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Project

The use of high-quality recycled concrete aggregates in precast non-prestressed and prestressed concrete

Nowadays, the use of recycled concrete aggregates (RCA) is mainly limited to non-structural concrete, although they have the possibility to be used in higher-valued applications. One of the main reasons for not using RCA in structural applications is the doubt to produce concrete with high and consistent performance. RCA have specific characteristics that influence the mechanical properties and durability aspects of concrete. RCA consist of the original aggregate, surrounded by attached mortar. This generally weaker and more porous attached mortar is considered one of the main reasons for the lower mechanical properties of concrete with RCA. Another reason for a conservative attitude towards RCA use in concrete is the heterogeneity of RCA. A proper classification system of different RCA types is necessary to reduce the heterogeneity and use them according to their distinct characteristics. RCA with a normal quality should be used in non-structural applications, while the high-quality RCA have the potential to be used in structural concrete with higher strength. The high-quality RCA can reduce doubts about their use in structural concrete because of their high and consistent quality. The precast industry has already shown interest in using high-quality RCA in their products, but a lack of information on the specific influence of RCA withholds its implementation in precast concrete. Precast structural concrete demands additional requirements compared to non-structural concrete. The effect of RCA on early-age behaviour and variability of the mechanical properties of concrete, bond properties between reinforcement and RAC, and time-dependent properties is tested and analysed in this PhD research.

Date:10 Jan 2017 →  12 Oct 2021
Keywords:recycled concrete aggregates, structural use, precast concrete, pre-stressed concrete
Disciplines:Construction engineering, Earthquake engineering, Geotechnical and environmental engineering, Water engineering, Wind engineering
Project type:PhD project