An Experimental Study On Mechanical Properties And Bond Property Of Self-compacting Lightweight Aggregate Concrete

With the rapid development of economy and the improvement of people's quality of life,the total amount of the current social construction in society has been rising,and the demand for concrete which is the basic building material in the field of construction is also increasing as well.However,on grounds of the disadvantages of concrete,such as large dead weight,large shrinkage,low tensile strength and difficult to vibrate in complex structure,it is more and more difficult to meet the needs of buildings now.The self-compacting lightweight aggregate concrete is a new building material with the properties of lightweight,high strength and good fluidity,which has been paid more and more attention.In this paper,based on the experimental study of the team,we choose 900 high strength shale ceramsite as lightweight aggregate,and use the absolute volume method to design the mix proportion.The optimum mix ratio of self-compacting lightweight aggregate concrete with the strength grade of C50 was determined.The mixture of the slump flow is 620?660mm and the apparent density is 1896kg/m~3.The cube compression test was carried out with 48 standard cube specimens;the axial compression test was carried out with 48 prism specimens;the split tensile test was carried out with 18 standard cube specimens;the bending tests were carried out with 18specimens of small beams,Their failure modes are studied.The cubic compressive strength,axial compressive strength,splitting tensile strength and flexural strength of self-compacting lightweight aggregate concrete have been obtained,and based on the statistical analysis of the data.we obtained the relationship between the compressive strength and the axial compressive strength,the tensile strength and the experimental value and the standard value are obtained.The elastic modulus and Poisson's ratioare were obtained by the tests of 18specimens.The elastic modulus of C50 self-compacting lightweight aggregate concrete was 380MPa,and the Poisson's ratio was 0.17Based on the tests of 27 specimens,the bonding properties of self-compacting lightweight aggregate concrete and steel bar have been studied.We analyzed the influence of relative thickness of protective layer on the failure mode of the specimen and obtained the linear regression equation between the relative bond strength and the thickness of the protective layer(?);drawt-s curve.We also studied the failure characteristics of each stage in the process of failure.