40
施工技术
CONSTRUCTION TECHNOLOGY
2012年11月下第41卷第377期
超磨细锂渣复合掺和料自密实高强混凝土
抗碳化性能研究
祝战奎，陈剑雄2
（1.北京新奥混凝土集团有限公司，北京100071；2.重庆大学材料科学与工程学院，重庆400045）
【摘要】研究了掺入超磨细锂渣及其与矿查、硅灰、石粉复合掺和料的自密实高强高性能混凝土的工作性、力学性，能与抗碳化性能。研究表明，该混土的工作性能优良，28d抗压强度达70.5~86.5MPa，90d达92~114MPa，后期强度发展强劲。通过对复合掺和料种类、比例与配合比的优化，探讨其对自密实高强混凝土的抗碳化性能的影响。当复合掺和料达45%时，其抗碳化寿命也可达百年以上的护筋要求，解决了大掺量掺和料的自密实混土碳化大、对钢筋保护不力的严重性间题。
【关键词】混凝土；复合掺和料；锂渣；自密实高强混凝土；抗碳化性能
【中图分类号】TU528.31
【文献标识码】A
【文章编号】1002-8498（2012)22-0040-03
Studyof CarbonationResistance of Self-compactingHigh-strength ConcretewithCompositeAdmixtureof Ultra-fineLithiumSlag
ZhuZhankui'，Chen Jianxiong”
(1. Bejing Xin'ao Concrete Group Co. , Lad. , Beijing 100071, China;
2. College of Materials Science and Engineering,Chongqing Unieersity, Chongqing400045,China)
Abstract:The working performance, mechanical properties and carbonation resistance of self-compacted concrete made from ultra-fine lithium slag with composite admixture including slag, silicon slag, fly-ash, lime stone was researched. Study indicated that the concrete has good performance. Its compressive strength can reach 70.5 ~ 86. 5MPa in 28 days, 92 ~ 114MPa in 90 days, and can develop very high long-term strength. Optimization studies were performed on the carbonation resistance of self-compacting concrete in terms of the types of composite admixture, their ratios and mixing proportions. When up to 45% of the cement was replaced by composite admixture, the carbonation resistance of the concrete can reach over 100 years, which means the reinforcements can be protected by 100 years. The study solved the critical problem that the self-compacting concrete with large quantity of admixture has low carbonation resistance and cannot provide sufficient protection to the reinforcements.
Key words: concrete; composite admixture; lithium slag; self-compacting high-strength concrete; carbonation resistance
高强度自密实混凝土的特点是胶结材及细组
分用量大，且必须使用外加剂降低水胶比并协调高流动性与黏聚性，使混凝土混合料保持成型时组分均勾、不离析、不泌水，容易充满模型。掺人超磨细工业废渣，可减少单位水泥用量，在促进环境改善的同时，能开发出性能稳定，后期强度发展良好的自密实高强混凝土"]，但高掺和料的混凝土往往碳化大、文献[1-2]表明加速碳化试验7d碳化深度最大达17.3mm，28d达28.2mm，这对于碳化寿命周期[收稿日期】2012-05-17
[作者简介】祝战奎，工程师，E-mail;zhuzhankui.student@ sina.eom 万方数据
为50"年内的混凝土结构还可用增加保护层厚度来解决，但严重碳化会产生碳化收缩裂缝，钢筋表面钝化膜破坏致使钢筋锈蚀严重，对耐久性造成严重影响。本文通过掺入超磨细锂及其与矿渣、硅灰、石粉复合，制备出抗碳化性能优异的自密实高强高性能混凝土，并对其抗碳化性能做重点研究，解决了大掺量掺和料的自密实混凝土碳化大，对钢
筋保护不力的严重间题。 1原材料及试验方法 1.1原材料
原材料：①水泥52.5R普通硅酸盐水泥；②锂