废弃混凝土对C_3S形成动力学的影响

Effect of Demolished Concrete on Formation Kinetics of C_3S

废弃混凝土中石灰石的含量比较稳定,适合取代天然石灰石作为钙质原料配制水泥生料,并含有少量的SiO2,可以起部分硅质原料的作用。硬化的水泥浆体在高温下脱水形成氧化钙、氧化铝和氧化铁等氧化物,都是制造水泥所必须的氧化物。实验室利用20%和40%的废弃混凝土代替部分石灰石制备水泥熟料。研究了废弃混凝土对硅酸盐水泥熟料形成动力学的影响。用快速滴定法测定了不同熟料中f-CaO含量,根据文章提出CaO反应生成C3S的转化率,并用Amhenius公式计算了熟料中C3S形成反应的表观活化能。研究表明:废弃混凝土能改善生料的易烧性,并能降低熟料的烧成温度。

Demolished concrete in which the majority is limestone,is suitable to be used as a replacement of natural limestone to produce cement raw meal,and the minority of SiO2 in the demolished concrete is a kind of siliceous raw material.Calcium oxide,alumina and ferric oxide are formed when solidified cement slurry is dehydrating at high temperature,which are necessary raw material for cement production.20% and 40% of natural limestone were replaced by demolished concrete to produce cement clinker in the laboratory,and influences of demolished concrete on the formation kinetics of portland cement clinker were studied.f-CaO content was determined using fast titration method,the conversion of CaO was calculated,and apparent activation energy of C3S in clinkers was calculated by Amhenius formula.Results illustrated that the demolished concrete can decrease the activation energy of C3S in clinkers,improve burning ability of raw meal and a lower sintering temperature of clinkers can be obtained.