Study on the Performance of Machine-made Sand Concrete Combined Admixture of Limestone Powder and Substandard Fly Ash

摘要

This paper adopted combined admixture of limestone powder and substandard fly ash to prepare the machine-made sand concrete, and studied its performance, compressive strength and micro-properties. The results showed that this kind of machine-made sand concrete owned a good performance, for its 60min slump loss within the range of 15mm to 85mm; the changes in the ratio of limestone powder to low-quality fly ash had little effect on the its compressive strength; with the increase of the ratio between limestone powder and low-quality fly ash, the Ca(OH)_2 diffraction peak also increased; when hydration was up to 120d, the limestone powder was not involved in the hydration reaction.