关键词: 灌注桩, 机制砂, 混凝土, 强度, 耐久性

Abstract: The experience of applying manufactured sand in the highway construction in Gansu Province is still rarely reported. According to the investigation of manufactured sand from many venders in Gansu Province, a comparative study between the manufactured sand concrete and the natural sand concrete in the strength and the durability was investigated. The results show that: The 28-day strength of the manufactured sand concrete can reach the same grade as that of the natural sand concrete for C40、C50、C60, and the strength of manufactured sand concrete is slightly higher than that of natural sand concrete. In terms of the durability index, the dry shrinkage rate of C40~C60 with manufactured sand concrete is lower than that of the natural sand concrete. Under the same grade of frost resistance, the relative dynamic elastic modulus of the manufactured sand concrete is greater than that of the natural sand concrete. The fluoride and carbonation resistance in the manufactured sand concrete are basically at the same level as those of the natural sand concrete.

Key words: bored cast-in-place concrete pile, manufactured sand, concrete, strength, durability