Performance Test Of Autoclaved Aerated Concrete Block For Construction Waste

With the transformation of urban villages and the integration of urban and rural areas,the houses built in the 1970 s were largely demolished,resulting in a large amount of construction waste mainly based on abandoned bricks.In order to make the construction waste reasonably absorb and achieve the purpose of protecting the environment,the construction waste was used for the preparation of autoclaved aerated concrete blocks.In the test,the waste bricks,mortar and concrete were mixed into a mixture according to a certain proportion.The variation on dry density and compressive strength of autoclaved aerated concrete blocks under different mixed materials was studied,and the composition of the test mixture was determined.Through the control of the amount of construction waste mixture,lime,cement and gypsum,it is determined that the product performance meets the requirements of A5.0 B06 and the practicality is strong.The control variable method was used to study the variation in various process parameters on the performance of autoclaved aerated concrete block,and the suitable range of each parameter was determined to obtain better performance of autoclaved aerated concrete block.The main research results are as follows:(1)By controlling the temperature of the static stop to maintain the environment,the internal cracking problem of the autoclaved aerated concrete block during the winter preparation process can be effectively solved;(2)Prepare autoclaved aerated concrete blocks under the guidance of 40.2:26.8:4:17:12 ratio of construction waste,fly ash,gypsum,cement and lime.The performance of the products is in line with the national standard.Requirements for A5.0 B06 grade products;(3)The dry density of autoclaved aerated concrete blocked increases in the decrease of 0.075 mm square hole sieve residue ratio and lime content,and the compressive strength decreases with the fineness of construction waste and lime content.Small increases first and then decreases.With the increase of cement content,the dry density and compressive strength of autoclaved aerated concrete blocks show a trend of increasing linearly;(4)Through experimental research,each process parameter has a certain influence on the performance of autoclaved aerated concrete blocks,and there is a suitable range of dosage.The optimum technological parameters for the preparation of autoclaved aerated concrete blocks of construction waste are as follows: construction waste 0.075 mm sieve residue 10%~20%,water to material ratio 0.42~0.46,mold temperature 39°C~41°C,aluminum powder content 0.075%~0.09%,autoclave curing time 6h~7h.