Study On The Performance Optimization Of Sand Autoclaved Aerated Concrete And Supporting Mortar

Energy conservation is the essential ingredient of green building and the important link of sustainable development in today’s construction industry.Therefore,aerated concrete featured with low weights,high strength and environmental protection will become the most important constituent part of green buildings.In order to further promote the application of aerated concrete,this article was focused on optimization of aerated concrete through the exploitation of alternative siliceous materials,addition agent and surface mortars.1)Fine-grained quartz sand was replaced by rice husk ash to improve the silicon content in SAAC raw materials and the water requirements in raw materials.Besides,the utilization of rice husk ash can reduce the dry density and strength of foam concrete block as well as the production cost,and realize the recycling of crop by-products.The optimal dosage of rice husk ash was found to be 50% of fine-grained quartz sand.2)Three moisture repellents can significantly reduce the water absorption and improve the compressive strength of SAAC in a certain degree within the scope of appropriate dosage.Among them,hydroxylloxane showed the best effect,the saturated water absorptivity of SAAC is only 2.45% and the strength can be increased by 15% when the content of hydroxylloxane was 0.8%.Calcium stearate and potassium methyl silicate showed negative effect on the heat preservation and insulation performance of SAAC.On the contrary,hydroxylloxane can decrease the thermal conductivity coefficient of SAAC within the additive amount of 0.6% and therefore improve the heat preservation and insulation performance of SAAC.Hence,hydroxylloxane is an ideal modifier for SAAC with theappropriate content of 0.4 to 0.8%.3)Based on the influence of M/P value on the compressive strength and flexural strength of MPC surface mortar,3 was determined to be the most appropriate M/P value.Polyphosphate retarder can effectively prolong the setting time of MPC surface mortar and benefit the control of operation time and curing time of bonding materials.In addition,polyphosphate content in practical operation was determined to be 4%.Based on the influence of floating beads content on the bonding strength,water absorption and water retention of MPC surface mortar,the optimum content of floating beads was determined as 50% in this experiment.Based on the influence of cellulose ether content on the working performance,mechanical properties and thermal insulation performance of MPC surface mortar mixture,the optimum content of cellulose ether was determined to be 3 ‰.