Effects of GH admixture on the early strength of fly ash concrete and mortar

Abstract

The enhancement effects of GH admixture on the early strengths of fly ash concrete and mortar were studied, and the mechanism was analyzed by X-ray diffraction (XRD) and scanning electro microscope (SEM). Experimental results show that, by the incorporation of GH admixture, both of cement hydration and pozzolanic reaction of fly ash are accelerated, the strengths of fly ash concrete and mortar are enhanced noticeably, especially the early strength. With a mixture design of 200 kg/m³ OPC (Ordinary Portland Cement), 200 kg/m³ fly ash and 50 kg/m³ GH admixture, the strength of concrete at 1 d, 3 d and 28 d reaches 25 MPa, 50 MPa and 70 MPa respectively.

Keywords

building materials / fly ash concrete / GH admixture / strength / microstructure

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