Study Of Construction Waste Regeneration Aggregate Solidified By New Cementitious Material

With the growth of the global economy and population,a large amount of solid waste from construction has been generated.At the same time,the engineering industry consumes a large amount of natural sand and stone resources,which are becoming increasingly scarce.Therefore,effective recycling of construction waste and comprehensive recycling of construction waste aggregate have been paid more attention.Reclaimed aggregate concrete is a kind of green concrete,and it is also an effective way to deal with building waste aggregate.In this paper,the recycled aggregate of construction waste is used as raw material,and a new type of cementitious material is used for consolidation to prepare recycled concrete.The reclaimed aggregate was sampled from a demolished residential building in a research institute in Urumqi,Xinjiang,and the reclaimed aggregate obtained was graded continuously.From the main raw materials such as recycled aggregate and natural aggregate physical indexes and basic performance of comparative research,and from the main composition,reaction mechanism analysis of new type gel were introduced from the aspects such as material,and then used in the working performance and mechanical properties of new cementing material and the performance of ordinary Portland cement.The strength of recycled aggregate concrete was designed to determine the mix ratio of concrete used.According to the test scheme,the experimental group and the benchmark group were set.Through the control test between groups,the change rule and action mechanism of the strength of recycled aggregate concrete were analyzed.The experimental results of the paper are as follows:(1)Compared with natural aggregate,recycled aggregate has significant difference in performance indexes.The strength performance of fully recycled aggregate concrete is also reduced by comparative analysis with ordinary concrete,and there is a certain linear relationship between the reclaimed coarse aggregate content and the strength of recycled concrete.(2)The use of new cementitious materials to consolidate the reclaimed aggregate can provide good cementitious force for the reclaimed aggregate and other aggregates.At the same time,the effect of the new cementitious material is better than that of ordinary Portland cement in terms of basic properties and mechanical properties.(3)The reduction of 28-day compressive strength of recycled concrete is less than 5% when the reclaimed aggregate content is 15%.When the replacement rate further increases,the reduction rate increases first and then slows down.When all the natural aggregate is replaced,the reduction rate exceeds 20%.(4)An appropriate amount of cementitious materials can improve the freeze-thaw resistance of the specimens.At the same time,when the recycled aggregate content is 15%,the recycled concrete prepared has good mechanical strength and freeze-thaw resistance.(5)It is feasible to use recycled aggregate combined with new cementitious materials to prepare concrete,and at the same time,better benefits can be obtained from both economic and social levels,which also promotes the development of resource utilization of construction waste.