摘要
首先用100%再生细骨料混凝土制备二次与三次循环再生细骨料,探讨了再生细骨料性能变化规律;然后采用ASTM C1202电通量法,研究了再生细骨料取代率为0、25%、75%、100%条件下,一次、二次和三次再生细骨料混凝土氯离子渗透性变化规律。结果表明:随着再生细骨料循环次数的增加,再生细骨料的表观密度、胶砂强度比下降,吸水率、需水量比、细度模数增大;再生细骨料混凝土强度和抗氯离子渗透性显著降低。随着再生细骨料取代率的增加,再生细骨料混凝土强度和抗氯离子渗透性降低幅度不大,但二次和三次再生细骨料混凝土降低幅度明显高于一次再生细骨料混凝土。建立了再生细骨料混凝土氯离子渗透系数与再生细骨料取代率之间的关系方程,一次再生细骨料混凝土氯离子渗透系数符合指数函数变化,而二次和三次则符合一次函数线性变化。
First,recycled fine aggregate concrete using 100% recycled fine aggregate was used to prepare second and third recycled fine aggregate,and the properties of all fine aggregate were analized.Then chloride ion permeability of recycled fine aggregate concrete was investigated through replacing 0,25%,75%,and 100% natural fine aggregate with first,second and third recycled fine aggregate.The results indicate that with the increasing number of repetitions,recycled fine aggregate has decreased apparent density and mortar strength,increased water absorption,water demand and fineness modulus,and strength and resistance to chloride ion permeability of recycled fine aggregate concrete decrease significantly.With the increase of the replacement rate of recycled fine aggregate,the strength and resistance to chloride ion permeability of recycled fine aggregate concrete did not significantly reduced,but second and third recycled fine aggregate concrete show bigger trend reduced than first recycled fine aggregate concrete.The relationship between chloride ion permeability and replace ratio of recycled fine aggregate was established,where exponential function was used for first recycled fine aggregate concrete,and linear change function for second and third recycled fine aggregate concrete.
出处
《混凝土》
CAS
北大核心
2016年第9期21-24,28,共5页
Concrete
基金
国家自然科学基金(51278073)
江苏省产学研合作前瞻性联合研究项目(BY2013024-17
BY2014037-30
BY2015027-23)
关键词
再生混凝土
循环再生细骨料
氯离子
渗透性
recycled concrete
repeated recycled fine aggregate
chloride ion
penetrability
