探讨了以河道淤积泥沙和农业废料稻壳灰为主要原料的新型胶凝材料的可行性。试验研究了稻壳灰和石灰掺量、水玻璃用量及养护龄期对试件抗压强度和软化系数的影响,并用扫描电子显微镜观察了试件的微观形貌。试验结果表明:养护龄期、稻壳灰掺量及水玻璃用量对试件的抗压强度和耐水性能影响明显。试件抗压强度和软化系数呈现随养护龄期、稻壳灰掺量及水玻璃用量增加而增长的趋势,其中稻壳灰掺量对试件抗压强度的影响最为明显,水玻璃次之,石灰掺量影响最弱。试件56d抗压强度最高可达15.30MPa,相应软化系数为0.93。扫描电镜观察(SEM)结果表明:淤泥一稻壳灰基胶凝材料的反应产物主要是均匀致密的絮状凝胶物质(水化硅酸钙凝胶C—S—H)和少量的CaCO3晶体。
In this paper, experimental studies of a new kind of cementitious materials by using sludge and rice hush ash as the raw materials and sodium silicate as activator are introduced. The effects of the rice hush ash, lime content, sodium silicate dosage and curing age upon the mechanical properties and water resistenee of the cementitious materials are analysed, and the scanning electron microscope (SEM) is used to observe the microstructure of the new cementitious materials. The experiment results show that the mechanical strength and water resistence of the cementitious materials are impacted notably by the curing age, rice hush ash, lime content and sodium silicate dosages, and that the influence factors in order of importance are rice hush ash dosage, sodium silicate dosage and lime dosage. The maximum compressive strength of the specimen was up to 15.30 MPa and the corresponding softening coefficient was 0. 93 at 56 days. The observed results of the scanning electron microscope (SEM) show that the flocculent reaction products based on silt-rice husk ash cementitious materials are mainly uniform dense floccule gel (hydrated calcium silicate gel C-S-H) and a small amount of the block crystal CaCO3.