Abstract：Nowadays, machine-made sand is the most common material of replacing river sand, but machine-made sand has some problems including uneven gradation, excessively high stone powder content, energy consumption during production and environmental pollution. In view of the abundant desert sand resources in the western region of China, the mechanical test on Desert sand and Machine-made sand Concrete (DMC) was carried out here, and the influences of different desert sand replacement rates on the strength and elastic modulus of concrete were analyzed. The strength and elastic modulus of DMC gradually increased with its age, and the axial compressive strength of DMC at 14 and 28 days of curing showed a trend of increasing at first and then decreasing with the increase of desert sand replacement rate, with the peak value of the trend corresponding to the desert sand replacement rate of 20%. It was found experimentally that the desert sand replacement rate had a greater influence on the compressive strength of DMC than the elastic modulus of DMC. Based on the compressible bulk theory of concrete and considering the changes in the bulk density of desert sand and machine-made sand as well as the difference in geometric appearance between machine-made sand and desert sand, the concrete binary mixture bulk model was extended to the physical parameters of fine aggregate bulk, and the prediction model of DMC compressive strength with good model accuracy was established. Through case study, on the premise of ensuring that the station structural material had good mechanical properties, when 20% of DMC was used, the carbon emissions studied were relatively low due to the reduced use of machine-made sand for fine aggregate.
王雪艳 刘明辉 刘萱 贾思毅 徐舟. 沙漠砂+机制砂混凝土力学性能及碳排放研究[J]. 土木工程学报, 2022, 55(2): 23-30.
Wang Xueyan Liu Minghui Liu Xuan Jia Siyi Xu Zhou. Study on mechanical properties and carbon emissions of desert sand and machine-made sand concrete. 土木工程学报, 2022, 55(2): 23-30.
