Effects of packing on compressive behaviour of recycled aggregate concrete

• Published in: Construction & building materials Vol. 157; pp. 757 - 777
• Main Authors: Li, L.G., Lin, C.J., Chen, G.M., Kwan, A.K.H., Jiang, T.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.12.2017; Elsevier B.V
• Subjects: Analysis; Compressive behaviour; Concretes; Packing density; Properties; Recycled aggregate; Recycled aggregate concrete; Wet packing density; China; RS; OPC; Recycled aggregate; FRP; ρbulk; PFA; W/S ratio; Packing density; M; GGBS; ρα; ϕ; V; ρw; SP; Vs; W/C ratio; Rα; ST; uw; Wet packing density; RS/TA ratio; RA; RAC; Compressive behaviour; Recycled aggregate concrete
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.09.097

•Wet packing method was extended to measure packing density of recycled aggregate concrete (RAC).•Workability and compressive behavior of RAC mixes were experimentally investigated.•Strength, elastic modulus, toughness of RAC increase with increasing packing density.•Packing density optimization is a promising way of improving the performance of RAC. It is well known that the packing of particles in concrete has great effects on the performance of concrete, but codified methods for measuring packing density are all carried out under dry condition, which tends to result in loose packing due to agglomeration of the fine particles. Nevertheless, a wet packing method has been developed recently to enable more accurate measurement of packing density. In this study, this wet packing method was extended to measure the packing density of the concrete mix of recycled aggregate concrete (RAC). Furthermore, three groups of concrete mixes with various aggregate proportions and W/C ratios were produced for compression tests. It was found that at given W/C ratio and age, the compressive strength, elastic modulus, toughness and specific toughness of RAC would increase with increasing packing density, indicating that the packing density is a key factor affecting the compressive behaviour of RAC. Hence, packing density optimization is a promising way of improving the performance of RAC.