Research On The Performance And Application Of Recycled Coarse Aggregate From Waste Concrete In Urumqi

The research from the Xinjiang Uygur Autonomous Region NaturalScience Fund Project recycled aggregate grading and classification of concrete,project number:2012211A005.Since China’s reform and opening up, along with economic development,infrastructure construction, will have a large amount of construction waste every day.The waste concrete accounted for a large proportion, if the waste concrete inconstruction waste to recycling, can meet the needs of a large part of the project, theconstruction waste disposal problems can be resolved. Production of Xinjiang inUrumqi city in2012has reached12820800tons of solid waste, the waste concreteaccounted for40%of the total to50%, the Xinjiang area every year waste concreteemissions is considerable. Study of waste concrete is a waste recycling process, theconflict will solve the fundamental cause pollution to the environment and thedevelopment of the industry.Given the aggregate regional differences, and different regions of theenvironment on the original concrete also produces different results in a performanceof waste concrete recycled aggregate are not the same, subject to the detection of thetest results of various important evaluation index of recycled coarse aggregate inXinjiang area, and in accordance with the current national standard of recycled coarseaggregate, Xinjiang area for preliminary classification; for different recycled coarseaggregate for cleaning, and the determination of the basic properties of recycledcoarse aggregate, the conclusion does not influence the quality of its performance inthe cleaning process, and for the preparation of recycled coarse aggregate concretequality will be enhanced, and suggested that the recycled coarse aggregate washing3times in advisable;Quantitative test on aging mortar cement content of recycled coarse aggregatesurface by heat treatment method, explore the relationship between the waste concrete recycled coarse aggregate surface attachment content and water absorption of mortar,mortar adhesive content and apparent density relations, the relationship betweenapparent density and water absorption rate; and find out the recycled coarse aggregatesurface attached mortar content and recycled concrete added with the relationshipbetween water;Subject to common concrete mixture ratio design method of C30of recycledcoarse aggregate concrete mix ratio design, through the test cube compressivestrength test, the effects of water cement ratio is0.45,0.48,0.50and0.55differenttypes of recycled coarse aggregate concrete workability and compressive strength.Taking into account the recycled water absorption characteristics of coarse aggregate,directly apply the ordinary concrete mix design method, can improve the compressivestrength of recycled concrete, but reduced its work performance, therefore in the mixdesign of additional water design, find out the relationship between additionalrecycled coarse aggregate surface mortar water use and attachment content, differentadditional water use for the influence of recycled coarse aggregate concreteworkability and compressive strength, according to the test results and thecomprehensive and literature data, obtains the C30regeneration of optimum water ashconcrete coarse aggregate ratio is0.45, the optimal additional water for net water use10%. Through the test analysis and research, the recycled coarse aggregate concretehas the construction performance and better mechanical properties, after a simpletreatment can be used for ordinary reinforced concrete structure.