摘要
以冷黏成球法制备的碳酸化钢渣球形骨料为研究对象,分析了密实时间对钢渣球形骨料性质及碳酸化反应程度的影响.测试了不同密实时间下球形骨料碳酸化前后的表观密度、吸水率及孔隙率的变化规律,通过XRD、TG-DTG、MIP等手段分析不同密实时间下球形骨料物相变化、碳酸化程度、孔结构的变化,结果表明:采用冷黏成球工艺制备钢渣球形骨料时,密实时间对钢渣球形骨料的表观密度影响很小,但球形骨料的吸水率随密实时间的增加下降明显.当密实时间从5 min增加到30 min时,碳酸化前后球形骨料的吸水率分别下降了29.5%和26.0%.钢渣球形骨料的强度主要来源于碳酸化反应,且球形骨料的碳酸化反应程度和强度随密实时间的增加而下降.碳酸化前吸水率为14.86%的球形骨料碳酸化后强度最高,为6.1 MPa,达到同等粒径天然碎石强度的41%.碳酸化的过程是由外向内进行的,球壳的碳酸化反应程度高于球心,且碳酸化前球壳越致密,球心的碳酸化反应程度越低.
Taking the spherical aggregate of carbonated steel slag prepared by cold bonding pelletization as research object, the effect of compacting time on the properties and carbonation degree of spherical aggregates made by carbonated steel slag was investigated. Changes of apparent density, water absorption ratio and porosity of spheres before and after carbonation in different compacting time were tested. Variation of phase, carbonation degree and pore structure in different compacting time were respectively characterized by XRD, TG-DTG and MIP. Results show that the apparent density of spherical steel slag aggregates prepared by cold bonding pelletization is rarely affected by the compacting time, but the water absorption decreases obviously with increasing of the compacting time. When the compacting time increases from 5 min to 30 min, the water absorption of spherical aggregate decreases by 29.5% and 26.0% before and after carbonation, respectively. Strength of spherical steel slag aggregate mainly comes from carbonation reaction, and the degree of carbonation reaction and strength of spherical aggregate decrease with compacting time increasing. The spherical aggregate with 14.86% water absorption before carbonation has the highest strength after carbonation, which is 6.1 MPa, reaching 41% of strength of natural gravel with the same particle size. Process of carbonation is carried out from outside to inside. Degree of carbonation reaction of spherical shell is higher than that of spherical center. Denser spherical shell before carbonation leads to lower degree of carbonation reaction of spherical center.
作者
常钧
于春阳
CHANG Jun;YU Chunyang(School of Civil Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2019年第3期257-263,共7页
Journal of Dalian University of Technology
基金
国家自然科学基金资助项目(51172096)
关键词
冷黏成球法
钢渣
碳酸化
人造骨料
cold bonding pelletization
steel slag
carbonation
artificial aggregate
