Compressive strength and microstructural analysis of recycled coarse aggregate concrete treated with silica fume: Fid-Bau Portal

Compressive strength and microstructural analysis of recycled coarse aggregate concrete treated with silica fume

Zhu, Lihua / Ning, Qiujun / Han, Wei / Bai, Leilei

Highlights • RCA was treated with SFC paste. • The slump and compressive strength of TRCAC was improved significantly. • The failure mode and compressive strength of TRCAC were similar to those of CC. • The ITZ thickness of RAC was reduced, and the microstructure was improved.

Abstract Recycled coarse aggregate¹ 1 Recycled coarse aggregate: RCA. (RCA) was treated with silica fume cement² 2 Silica fume cement: SFC. (SFC) paste. Subsequently, specimens of two types of concrete were prepared: one with treated RCA³ 3 Treated recycled coarse aggregate: TRCA. (TRCA) and another with natural coarse aggregate⁴ 4 Natural coarse aggregate: NCA. (NCA) based on conventional concrete⁵ 5 Conventional concrete: CC. (CC) mixture designs. The slump, cubic, and prism compressive strengths of the two concretes were compared and analyzed. Moreover, the microstructures of these two concretes were qualitatively analyzed using scanning electron microscopy⁶ 6 Scanning electron microscopy: SEM. (SEM) and energy-dispersive spectroscopy⁷ 7 Energy-dispersive spectroscopy: EDS. (EDS). The results showed that the mechanical performance of TRCA concrete⁸ 8 Treated recycled coarse aggregate concrete: TRCAC. (TRCAC) was improved significantly. The enhanced strength of this recycled aggregate concrete⁹ 9 Recycled aggregate concrete: RAC. (RAC) is mainly due to the incorporation of silica fume, which can improve the quality of RCA and reduce the thickness of the interfacial transition zone¹⁰ 10 Interfacial transition zone: ITZ. (ITZ) of RAC.