低水灰比高性能混凝土的耐久性研究

Research on the durability of high performance concrete with low water-binder ratio

高性能混凝土的特点是低水胶比、高胶凝材料用量。本文较系统地研究了低水灰比混凝土的水化程度,未水化胶凝材料后期继续水化对混凝土强度的影响,并采用超声波无损检测技术研究了后期水化对混凝土结构的损伤情况。研究表明低水灰比混凝土中存在大量未水化水泥,其后期继续水化将导致混凝土损伤,抗压强度显著降低,耐久性变差。且水灰比越低,未水化胶凝材料后期继续水化产生的危害越大。

Low water-binder ratio and abundant binder are the characters of high performance concrete. Degree of hydration and harm of unhydrous cement on concrete are studied in this paper. The concrete structure is detected by the ultrasonic nondestructive detection instrument. It is shown that there is a lot of anhydrous cement in low water-binder ratio concrete. They result in concrete compressive strength and durability reduction when they continue hydration in later stage. Furthermore, the lower the water-binder ratio is, the severer the concrete deterioration is when anhydrous cement continues hydrating in later stage.