Physical and mechanical behaviour of recycled concrete under destructive and non-destructive testing

Abstract

Aggregates recycled from construction sites may exhibit slightly inferior characteristics compared to natural aggregates in terms of porosity, friability, and variability. However, it must be acknowledged that although recycled aggregates are currently used only in small proportions for manufacturing concrete, their usage is steadily increasing. It is now widely recognised that the reuse of recycled aggregates in mortar and concrete significantly contributes to the preservation of alluvial aggregates. The valorisation of recycled aggregates in concrete and mortar offers a clear economic advantage in the construction sector. Indeed, the reuse of materials from demolition could be envisaged directly on site or at construction waste recycling and treatment platforms. Additionally, it should be noted that to date, there is no specific standard for measuring the water absorption of recycled aggregates. Regarding the physical properties, the estimation of the absorption kinetics of the recycled aggregates has proved necessary. Moreover, other equally important measurements must be undertaken to determine all the other properties. The results obtained demonstrated that a good correlation exists between the substitution rate and the physical and mechanical properties of the prepared concrete. Furthermore, it was decided to vary the substitution rate of natural sand with recycled sand during the manufacture of concrete according to the following percentages: 25% recycled sand with 75% natural sand, and 50% recycled sand with 50% natural sand.