Research On Resources Status And Application Of Manufactured Sand In Guangxi

With the guidance of ASEAN economy in these years, the urban construction of Guangxi is speeding up as well, so the demand for the construction sand is growing remarkably. But the supply of natural sand can hardly meet the needs of market for natural sand dwindles. Therefore, the development of manufactured sand and spreading in using is badly needed. In this paper, the situation of manufactured sand and its application research in Guangxi, especially in Nanning was introduced, conclusions were as follows:As to present situation of resources, manufactured sand has been promoted and used to some extent in main cities of Guangxi Autonomous Region, such as Nanning, Guilin and Liuzhou. While currently, exceeding national standard of fine content in manufactured sand and big fine modulus are the most popular problems, because of the difference of process route for preparing sand and the lack of power removing apparatus.Raw materials for manufactured sand are high quality in Nanning and surrounding areas, and the dry process is the mainly production-technology. The pass rate for the finished product of extracted 12 groups of manufactured sand is 36.4%, and fine content exceeding limitation is the primary problem of unqualified manufactured sand. Therefore, many commercial concrete companies use it by mixing two different kinds of manufactured sand or a sort of manufactured sand and natural sand with a certain mass ratio.In applied research, qualified manufactured sand (QMS) and unqualified manufactured sand (UQMS) applied in mortar and concrete was studied through orthogonal experiment and uniform experiment, and part of their performance was compared too.The results showed that:the using of QMS in mortar was more economic, while in concrete the workability and compressive strength of 66.7% dosage of QMS were much better.In addition, the concrete prepared by QMS had a steady strength development. Test intensity of the concrete prepared by UQMS had a large discreteness and was not suitable for application in engineering. Reducing water-cement ratio and increasing slag dosage could help to improve the resistance to chloride ion permeability, however, improving the content of mineral admixtures could reduce carbonation resistance of concrete.