关键词: 航道整治;矿粉掺量;废弃超细砂;砂混凝土;力学性能

Abstract: Waste ultra-fine sand from waterway regulation was used as main raw material to prepare sand concrete by vibrating forming.An initial study on the effect of slag content on the density of sand concrete dry mixture was conducted by optimizing the maximum packing mass volume of dry mixture,then 7 d,14 d and 28 d compressive strength,tensile strength and compressive strength after softening were tested to determine the influence of slag content on the performance of sand concrete.X-ray diffraction(XRD) technique was used to analyze sand concrete specimens.The result shows that the best mixing ratio of this sand concrete is 75.3% of waste ultra-fine sand,16.5% of cement,8.2% of slag with water/binder ratio of 0.38 and water reducing agent dosage of 0.5%.The optimal 28 d compressive strength, tensile strength and compressive strength after softening of the sand concrete can be achieved and the XRD pattern indicates that there are quite a lot of hydrate products such as calcium silicate hydrate(C-S-H) gel and ettringite in sand concrete specimens.For the areas with rich waste ultra-fine sand resources but lack of ordinary sand materials for concrete,the study provides a technical approach for the utilization of waste ultra-fine sand from waterway regulation, having significant economic value and broad application prospects.

Key words: waterway regulation;slag content;waste ultra-fine sand;sand concrete;mechanical property