含钙地质聚合物的制备与性能研究-结构工程专业论文.docxVIP

哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 - - PAGE VI- -III- -III- Abstract This thesis studies the early setting performance of high calcium fly ash geopolymer paste, mechanical peoperties, durability and microstructure of geopolymer containing calcium are investigated.High calcium fly ash, or low calcium fly ash mixxing with Ca (OH)2 or slag were used to prepare geopolymers. The curing technique of geopolymer was mastered and the effects of the curing technique, the water fly ash ratio, the calcium content and the variety of calcium additives on the properties of geopolymer were investigated. The condensation process and the setting time of geopolymer paste were measured by Vicat in the different conditions. The main factors were temperature, water fly ash ratio and the surface with or without the covered film, in which the factors,the temperature has the greatest effect on the condensation. The experimental data shows that the setting time is between 1410 min and 1485 min at 25℃ and the setting time is between 80 min and 90 min at 60℃. The more temperature increase, the faster the condensation speed of geopolymer is. In the slag-low calcium fly ash geopolymer mortar, with the slag content increases, the fluidity decreases and the bulk density increases. The strength of high calcium fly ash geopolymer mortars are growing faster in the standard curing conditions, but the strength is dropping at the early days and the growth rate of the strength is slow in the steam curing and oven curing, and the compressive strength at 28d is almost equal in the different curing system as the water-fly ash ratio increase, its strength gradually decrease. It means that high calcium fly ash geopolymer mortar should choose the little water fly ash ratio in standard curing system for conservation. In the slag-low calcium fly ash geopolymer mortar when the slag content increases, the strength also increases. However, in the two curing conditions, low calcium fly