矿物掺合料和养护方式对轻骨料混凝土吸水性的影响

Effect of mineral admixtures and curing conditions on the water absorption of lightweight aggregate concrete

混凝土吸水性与耐久性之间有着密切的关系,混凝土要获得高耐久性的其中一个关键就是防止有害离子通过水溶液进入混凝土。因此研究水进入混凝土表面的速率成为研究混凝土耐久性的一种重要方法。利用吸水试验测得轻骨料混凝土(水胶比0.44)在不同矿物掺合料和养护方式下的吸水率变化,然后通过数据分析得出其吸水率变化曲线。比较这些曲线之间的变化,可发现:①轻骨料混凝土在蒸汽养护前期其吸水率小于标准养护条件下的吸水率,但蒸汽养护后期两者的变化基本相同。②蒸汽养护条件下,掺入粉煤灰,不利于轻骨料混凝土吸水率的降低。③蒸汽养护条件下,硅粉的掺入降低了混凝土的表面吸水率,对轻骨料混凝土的耐久性是有利的。

There is a close relationship between water absorption and durability of concrete.One of the key factors to obtain high dura-bility concrete is to prevent harmful ions through aqueous solution into the concrete.So studying the rate of water into concrete surface be- came an important method to investigate the durability of concrete.Based on the water absorption test, the variation of water absorption of lightweight aggregate concrete（water-binder ratio is 0.44 ） which mixed different mineral admixture and were under different curing condi-tions were studied.Then through data analyzing,the water absorption curves were obtained.And comparing these curves,we find that ①in early curing age,the water absorption of lightweight aggregate concrete under steam curing is smaller than the one under standard curing,but as period of curing increases,both the changes of water absorption of lightweight aggregate concrete under two cuing conditions are nearly the same; ②under the two curing conditions,mixing fly ash is bad for lightweight aggregate concrete to reduce its water absorption, ③mix-ing silica fume can reduce water absorption of concrete surface so that it can help to improve the durability of lightweight aggregate concrete.