低收缩轻质超高韧性水泥基材料的组成设计与弯曲力学行为研究  

Research on composition design and flexural mechanical behavior of low-shrinkage lightweight ultra-high toughness cement-based materials

作　　者：赵明宇 李志强[1] 谯理格 王晴 王心童[1] 丁庆军 ZHAO Mingyu;LI Zhiqiang;QIAO Lige;WANG Qing;WANG Xintong;DING Qingjun(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China;China Construction ReadyMixed Concrete Co.,Ltd.,Wuhan 430074,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168 [2]中建商品混凝土有限公司,湖北武汉430074 [3]武汉理工大学硅酸盐建筑材料国家重点实验室,湖北武汉430070

出　　处：《混凝土》2023年第12期108-114,共7页Concrete

基　　金：国家自然科学基金(51908378,U21A20149);硅酸盐建筑材料国家重点实验室开放课题基金(SYSJJ2020-07);高性能土木工程材料国家重点实验室开放基金课题(2019CEM010);辽宁省博士科研启动基金计划项目(2021-BS-170);中建股份青年科技研发项目(CSCEC-2021-Q-61)。

摘　　要：针对钢-混凝土组合桥面结构对混凝土铺装材料体积稳定性、韧性与自重的要求,提出利用轻质陶砂与陶粒取代混凝土中的粗细集料、利用多锚点钢纤维部分取代PVA纤维的技术思路,分析了集料组成、矿物掺合料、膨胀剂、纤维种类及掺量对材料工作性能、力学性能、体积稳定性能的影响规律,开发出了适用于钢桥面铺装的低收缩轻质超高韧性水泥基材料,并通过与普通纤维混杂增韧C50混凝土对比,研究了材料在受弯破坏过程中的韧性特征以及弯曲疲劳性能。结果表明,制备的低收缩轻质超高韧性水泥基材料28 d抗压强度62.7 MPa,坍落度140 mm,干燥收缩率47×10^(-6),表观密度1840 kg/m^(3),弯曲韧性指数I20=24.01,与混杂纤维增韧C50混凝土相比,弯曲疲劳性能优异,在0.65、0.70、0.75、0.80、0.85应力水平下的疲劳寿命分别是其4.9倍、10.8倍、16.4倍、31.4倍、60.6倍。Aiming at the requirements of steel-concrete composite bridge deck structure for the volume stability,toughness and self-weight of concrete pavement materials,it proposes the technical idea of replacing the coarse and fine aggregates in concrete with lightweight pottery sand and ceramsite,and partially replacing PVA fibers with multi-anchor steel fibers,analyzes the influence of aggregate composition,mineral admixture,expansive agent,fiber type and dosage on material working properties,mechanical properties and volume stability performance,and develops a low-shrinkage lightweight ultra-high toughness cement-based material suitable for steel bridge deck paving.By comparing with the ordinary hybrid fibers toughened C50 concrete,the toughness characteristics and flexural fatigue performance of the material in the process of flexural failure were studied.The results show that the low-shrinkage lightweight ultra-high toughness cement-based material has a compressive strength of 62.7MPa,a slump of 140 mm,a drying shrinkage rate of 47×10^(-6),a bulk weight of 1840 kg/m^(3),and a flexural toughness index I20=24.01,which has excellent flexural fatigue performance compared with hybrid fibers toughened C50 concrete,and the fatigue life at the stress levels of 0.65,0.70,0.80 and 0.85 is 4.9 times,10.8 times,16.4 times,31.4 times and 60.6 times respectively.

关 键 词：轻质 高韧性 低收缩 弯曲力学性能 水泥基材料 

分 类 号：TU528.041[建筑科学—建筑技术科学]