固硫灰-激发剂二元干混砌筑砂浆研究

Preparation of Dry-mixed Masonry Mortar Using CFBC Ashes-activator Binary System

固硫灰是循环流化床锅炉燃煤固硫产生的工业废渣,具有自硬性、火山灰活性和膨胀性等特性,将其与碱性激发剂复合作为胶凝材料制备建筑砂浆将有望降低水泥用量、提高砂浆保水率和改善砂浆收缩。作者利用固硫灰-激发剂作为二元复合胶凝材料制备干混砌筑砂浆,研究碱性激发剂掺量、固硫灰细度、保水增稠材料掺量、胶砂比和砂级配对砂浆性能的影响。实验表明:粉磨至一定细度的固硫灰中掺15%碱性激发剂、胶砂比为1∶2、砂级配为1∶1时可制备28d抗压强度达到10.7MPa的干混砌筑砂浆,砂浆保水率94.7%、凝结时间6.9h、2h稠度损失率14.1%,各项性能均符合GB/T 25181—2010的要求。

Circulating fluidized bed combustion （CFBC） ash is an industrial residue for good pozzolanic, self-hardening and expansion properties. That using CFBC ash with activator composite as a cementitious material to prepare building mortar has the potential to reduce cement usage, enhance water retention of fresh mortar and improve volume stability of mortar. This study examined the feasibility of manufacturing dry-mixed masonry mortar using CFBC ash with activators composite. The parameters affecting the performance of the mortar, such as usage of activator, fineness of CFBC ash, dosage of water-retaining agent, binder-sand ratio and gradation of sand, were investigated. Experimental results indica-ted that performances of dry-mixed masonry mortar which was prepared according to an ingredient design （85% CFBC ash ground to a certain degree of fineness, 15% activator, binder-sand ratio of 0. 5 and sand ratio of 0. 5） satisfied specific requirements of GB/T 25181-2010. Performances of mortar included compressive strength of 28 days up to 10. 7 MPa, water-retention rate of 94. 7% setting time of 6.9 h and consistency loss rate of 2 h up to 14. 1%.