Experimental Study On The Property And Optimization Of Autoclaved Aerated Concrete

With environmental compatibility and sustainability becoming increasingly important issues in the construction industry,Aerated concrete as a kind of lightweight wall material received attention again, Its unique combination of superior strength, lightweight, heat insulating and processability makes the construction process much more eficient, energy saving and environment protecting, so aerated concrete is widely used in multi-story and high-rising buildings. However, due to AAC's unique cell structure and absorbing water property, many quality problems have emerged, such as: unmatching of strength and strength grade, deformation, cracking and declining in heat preservation etc. These problems seriously affect the visual impression and utilization and make against the further development of wall materials. Aiming at this circumstance, this paper has made a completely systemic study on the property of AAC and put forward solutions.Firstly, this paper analysed the influence of pore structure, porosity and water content on compressive strength, studies on compressive strength of different water content, tensile strength, relationship of stess-strain, static modulus of elasticity, drying shrinkage and relational expressions of water content and each mechanic property have been obtained by regression calculation, on this basis, the safe quantity of drying shrinkage and safe water content for construction have also been calculated. At the same time, the mechanic model of restrictive shrinkage between concrete and mortar has been established at the first time. Combining experimental analysis, this paper bring forward some doubts on Chinese standard and has given improvement suggestion. All these have certain instructive significance for the improvement of AAC's performance.Secondly, this paper tested on the main thermal index of AAC and evaluated its heat preservation property. Different equilibrium moisture content under different relative humidity has been got through studying on the moisture absorption property. This paper also studied the process of moisture absorption and discharge of AAC surface, the results showed that AAC has a very good self-adjustmentfunction of moisture.Finally, experiment has been made by using additive in AAC slurry to improve the property of AAC,so as to popularize the AAC.