Concrete with multi-recycled crushed concrete aggregates

This paper presents the results of an experimental campaign on the properties of coarse recycled concrete aggregates from different cycles of recycling and their influence on the mechanical and durability performance of multi-recycled recycled aggregate concrete. The recycled concrete aggregates came from three consecutive recycling cycles and were used as partial natural aggregate replacement (25% and 100%, by volume). All specimens were compared with a control concrete with the same mix design, but with natural aggregates only. Generally, the quality of the recycled concrete aggregates is lower than that of the natural aggregates, as a result of the higher old mortar content adhered to original aggregates. An increasing quantity of adhered mortar content was observed as the recycling cycles proceeded. This content stabilized to a point that the recycled concrete aggregates’ properties became predictable as well as its influence to the mechanical and durability performance of the recycled aggregate concrete. The results of this study allowed proving beyond reasonable doubt that the performance of recycled aggregate concrete presents an asymptotical-like decline with increasing number of recycling cycles and progresses in a linear fashion with increasing incorporation of coarse recycled concrete aggregates. Thus, the research is a contribution to the wider use of multiple recycled concrete aggregates, wherein, by knowing the number of generations, the properties of recycled concrete aggregates and of the concrete containing them may be estimated, thereby being capable of being used for a number of construction applications with a good safety level

کلیدواژه ها:

Recycled aggregates ، concrete ، multiple recycling ، mechanical ، durability