| With the development of infrastructure construction and recognition of environment protection, existing natural sand can not meet the demand in engineering, so manufactured sand will the trend of development in future. During the process of manufactured sand, it's inevitable to produce some stone powder in size less than 75 um,which is one of the most apparent differences. Compared with natural one, manufactured sand has the characteristics of worst graduation, big fine modulus, rugged surface and sharp particle. Therefore, most engineers don't know whether Manufactured Sand (MS) can be used to prepare concrete with high performance and high strength, even know little about its performance, so that high strength Manufactured Sand Concrete (MSC) is very difficult to be used in some important construction.Based on the preparation and performance test of C60 MSC, how the content of stone powder and clay powder effect the workability, strength, elastic ratio, dry shrinkage, diffusion coefficient of Cl" and freeze-thaw resistance are studied in this paper. Also, the using and effect of FA and GBFS in MSC with high stone powder content and the influence of stone powder instead of admixture on workability and strength are further studied and evaluated.It's proved that: (1) The MSC prepared properly has the same excellent performance as the crude sand concrete. (2) When preparing C60 MSC, the GB limit content of stone powder can be widened from 5% to 10.5%, besides, part of the powder can be used as admixture and it can replace about 10% amount of cement. (3) The content of stone powder affect slightly the effect of FA on workability and strength of concrete. (4) High amount of clay powder has bad effects on the workability, shrinkage and freeze-thaw resistance of C60 MSC. Additionally, according to the characteristics of MS and MSC, the selection of sand ratio, the content of admixture, the supposed bulk, the limit content of stone powder are concluded to design the mix-proportion of MS-HPC. |
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