, In addition to selecting sand making equipment with superior performance and reliable quality, corresponding sand washing equipment should be configured in the sand and stone production line. At present, the technical parameters of sand for concrete of most hydropower stations require the content of stone powder to be 6%-18%, and the content of stone powder of sand for RCC is required to be 12%-22%.
The control of stone powder content in machine-made sand can be analyzed by field. The manual recycling method is mainly applicable to some small-scale machine-made sand production scale, or the manual recycling method can also be used for projects with spacious site, that is, the overflow water discharged by the sand washer during the production process can be naturally stored and dehydrated, and then these fine sands can be added with loaders and transportation equipment. In the wet sand making process, the content of stone powder in machine-made sand is generally low, and most projects require the recovery of some stone powder to meet the needs of the project. There are two main ways of stone powder recovery in machine-made sand of hydropower projects: mechanical recovery and manual recovery.
At present, natural sand resources are limited, and the application of sand production line has become more and more common. Machine made sand is made by mechanical crushing and screening. In the production process, it is inevitable to produce a certain amount of stone powder with particle size less than 0.075mm. Different from natural sand, the content of stone powder in concrete should be accurately controlled to make the application of concrete more regular and extensive.
