Quality assessment standards and production technology of artificial sand based on hydraulic concrete construction specifications

Abstract

Natural sand and gravel resources are a local resource. Natural sand and gravel are non-renewable in a short time and are not suitable for long-distance transportation. After decades of mining, sand and gravel resources in some areas have been exhausted. The transportation distance of natural sand and gravel is getting farther and farther, and accordingly, the price of natural sand and gravel continues to rise. At the same time, continuous and disorderly mining has caused serious damage to the environment and resources. During the construction of large and medium-sized water conservancy and hydropower projects in China, due to the lack of surrounding natural aggregates, most projects use artificial aggregates. In the current national standards for water conservancy projects, the content of artificial sand and gravel powder is clearly defined. Based on the “Hydraulic Concrete Construction Specifications” (SL677-2014), this article summarizes the particle shape, gradation and surface structure of artificial sand, and also calculates the theoretical gradation of artificial sand. To find out the impact of stone powder content on the performance of artificial sand, different levels of stone powder content need to be selected for research and analysis to clarify the impact of artificial sand powder content on concrete properties. Research shows that for concrete made from artificial sand, increasing the aggregate content with a particle size less than 0.075 mm can significantly increase the compressive strength of the concrete. In artificial sand, the content of stone powder will affect the workability, polishability, durability, permeability and water release of concrete. In the artificial sand and gravel production process system, crushing and sand making equipment are the most important sand and gravel production equipment. The research results provide theoretical reference for the application of artificial sand in concrete and the update of artificial sand production technology and equipment.