冻融循环下硅灰再生混凝土的力学性能试验研究  

Experimental research on mechanical properties of silica fume recycled concrete after freeze-thaw cycles

作　　者：张鑫鑫 黄靓[1] 刘文琦 赵鹏鹏 吕召宁 ZHANG Xinxin;HUANG Liang;LIU Wenqi;ZHAO Pengpeng;LÜZhaoning(College of Civil Engineering,Hunan University,Changsha 410082,China;Chinese Railway Construction Investment Group Co.,Ltd.,Beijing 102629,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]中建铁路投资建设集团有限公司,北京102629

出　　处：《混凝土》2024年第6期138-142,共5页Concrete

基　　金：国家重点研发计划(2019YFC1904700);中建集团重点科技创新课题“CZ铁路高原环境绿色与数字建造关键技术研究”(CSCEC-2021-S-2)。

摘　　要：为保障高原地区铁路工程产生的废弃混凝土资源化利用的安全性,采用快冻法,研究冻融循环后RAC力学性能。通过改变再生粗骨料种类、取代率以及硅灰掺量,研究RAC的抗冻性能以及冻融循环后的力学性能。通过冻融循环后RAC质量变化、动弹性模量变化、抗压强度变化以及劈裂抗拉强度变化,得出再生粗骨料的种类、取代率以及硅灰掺量的影响规律。试验表明:采用高强再生粗骨料能够提升RAC抗冻性能;再生粗骨料替代率为50%时,抗冻性能最好;硅灰会改善RAC抗冻性能。In order to ensure the safety of resource utilization of waste concrete produced by railway engineering in plateau area,the mechanical properties of RAC after freeze-thaw cycles were studied by rapid freezing method.By changing the type of recycled coarse aggregate,replacement rate and silica fume content,the frost resistance of RAC and the mechanical properties after freeze-thaw cycles were studied.Through the change of RAC quality,dynamic elastic modulus,compressive strength and splitting tensile strength after freeze-thaw cycle,the influence of recycled coarse aggregate type,replacement rate and silica fume content was obtained.The results show that high strength recycled coarse aggregate can improve the frost resistance of RAC.When the replacement rate of recycled coarse aggregate is 50%,the frost resistance is the best.Silica fume can improve the frost resistance of RAC.

关 键 词：再生混凝土 冻融循环试验 力学性能 硅灰 再生粗骨料 

分 类 号：TU528.01[建筑科学—建筑技术科学]