陶粒加气混凝土收缩率试验研究

Experimental Study on Shrinkage Rate of Ceramsite Aerated Concrete

研究了自然养护、恒温恒湿养护(温度20℃、湿度70%)、3 d恒温恒湿养护后再自然养护对陶粒加气混凝土收缩率的影响。结果表明:3种养护方式下,试件均是前期膨胀后期收缩,且随着时间的增加,收缩率先快速增大后趋于稳定;恒温恒湿养护试件的前期膨胀率最大,后期收缩率与3 d恒温恒湿养护后再自然养护试件的收缩率相近;自然养护试件的前期膨胀率最小,后期收缩率最大。建议采用先恒温恒湿养护3 d再自然养护24 d的方式养护陶粒加气混凝土,此时,将陶粒加气混凝土应用于墙体砌筑工程时,不仅能加快材料堆放场地的周转,而且能有效减轻墙体收缩开裂。

The effects of natural curing,constant temperature and humidity curing(temperature at 20℃,humidity at 70%),and natural curing after 3 days of constant temperature and humidity curing on the shrinkage rate of ceramsite aerated concrete were studied.The results show that under the three curing methods,the specimens are expanded in the early stage and contracted in the later stage,and with the increase of time,the shrinkage rate first increases rapidly and then tends to be stable.The early expansion rate of specimens cured at constant temperature and humidity is the largest,and the later shrinkage rate is similar to that of the specimens cured naturally after 3 days of constant temperature and humidity curing.The early expansion rate of natural curing specimens is the smallest,and the later shrinkage rate is the largest.It is suggested that the ceramsite aerated concrete can be cured for 3 days at constant temperature and humidity,and then cured naturally for 24 days.At this time,when the ceramsite aerated concrete is applied to the wall masonry project,it can not only speed up the turnover of the material stacking site,but also effectively reduce the wall shrinkage and cracking.