贵州部分地区C30机制砂混凝土配合比优化研究

Study on Mixing Proportion Optimization of C30 Manufactured Sand Concrete in Some Areas in Guizhou

针对贵州部分地区机制砂混凝土在实际工程中存在的问题,在C30机制砂混凝土配合比的基础上,改变水泥用量、粉煤灰掺量、减水剂掺量及砂率,研究坍落度及抗压强度的影响,并对C30机制砂混凝土的配合比进行优化。研究结果表明:提高水泥用量可改善机制砂混凝土的抗压强度;粉煤灰可改善其坍落度,但会降低抗压强度;减水剂在机制砂混凝土中存在饱和点。此外,合适的砂率可改善混凝土密实度,进而提高混凝土抗压强度,当砂率为44%时,机制砂混凝土抗压强度最高。

Aim at this actual engineering problem about cement concrete with the manufactured sand as the fine aggregate,the mixing proportion of concrete was investigated.The effect of superplasticizer,cementitious and manufactured sand ratio on the compressive strength and fluidity were studied.Results showed that superplasticizer can improve the fluidity of concrete,but a saturation point was found for mortar and concrete with the manufactured sand as fine aggregate.The cementitious content can affect the fluidity and compressive strength of concrete.In addition,the manufactured sand ratio affect and compressive strength of concrete due to the compactness of aggregate.The optimal aggregate grading was achieved when the manufactured sand ratio of 44%was used.