Application Of Cement Stabilized Recycled Aggregate In Road Base

The proportion of waste concrete in construction waste is the most.Reasonable recycling and utilization of waste concrete can reasonably recycle construction resources,not only reduce the damage of waste to the environment,but also save construction materials,so that construction materials can be recycled.As an important part of construction waste,waste concrete accounts for about 30%-50% of its composition.The waste concrete accounts for more than 30% of the construction waste.The management and reuse of the waste concrete can solve the problems of the transportation,treatment and other aspects of the construction waste in time,so as to reduce the pollution of the waste concrete to the soil.The main characteristics of waste concrete are: large porosity,many cracks on the surface,low compressive strength,so the ability to resist the environmental impact is relatively poor;the main reason is that the low-grade commercial concrete and the high-strength commercial concrete caused by non load are damaged by hardened cement slurry,but the aggregate can still maintain good working performance.The cement mortar and aggregate in waste concrete will generate oxides,such as iron oxide and silicon oxide,when the temperature is very high,but these oxides can be used to produce cement.In the mix design of concrete,the water cement ratio plays a decisive role in the strength of concrete: in the case of the same cement strength grade,the strength of cement concrete is related to the size of the water cement ratio.The smaller the water cement ratio,the greater the cohesion of aggregate,which can make the strength of concrete larger.There are a lot of documents about the treatment of construction waste,in which the treatment technology of waste concrete is less.After the recycling of waste concrete,the waste of resources is reduced,the allocation of resources is optimized,so that the construction waste can not be dumped at will,the environmental pollution is reduced,and the secondary pollution of construction waste is reduced.There are few researches on the application of waste concrete in the construction of road base.In this study,a perfect and practical construction scheme is developed on the basis of laboratory test.The specific research is as follows:(1)This paper mainly relies on the pavement reconstruction project of "a reconstruction project of Yongjin line",taking the waste concrete of this project as the research object,and the recycled aggregate obtained from the waste concrete after processing.(2)The recycled aggregate is compared with the natural aggregate through the tests of screening,water absorption,apparent density,crushing value,soundness,needle slice and mud content.Analyze the test data and relevant specifications between the two.(3)The recycled aggregate is mixed with natural aggregate according to the amount of(0%,25%,50%,75%,100%),and different cement dosage(3%,4%,5%,6%)is added respectively.The standard compaction test is carried out for each mixture,and the optimum moisture content and the maximum dry density of each mixture are measured.Under this condition,the parts are made,and the unconfined compressive strength for 7d is measured.(4)In order to further study the performance of Recycled Aggregate Stabilized by cement,the splitting strength test,flexural tensile strength test,compressive modulus of resilience test and dry shrinkage test were carried out for the mixture with different mix proportion.Through the test data to analyze the use performance of cement stabilized recycled aggregate base,study the use of waste concrete in the pavement base,put forward scientific and reasonable construction methods,quality control standards,and test the test section to verify the road performance.(5)The final purpose of comprehensive evaluation and analysis is to make rational use of construction waste,turn waste into treasure,fully reduce the harm degree of waste concrete to the lowest level,so that it can be used more reasonably in road subgrade engineering,and finally improve the road repair and the maximum use of resources.According to the above test analysis and various studies,the recycled aggregate of waste concrete is determined in water It can be used in mud stabilized macadam base.