标养条件下掺固硫灰活性粉末混凝土的耐久性初探

Durability of reactive pow der concrete with circulating fluidized bed combustion fly ash

主要研究在标准养护条件下工业副产物固硫灰对活性粉末混凝土抗冻融循环、抗碳化以及抗硫酸盐侵蚀等性能。试验结果表明:掺有固硫灰所制备的RPC表现出良好的抗碳化性能,28 d碳化深度为0;冻融循环进行到350次时,RPC具有较好的抗冻性能;在浓度为5%的Na_2SO_4溶液中浸泡28 d时,RPC表现出较好的抗硫酸盐侵蚀性能。综上可得,利用固硫灰的膨胀优势,可以提高混凝土的密实性,改善混凝土的微观结构,从而提高混凝土的耐久性。

RPC with best circulating fluidized bed combustion fly ash after curing under standard condition for 28 d was used to test its durability,such as its resistance to freezing-thawing cycles,anti-carbonation and sulphate attack.The results of anti-carbonation test show RPC has good anti-carbonation performance,the carbonation depth remain zero when carbonation for 28 d.The mass loss of RPC keep zero after freezing-thawing cycles to 350 times,this results also show RPC has good freezing-thawing resistance.RPC also show better resistance to sulphate erosion when soaked in different concentrations of 5%Na2SO4 solution for a month.Moreover,CFBC fly ash is good to improve the micro-structure and durability of concrete by making full use of its expansibility.