碱当量与模数对碱矿渣混凝土抗压强度的影响

采用英国北爱尔兰地区高炉矿渣、水玻璃等原材料制备碱矿渣混凝土,研究水玻璃碱当量和模数对碱矿渣混凝土性能的影响。结果表明:碱矿渣混凝土的坍落度随碱当量增加而增大。碱当量较小时(4%和6%),水玻璃模数对碱矿渣混凝土坍落度影响不明显;但当碱当量增大至8%时,碱矿渣混凝土坍落度明显随模数增加而增大。以3 d抗压强度为指标,水玻璃碱当量不应低于6%,最佳模数为1.0左右;以28 d及以后抗压强度为指标,最佳碱当量及模数则分别为6%和1.5左右。碱矿渣混凝土抗压强度随养护龄期的延长呈对数增长,28 d抗压强度均达到91 d抗压强度的75%以上,28 d后抗压强度发展缓慢。

Influence of alkali concentration and modulus on compressive strength of alkali activated slag concrete

Alkali activated slag(AAS) concretes were manufactured by using raw materials such as blast furnace slag from Northern Ireland of UK and water glass. Influence of alkali concentration and modulus of water glass on properties of the AAS concretes was studied. The results show that slump of AAS concretes increased with the increase of alkali concentration. Modulus had no significant influence on the slump of AAS concretes when it is relative small(4% and 6%). When alkali concentration was 8%,slump of AAS concretes increased with the increase of modulus. When 3 d compressive strength of AAS concretes was considered,alkali concentration of water glass should not be lower than 6%,and the optimum modulus was around 1.0. While regarding to the compressive strength at 28 d and afterwards,the optimum alkali concentration and modulus were 6% and 1.5,respectively. With the increase of curing age,compressive strength of AAS concretes increased in a logarithm mode. Their 28 d compressive strength could reach to 75% of their 91 d counterpart. After 28 days,compressive strength of AAS concretes increased slowly.