掺氢氧化钙对超高强混凝土力学性能影响的机理  

Mechanism for the Influence of Added Hydrated Lime on Mechanical Properties of Ultra-high Strength Concrete

作　　者：朋改非[1] 张贵[1] 左雪宇 丁宏 陈喜旺 王海迪 刘新建 PENG Gaifei;ZHANG Gui;ZUO Xueyu;DING Hong;CHEN Xiwang;WANG Haidi;LIU Xinjian(Faculty of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Construction Third Bureau Group Beijing Limited Liability Company,Beijing 100162,China;Beijing Construction Engineering Group,Advanced Construction Materials Limited Liability Company,Beijing 100015,China;Beijing Construction Engineering Group,Hengjun Engineering Detection Limited Liability Company,Beijing 102615,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中建三局集团北京有限公司,北京100162 [3]北京建工新型建材有限责任公司,北京100015 [4]北京建工恒均工程检测有限公司,北京102615

出　　处：《材料导报》2024年第3期110-115,共6页Materials Reports

基　　金：国家自然科学基金(51878032);北京市自然科学基金(8212013,8172036)。

摘　　要：鉴于含矿物掺合料较多的超高性能混凝土(Ultra-high performance concrete,UHPC)中火山灰反应所需氢氧化钙含量不足的状况,在配制超高强混凝土(UHPC基体)时掺加氢氧化钙,研究其对超高强混凝土力学性能的影响机理。结果表明,超高强混凝土力学性能的改善源于掺入的氢氧化钙与矿物掺合料中的SiO_(2)发生火山灰反应生成C-S-H及C-A-S-H凝胶,且在组合养护(90℃热水养护2 d+250℃干热养护3 d)下,部分C-(A)-S-H凝胶向托勃莫来石与硬硅钙石晶体转变,改善了超高强混凝土的微观结构。Based on the drawback of insufficient calcium hydroxide content required for pozzolanic reaction in ultra-high performance concrete(UHPC)incorporating high volume mineral admixtures,hydrated lime was intentionally added into the ultra-high strength concrete(matrix of UHPC)to investigate its influence on the mechanical properties of ultra-high strength concrete.The mechanism for the improvement in mechanical properties of ultra-high strength concrete should be pozzolanic reaction between hydrated lime and mineral admixtures,which formed C-S-H and C-A-S-H gels.Partial C-(A)-S-H gels were transformed into tobermorite and xonotlite crystals under combined curing(90℃hot water curing for 2 d and 250℃dry air heating for 3 d),which improved both the microstructure and mechanical properties of ultra-high strength concrete.

关 键 词：超高强混凝土 氢氧化钙 力学性能 机理 

分 类 号：TU528[建筑科学—建筑技术科学]