稻壳灰不同掺量对混凝土性能影响测试与比较研究

Test and Comparative Study on the Effect of Different Content of Rice Husk Ash on the Concrete Performance

稻壳灰具有优良的微集料填充效应和火山灰活性,按一定比例掺量加入到混凝土中能够有效改善混凝土的多项性能。本文采用不同比例稻壳灰等量部分替代水泥制备稻壳灰混凝土,并对其耐久性(抗渗性能、耐磨性性能)和微观性能(扫描电镜(SEM)分析、EDS分析和纳米压痕)进行了细致的测试和研究。试验结果表明,稻壳灰的加入能够显著改善混凝土的耐久性和微观性能,随着稻壳灰掺量不断增加,稻壳灰混凝土的抗渗性能也不断增强,当稻壳灰掺量为20%时,其耐久性能达到最佳状态;SEM、EDS分析表明稻壳灰混凝土的微观结构中无明显孔隙存在,且有大量水化硅酸钙凝胶生成;纳米压痕结果表明稻壳灰加入有效提高了水泥的水化速率,增加了高密度水化硅酸钙凝胶的数量,增加了混凝土结构紧密性和完整性。

The addition of rice husk ash improved and concentrated the structure of concrete for its remarkable micro-aggregate filling effect and pozzolanic effect. In this paper,the rice husk ash concrete was prepared with different concentration of rice husk ash. For exploring the optimum concentration of rice husk ash, the durability（ impermeability resistance performance and abrasion resistance performance） and microstructure（ scanning electron microscopy analysis, EDS analysis and nanoindentation analysis） were investigated. The results showed that the addition of rich husk ash improved the durability performance and microstructure of concrete. With the increasing rich husk ash in matrix,the impermeability resistance and abrasion resistance performance were improved significantly.The correspondingly performance improved to the optimum value when the addition of rich husk ash was20%. SEM and EDS analysis showed that no visible pores were shown in SEM micrographs and more CS-H was generated. Nanoindentation analysis showed that the addition of rich husk ash accelerated the rate of hydration reaction and increased the amount of high density C-S-H,which improved the structure of concrete,finally improved the correspondingly performance.