The Mechanical Properties Of The Composite For Construction Waste And Different Reinforcement

With the rapid development of China’s economy,hundred millions of construction waste will be generated every year.The treatment of construction waste is air storage or direct landfill,which not only takes up a large amount of land resources,but also produces many problems in the process of transportation and stacking.At present,construction waste has been widely applied in geotechnical engineering as roadbed filler,and has achieved good results.In this paper,a series of researches on reinforced soil of construction waste are carried out through direct shear test and indoor large-scale triaxial test.For the construction and demolition waste concrete of different contents mixed with sand as a subbase filler,through a large scale direct shear test equipment on geosynthetics,there is a shear characteristic analysis on the composite soil of different contents and laying the triaxial geogrids,geocell reinforcements after reinforcing.The results show that the concrete contents is only 40% or 60%,the shear strength can be improved,and the highest shear strength reach 1.5 times more than that of pure sand.According to the interface shear strength coefficient,Too much or too little waste concrete contents will weaken the overall shear performance;In general,when a certain waste concrete contents is reinforced with geosynthetics compositely,composite reinforcement effect of geocell is better than that of triaxial geogrids,and when the waste concrete of 60% content is reinforced with the geocell,and the shear strength of which is 1.6 times more than that of pure sand,which means the shear performance is excellent.Through the large-scale triaxial test,the strength characteristics of different construction waste and sand mixed soil are compared,and the reinforcing effect of composite reinforcement with different materials is analyzed.In this paper,influence of different construction waste contents on the overall properties of samples,effect of composite reinforcement on different kinds of reinforcement and different construction waste samples,and the influence of the reinforcement spacing on the overall strength of the samples are mainly comparative analyzed.The experimental results show that construction waste can increase the cohesion and internal friction angle of specimens.The overall performance of the 60% construction waste is better than that of the 40% construction waste.Specimens with different kinds of reinforcement have obvious dilatancy,the overall performance of the sample can be effectively improved by using of reinforcement.The overall performance of 60% construction waste and the spacing between geocell and geocell is 20 cm is best.The lateral deformation of geogrid reinforced specimen is smaller than others by containing 40% construction waste and two layers of reinforcement;the lateral deformation of geocell reinforced specimen is smaller than others by containing 60% construction waste and two layers of reinforcement in terms of restricting deformation of specimen.When the reinforcement spacing of specimens is 20 cm,the overall performance used reinforcement and construction waste in the sample together is best.Finally,according to the test results,6Duncan-Chang model parameters of reinforced soil for building waste are solved.