改性超疏水混凝土工程性能及微观机理研究

Study on Engineering Performance and Microstructure Mechanism of Modified Superhydrophobic Concrete

该研究从降低混凝土亲水性角度解决其耐久性问题。研究制备了DC-30改性超疏水混凝土,通过开展室内试验分析其吸水性,以及润湿性、抗压强度、抗折强度随加湿养护时间的发展规律。研究发现:(1)DC-30超疏水混凝土表现出优异的超疏水性,其吸水率仅为普通混凝土的11%~40%。(2)DC-30的加入对混凝土的强度有一定的不利影响,不加湿养护的超疏水混凝土的抗压强度折减了40.6%,抗折强度折减了32.3%,表现更明显的脆性破坏,原因为DC-30的超疏水性而加快了混凝土的内部水分流失,造成水化不足而导致强度削减。(3)加湿养护能显著提升超疏水混凝土的强度,加湿养护28天后,抗压强度和抗折强度分别折减了7.7%和8.1%。

In this study,the durability problem of concrete was solved from the perspective of reducing hydrophilicity.Laboratory tests were carried out on DC-30 modified superhydrophobic concrete to analyze its water absorption,and the development law of wettability and strength with humidification curing time.The results show that:(1)DC-30 superhydrophobic concrete shows excellent superhydrophobicity,and its water absorption rate is only 11%~40%of ordinary concrete.(2)The addition of DC-30 has a certain adverse effect on the strength of concrete.The compressive strength and flexural strength of superhydrophobic concrete cured without humidification are reduced by 40.6%and 32.3%,showing more obvious brittle failure;The reason is that the super hydrophobicity of DC-30 accelerates the internal water loss of concrete,resulting in insu fficient hydration and strength reduction.(3)Humidification curing can significantly improve the strength of superhydrophobic concrete.After 28 days of humidification curing,the compressive strength and flexural strength are reduced by 7.7%and 8.1%respectively.