纳米SiO2对混凝土性能影响的研究进展

Progress of the Effect of Nano-SiO2 on Concrete Properties

摘要:

混凝土是土木工程中使用最为广泛的材料之一，当今普通混凝土已无法完全满足超限建筑业的需求，因此高性能纳米SiO₂改性混凝土应运而生。为更好地了解纳米SiO₂改性混凝土的各项性能，对其和易性、凝结时间、抗压强度和抗氯离子渗透性的研究进行了回顾和总结。相关研究表明：在混凝土中添加适量纳米SiO₂，可有效提高混凝土的抗压强度，且对早期抗压强度的影响大于后期的影响，但纳米SiO₂含量过高会使混凝土的抗压强度下降；适量的纳米SiO₂，还可以有效填充混凝土中的孔隙，改善其微观结构，提高混凝土的抗氯离子渗透性；然而，混凝土中掺入纳米SiO₂，会缩短其初凝时间和终凝时间，同时也会大幅影响混凝土的和易性，使之不利于长距离输送，增加施工难度。

Abstract:

The nano-SiO₂ modified concrete （NSC） was applied in the field of limit-beyond high-rise building. For better understand the properties of NSC， the workability， setting time， compressive strength and chloride penetration resistance of NSC were reviewed and summarized. The previous researches showed that the compressive strength with an appropriate amount of nano-SiO₂ could be effectively improved， and the influence on the early compressive strength is greater than the long term one . nano-SiO₂ could also be filled in the concrete voids， improving microstructure and the chloride penetration resistance of concrete. However， the setting time of concrete with nano-SiO₂ reduced leading to unfavourable workability of concrete， which was not conducive to long-distance transportation and construction.