Research On The Preparation And Properties Of High Fluidity Brickbats Aggregate Concrete

At present,with the rapid development of Chinese construction industry,the demand for building materials is growing,especially the concrete.As the natural aggregate is over-exploited,and the abandoned concrete is not fully utilized,the construction waste has become an unavoidable factor in the destruction of the ecological environment.In the abandoned building materials,the waste clay brick has a larger proportion.If the waste clay brick is used as aggregate to realize recycling,it has a large degree to solve the problems of the occupation of waste building materials,and the environment pollution.It can also alleviate the scarcity of concrete aggregates.The research about brickbats aggregate and brickbats concrete is still in its infancy in China.And there are few research results about the preparation methods and mechanical properties of the high fluidity(the large fluidity of slump greater than 180mm)brickbats aggregate concrete.In this paper,the research of the pretreatment methods of the reinforced brick aggregate is carried out,and the preparation methods and mechanical properties of the high fluidity brickbats aggregate concrete are also studied.The effects of different factors on the mechanical properties of the large fluidized brick aggregate concrete are further studied by the orthogonal test,and the best mixture ratio is determined.The feasibility of non-destructive testing of high fluidity brickbats aggregate concrete is explored.The main contents of this paper are as follows:(1)Mechanical crushing,screening,washing and drying of brickbats aggregate,and fortified pretreatment in different ways,test the apparent density,water absorption rate and crushing index of brickbats aggregate,analyze the effect of different pretreatment methods on the apparent density,water absorption and crushing index of brickbats aggregate;(2)Use untreated brickbats aggregate and pretreatment brickbats aggregate to replace some or all natural gravel aggregate to prepare high fluidity brickbats aggregate concrete and calculate the initial mix ratio;analyze the influence of untreated brickbats aggregate and pretreated brickbats aggregate on the performance,28d compressive strength,splitting tensile strength and axial compressive strength of high fluidity brickbats aggregate concrete mixture;(3)The orthogonal test is used to study the influence of the replacement rate of aggregate,the content of polypropylene fiber,the replacement rate of mineral powder and the content of silica fume on the working performance and mechanical properties on the high fluidity brickbats aggregate concrete.The influence of different factors on the compressive strength of concrete is analyzed.The best mixture ratio is determined through the range analysis and analysis of variance in the experimental range;(4)Measure the ultrasonic and the rebound value of high fluidity brickbats aggregate concrete,combined with the compressive strength value,using regression analysis method,establish the measuring equation.