Abstract：Natural sand, the main source of concrete fine aggregates, has been over exploited, leading to resource depletion and environmental damage. Using manufactured sand instead of natural sand as concrete fine aggregate is one of the solutions. However, the stone powder content of manufactured sand is difficult to control in actual engineering. A proper amount of stone powder can improve the gradation of concrete, while improper stone powder content will reduce concrete strength and increase strength dispersion. The specification of “Sand for Construction” stipulates that the content of machine-made sand and gravel powder should not be higher than 10%. This paper studies the effect of calcium sulfate whiskers (CSW) on the modification of the stone powder content of manufactured sand concrete: The mechanical property test of manufactured sand concrete mixed with calcium sulfate whiskers (5kg/m3) under different stone powder content (10%, 15%, 20%) was designed. The mechanical property test of the polypropylene fiber (PPF) was carried out as a comparative test. The results showed that the mechanical properties of the specimen group with 10% stone powder without fiber were significantly higher than those with 15% and 20% stone powder. After mixing CSW and PPF, the mechanical properties of the specimen group with 15% stone powder are the best, and the modification effect of CSW is more obvious than that of PPF. Based on the compressible accumulation theory and the modification effect of CSW on high-stone-silt machine-made sand concrete, a model of the strength of CSW-modified high-stone-silt manufactured sand concrete is established, and the model parameters are fitted through the test results.
刘明辉 王雪艳 刘萱 贾思毅. 硫酸钙晶须对机制砂混凝土中石粉#br#
的改性作用研究[J]. 土木工程学报, 2021, 54(5): 56-64.
Liu Minghui Wang Xueyan Liu Xuan Jia Siyi. Study on modification effect of calcium sulfate whiskers on#br#
stone powder content of manufactured sand concrete. 土木工程学报, 2021, 54(5): 56-64.
