自密实机制砂混凝土耐久性试验研究

Experimental Study on the Durability of Self-compacting Machine-made Sand Concrete

通过以机制砂和天然砂为细骨料来制备自密实混凝土,通过机制砂内石粉质量分数的不同及自密实混凝土水灰比的不同来进行试验研究,经过试验发现机制砂自密实混凝土的流动性比天然砂自密实混凝土流动性差,但是机制砂自密实混凝土的抗压强度高于天然砂自密实混凝土。石粉质量分数的多少会对自密实混凝土的耐久性能及力学性能产生影响,石粉质量分数的增多会使得自密实混凝土的内部总孔隙变小,从而阻挡住二氧化碳的侵入,提高抗碳化能力。石粉质量分数的增多会减小机制砂自密实混凝土内机制砂颗粒与水泥浆体间的黏结作用,削弱其骨架作用,降低其抗冻耐久性能及力学性能,但会提高其抗碳化性能及抗氯离子渗透性能。

Taking machine-made sand and natural sand as fine aggregate, self-compacting concrete was prepared,through changing machine-made sand stone powder content and self-compacting concrete water-cement ratio, the test was carried out. The results showed thatthe liquidity of machine-made sand self-compacting concrete was than poorer than that of natural sand self-compacting concrete, but the compressive strength of machine-made sand self-compacting concrete was higher than that of natural sand self-compacting concrete. The stone powder content of self-compacting concrete had effect on the durability and mechanical properties of self-compacting concrete production, increasing stone powder content made the internal total pore in self-compacting concrete decrease, to block the invasion of the carbon dioxide to improve the carbonation resistance. The increase of stone powder content reduced the bond between machine-made sand particles and cement slurry in machine-made sand self-compacting concrete, weakened its skeleton function, decreased its frost resistance and mechanical properties, but improved its carbonization resistance and chloride ion penetration resistance.