不同掺料及水胶比对砌块碳化养护抗压强度的影响

Influence of different admixture and water-cement ratio on compressive strength of block cured by carbonization

为了研究不同掺料和水胶比对碳化砌块的改性作用及拓展以氧化镁和粉煤灰为主要掺料的碳化砌块在西部盐渍土地区的广泛应用,将活性氧化镁和粉煤灰加入到普通硅酸盐水泥中,分析了不同掺量和水胶比对砌块碳化养护后抗压强度的影响,并利用扫描电镜和X射线衍射等手段对其内部结构和碳化机理进行分析研究。结果表明:当活性氧化镁、普通硅酸盐水泥和粉煤灰掺量比值为1∶1∶0.3,且水胶比为0.8时,砌块在适宜条件下碳化养护14d其抗压强度达到最高,同时由砌块的微观形貌分析可知,其内部存在网状且具有粘结性的球形镁质碳酸盐和结晶化合物,有效地填充了砌块内部孔隙及增加了集料之间的粘结性,使砌块在碳化养护过程中不仅提高了耐久性指标,而且为西部地区的应用提供了一定借鉴意义。

In order to study the modification effect of different admixtures and water-binder ratios on carbonized blocks,and to expand the widespread application of carbonized blocks with magnesium oxide and fly ash as the main admixtures in western saline soil regions,active magnesium oxide was used.And fly ash were added to ordinary portland cement,and the effects of different dosages and water-binder ratios on the compressive strength of the block after carbonization were analyzed.The internal structure and carbonation mechanism of the block were analyzed using SEMXRD microscopic experiment.The results shown that when the ratio of active magnesia,ordinary portland cement and fly ash was 1∶1∶0.3,and the water-to-binder ratio was 0.8,the compressive strength of the block was the highest when it was carbonized and cured for 14 days under suitable conditions.At the same time,from the analysis of the microscopic morphology of the block,it can be seen that there were network-like and cohesive spherical magnesium carbonate and crystalline compounds,which effectively filled the pores inside the block and increased the bonding between the aggregate.The property made the block not only improved the durability index during the carbonization curing process,but also provided a certain reference for the application in the western region.