大流态混凝土配合比与新拌和硬化混凝土性能关系剖析  

Investigation on the relationship between mix proportion and properties of fresh and hardened fluidized concrete

作　　者：韩建国[1] 阎培渝[1] 师海霞[2] 李俊亮 HAN Jianguo;YAN Peiyu;SHI Haixia;LI Junliang(Department of Civil Engineering,Tsinghua University,Beijing 100084,China;China Concrete and Cement-based Products Association,Beijing 100831,China;Beijing Building Materials Testing Academy Co.,Ltd.,Beijing 100041,China)

机构地区：[1]清华大学土木工程系,北京100084 [2]中国混凝土与水泥制品协会,北京100831 [3]北京建筑材料检验研究院有限公司,北京100041

出　　处：《混凝土》2021年第6期1-8,共8页Concrete

基　　金：国家自然科学基金(51678343,51878381)。

摘　　要：对39个强度等级为C35的大流态混凝土,通过协方差分析和图像分析,探讨了配合比参数对混凝土工作性、强度、抗渗透能力和抗离析能力的影响;通过非线性拟合,探讨了胶凝材料体系中的矿物掺合料的活性系数高低及其对强度发展历程的影响.研究结果表明:混凝土的工作性、强度和抗渗透能力与配合比参数之间为多元约束关系,影响工作性的显著因素是减水剂掺量、水胶比、砂率和浆骨比,影响强度的显著因素是粗骨料级配、水胶比、胶凝材料用量和减水剂用量,影响抗渗透能力的显著因素是胶凝材料用量、水胶比、粗骨料级配和减水剂用量.图像分析结果可量化表征混凝土的离析程度,39个大流态混凝土均具有良好的抗静态离析能力.矿物掺合料的水化活性随龄期的发展而变化,矿渣粉在28 d龄期时展示出水化活性,粉煤灰在90 d龄期时展示出水化活性,石灰石粉在90 d龄期时依然未展示出水化活性.混凝土的强度与抗渗性之间展示出指数关系,且两者之间的关系的离散性反映了胶凝材料用量、水胶比、矿物掺合料水化活性和粗骨料级配的综合影响。The influence of mix proportion parameters on the workability,strength,anti-permeability and anti-segregation ability of 39 C35 highly fluidized concretes was investigated using covariance analysis and image analysis.Through nonlinear fitting,the activity coefficient of mineral admixtures was determined and their influence on the strength development of concrete was discussed.Research results show that the workability,strength and anti-permeability of highly fluidized concrete are in a multi-constraint relationship with its mix proportion parameters.The significant factors affecting the workability of highly fluidized concrete are dosage of water reducing admixture(WRA),water-binder ratio,sand ratio and paste to aggregate ratio.The significant factors affecting the strength of highly fluidized concrete are coarse aggregate gradation,water-binder ratio,binder content and WRA dosage.The significant factors affecting the anti-permeability of highly fluidized concrete are binder content,water-binder ratio,coarse aggregate gradation and WRA dosage.The image analysis result can quantify the segregating degree of concrete.All the highly fluidized concretes explored have good static anti-segregation ability.The hydration activity of mineral admixtures changes with the development of curing age.Ground granulated blast-furnace slag(GGBS)reveals hydration activity at 28 days of age,fly ash reveals hydration activity at 90 days of age,and limestone powder did not show any hydration activity up to 90 days of age.There is an exponential relationship between concrete strength and its anti-permeability,and the discreteness of the relationship comprehensively reflects the influence of binder content,water-binder ratio,hydration activity of mineral admixture and coarse aggregate gradation on concrete strength and anti-permeability.

关 键 词：大流态混凝土 配合比 工作性 强度 抗渗透能力 抗离析能力 

分 类 号：TU528.062[建筑科学—建筑技术科学]