矿渣对界面过渡区微力学性质的影响

Effects of Blast Furnace Slag on Micro-Mechanical Properties of Interface Transition Zone

采用纳米压痕技术测试了矿渣取代水泥的质量分数分别为0%,30%,50%,80%时的混凝土中实际界面过渡区及邻近区域的纳米压痕硬度和弹性模量分布以了解矿渣对混凝土界面过渡区微力学性质的影响。试验结果表明:矿渣掺量为30%时,距集料表面25μm以内区域的弹性模量、纳米压痕硬度明显低于距集料表面25μm以外的区域,而当矿渣掺量达到50%时,弹性模量和纳米压痕硬度沿界面的变化不显著;随矿渣取代水泥质量分数的增加,基体与界面过渡区之间压痕硬度、弹性模量的差值降低,从而使界面过渡区得到强化。

Elastic modulus and the hardness of the interface transition zone and neighboring zone of con-crete with 0, 30%, 50% and 80% cement replaced by blast furnace slag are tested by nano-indentation. Results show that the minimum values occur at 5-25μm from the aggregate surface for both elastic modulus and the hardness when blast furnace slag substitution is lower than 30% ; both elastic modulus and the hardness are unchange evidently with the distance from the aggregate surface when the blast furnace slag substitution exceeds 50%; the difference of the hardness or the elastic modulus between inter-face transition zone （a thickness of 25μm） and the bulk matrix decreases with the increase of blast furnace slag, thus strengthening the benefit effects of slag interface transition zone.