Study On The Aggregate Influence Of Freeze-thaw Rasistance Of Regenerative Insulation Concrete And Mechanism Analysis

Recycled aggregate thermal insulation concrete(RATIC)on the basis of the solution to building energy efficiency at the same time meet the requirements of bearing capacity of structure,the response should also comply with the requirement of energy conservation and emissions reduction in China.RATIC is presented in this paper the current research status,according to the domestic freeze-thaw cycle and mesoscopic test standard requirements,the recycled aggregates and determine for the study of the basic factors of thermal insulation aggregate,dosage of exploring different factors of RATIC antifreeze performance and the influence law of freeze-thaw deterioration mechanism,and set up the normal concrete(NC)as the control group,and the degradation mechanism of both antifreeze performance test analysis.The main research contents and conclusions are as follows:(1)RATIC compared with NC antifreeze performance study.RATIC and NC in the freeze-thaw conditions,the same comparison of surface damage,the relative dynamic elastic modulus,the change law of quality loss rate and compression strength RATIC and the superiority of NC antifreeze performance.The results of the study are as follows: NC after freezing and thawing cycle RATIC compared to its surface damage is more serious,RATIC relative dynamic elastic modulus,mass loss loss rate and compression strength attenuation amplitude is lower than that of NC,freezing and thawing cycle damage serious than RATIC of NC.(2)To replace rate of recycled aggregates for the study of factors,explore RATIC antifreeze performance change rule.Selected recycled aggregate rate was 0%,30%,50%,70% and 100%,the freeze-thaw cycle test was carried out on the RATIC respectively,and the compressive strength test,determine the RATIC antifreeze performance of recycled aggregate are studied.Test results show that the increase of recycled coarse aggregate content leads to RATIC antifreeze weakened gradually,the performance of the specimen surface damage degree increases,the compressive strength value attenuation level also will increase.Relative dynamic elastic modulus for reference to measure RATIC antifreeze performance change rules,the results show that along with the increasing level of recycled coarse aggregate content,the corresponding RATIC relative dynamic modulus of elasticity attenuation amplitude all showed a trend of rising,thus come to the conclusion that recycled coarse aggregate content on RATIC antifreeze level presents negative effects.(3)With insulation aggregate(vitrified beads)content for the study of factors,experimental study on RATIC frost resistance.Will 1 square concrete adding 1.3 vitrified beads content positioning datum,selected on the basis of thermal insulation aggregate content is 0%,30%,50%,70%,50%,and according to the proportion adjusting water consumption,ensure the effective water cement ratio during different insulation aggregate are held constant,the above five kinds of mortar under the RATIC of freeze-thaw cycle and compressive strength test.Experimental results show that under different thermal insulation aggregate content(since)RATIC resistance to freezing and thawing damage ability is not a linear relationship,70% of thermal insulation aggregate mortar RATIC antifreeze performance best.And different insulation aggregate mortar(since)the RATIC after 300 times of freeze-thaw cycle,compressive strength value of the corresponding reduction of 90%,86%,79%,86% and 79%.(4)RATIC mesoscopic experimental study.With insulation aggregate and recycled aggregate as the research factors,factors of different content of RATIC specified freeze-thaw cycle in the state of the corresponding CT scanning test specimens.Test results show that the freezing and thawing cycle weakens RATIC internal bonding capacity of aggregate and cement mortar,the specimen within the tiny cracks,mainly of parts of the crack and the interface between aggregate and cement mortar.And with the deepening of freeze-thaw damage,specimen internal crack number,width,crack area tend to rise in geometry,such as when the reach a certain number and crack width,specimen loss of overall performance,flaking and fracture specimens.