Experimental Study On Physical Mechanical Properties Of Straw MOC Concrete

In this paper,a new production process is used to combine the waste straw after mechanical treatment with magnesite material in which add a suitable proportion of mineral filler and admixture to form a new kind of straw MOC concrete.Its purpose is to break through the shortcomings of traditional straw building materials which has lower straw addition and lower compressive strength,and make full use of straw insulation performance in rural housing,build green ecological building,the benefit of the people.In this paper,the research status of traditional straw concrete and the reasons for not being popularized in large scale are analyzed.A special device was designed to develop a new straw concrete.The raw material composition of the straw concrete was determined,and the treatment and selection of the straw,the production of the brine and its concentration,the preparation and proportion of the cemented material,the performance of magnesite cement were explored.A perfect process of making straw concrete specimen was formed.Then,three orthogonal experiment group which includes 600 kg·m-3,800 kg·m-3 and 1000 kg·m-3 density classes was designed to study the influence of straw content,binder ratio and sand content on the compressive strength,elastic modulus and dry density of straw concrete.And the results of orthogonal test were systematically analyzed which includes extreme analysis,point graph analysis,variance analysis.The optimal mix ratio of the three test groups was determined.Accord ing to the test results,the compressive strength of low density straw concrete was analyzed,and the straw concrete with 1600kg·m-3 and 1800kg·m-3 density was designed to meet the requirements of load-bearing block strength..Then the compressive failure mode of the straw concrete cube specimen is analyzed,and the stress-strain curve is drawn.The elastic modulus is calculated according to the stress-strain curve.The stress-strain curves of concrete specimens with different density of straw are analyzed synthetically and the deformation law is studied.Then,the compressive strength,elastic modulus and dry density of straw concrete with different density grades were compared with those of other concrete,which proved the superior performance of straw concrete.Finally,the thermal conductivity and softening coefficient of straw concrete with different density grades were tested.It proves the excellent insulation performance of the straw concrete and puts forward the improvement scheme for the shortcomings of the poor water resistance of the straw concrete.The straw concrete prefabricated medium block and light steel skeleton-straw concrete mixed structure wall were designed.And the pseudo-static testing of the wall is carried out,which proves that the concrete block has excel ent seismic performance when building the wall.