Properties Of Cement Stabilized Recycled Aggregates With Crushed Brick

The recycling of construction and demolition waste is an effective measure to alleviate the shortage of natural resources and solve the environmental pollution of construction waste.Some research indicates that the use of crushed concrete for cement stabilized crushed aggregate is a feasible and rational way.Because a certain proportion of crushed bricks are often mixed in the crushed concrete and the strength of the crushed brick is generally lower than that of the crushed concrete,the use of crushed brick for cement stabilized crushed aggregate has a certain impact on the structure.In addition,there is still some difficulty in separating the crushed brick from the crushed concrete.The efficient utilization of the crushed concrete and crushed brick has important significance for the recycling of construction waste.For the lack of research on the influence of crushed brick on the performance of Cement Stablized Recycled Aggregates(CSRA),the investigation of the performance and application of CSRA with crushed brick has a good prospect.The aggregate performance of crushed brick and recycled concrete were studied in the thesis first.Then,the effects of cement content,crushed brick amount and curing age on CSRA were investigated.The following research results were obtained:(1)Both types of recycled aggregates meet the Code requirements of Class II performance for the recycled aggregates.Both types of recycled aggregates can be used as CSRA materials for the road base.(2)With the increasing content of crushed brick,the maximum dry density of CSRA decreases and its optimum water content increases.With the increasing content of cement,the maximum dry density of CSRA increases and its optimum water content is basically unchanged.(3)The unconfined compressive strength,splitting strength and compressive resilient modulus of CSRA decrease with the increase of the amount of crushed bricks,and increase with the increase of cement content and the curing age.(4)Taken the contents of cement and crushed brick as variables,the calculation formulas of the unconfined compressive strength,splitting strength and compressive resilient modulus of cement stabilized recycled aggregate with crushed brick were established,which provided the basis for applying recycled aggregate to the road base.(5)With the increase of crushed brick contect,the antifreeze performance of CSRA is weakened.When the cement content increases,the influence of crushed birck on the frost resistance of CSRA reduces.When the cement content is 5%,the shrinkage strain,water loss rate and dry shrinkage coefficient of CSRA increase with the increase of the amount of crushed brick.