纳米C-S-H/PCE对蒸养UHPC力学性能增强机理研究  

Enhancement Mechanism of Mechanical Properties of Steam-Cured UHPC by Nano-C-S-H/PCE

作　　者：伍勇华[1] 易昂 何娟 匡玉峰 原毅冰 WU Yonghua;YI Ang;HE Juan;KUANG Yufeng;YUAN Yibing(College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《硅酸盐通报》2024年第8期2797-2805,共9页Bulletin of the Chinese Ceramic Society

基　　金：陕西省自然科学基础研究计划项目(2021JM-353)。

摘　　要：目前超高性能混凝土(UHPC)制品的力学性能有待进一步提升,采用纳米C-S-H/PCE对UHPC进行增强在理论上是一种可行的技术途径。本文研究了蒸养条件下掺入以聚羧酸(PCE)为分散剂的纳米水化硅酸钙(C-S-H/PCE)对UHPC力学性能的影响,通过测试水化热、水化产物、微观形貌和孔结构等对其机理进行了分析。结果表明,掺入3.0%(质量分数)纳米C-S-H/PCE可以显著提高蒸养UHPC的抗压强度和抗折强度。掺入纳米C-S-H/PCE可以促进UHPC的早期水化,生成更多的水化硅酸钙(C-S-H)凝胶,使水化放热温峰增高,并缩短达到水化温峰的时间。掺入纳米C-S-H/PCE可有效改善蒸养UHPC的孔结构,在掺量为3.0%(质量分数)时总孔隙率最小,有害孔比例最低。该研究可为纳米C-S-H/PCE在蒸养UHPC中的应用提供参考。At present,the mechanical properties of ultra-high performance concrete(UHPC)products need to be further improved,and the use of nano-C-S-H/PCE to enhance UHPC is a feasible technical way in theory.The effect of nano-C-S-H/PCE on the mechanical properties of UHPC under steam-cured condition was studied.The influence mechanism was analyzed by measuring hydration heat,hydration products,microstructure and pore structure.The results show that the incorporation of 3.0%(mass fraction)nano-C-S-H/PCE significantly increases compressive and flexural strengths of steam-cured UHPC.The addition of nano-C-S-H/PCE can promote the hydration in early age of UHPC and form more C-S-H gel,and increase the exothermic temperature peak of hydration and shorten time to reach the hydration temperature peak.Also,the pore structure of steam-cured UHPC can be improved effectively by adding nano-C-S-H/PCE,and the total porosity and harmful pore proportion are the lowest at 3.0%(mass fraction)nano-C-S-H/PCE.This study can provide a theoretical reference for the application of nano-C-S-H/PCE in steam-cured UHPC.

关 键 词：纳米C-S-H/PCE 超高性能混凝土 孔结构 水化放热 蒸汽养护 

分 类 号：TU528[建筑科学—建筑技术科学]