Abstract:
Gansu Province is located in the northwest arid area. There are few rivers in Gansu Province. There are only a few rivers such as Jinghe River and Weihe River. With the decrease of river sand mining quantity, the price of river sand is rising while the quality of river sand is declining seriously, which is manifested in the excessive mud content and unqualified gradation. Driven by the economic interests, many places have used mountain sand and weathered sand as river sand. The concrete mixed with unqualified sand needs a lot of water, the slump loss is serious, the mix proportion of construction can not be controlled, and the concrete body is prone to crack, color difference and other diseases, even the strength can not meet the design requirements The project quality is affected.