LiNO_3对活性集料碱-硅酸反应的抑制效果

Effects of lithium nitrate on controlling ASR expansion of reactive aggregates

试验采用快速砂浆棒法和小混凝土柱法研究LiNO3对沸石化珍珠岩、防城港砂岩、锦屏砂岩和两河口砂岩四种集料ASR膨胀的抑制效果。研究表明,对于沸石化珍珠岩,掺加锂盐对试件ASR膨胀有较好的抑制效果,但是当锂盐掺量不足时在后期膨胀率甚至超过了未掺锂盐的试件。对于防城港砂岩,两种试验方法都表明,[Li]/[Na+K]摩尔比越大,试件的膨胀率越小。足量的LiNO3对ASR膨胀的抑制效果越好。对于锦屏砂岩,[Li]/[Na+K]摩尔比越大,砂浆试件膨胀率越小。对于两河口砂岩,两组试验都表明,掺加LiNO3的试件的膨胀率在后期都超过了未掺锂盐的试件;砂浆试件中[Li]/[Na+K]=2.22时,在短龄期内才有一定的抑制效果。

Tests were carried out to determine the efficacy of LiNO3 on controlling expansion of mortar bars and microbars prepared with four alkali-silica reactive aggregates.Results showed that, for zeolitization perlite, specimens with LiNO3 showed good inhibition effect in both tests;but while the content of LiNO3 was insufficient, later expansion may even more than those of no lithium specimen.For Fangchenggang sandstone, the results of this two methods showed that greater inhibition was caused with increasing molar ratio of [Li]/ [Na＋K] and enough content of LiNO3 was better for ASR inhibition.For Jinping sandstone, the bigger of molar ratio of [Li]/[Na＋K], the greater inhibition of mortar bars.For Lianghekou sandstone, while the content of LiNO3 was insufficient in mortars and microbars,later ex- pansion may even more than those of no lithium specimens;it had certain inhibition effect when molar ratio of [Li]/[Na＋K] was 2.22 in mortars in short age.