基于正交试验的自密实混凝土塑性开裂研究  

Research on Plastic Shrinkage Cracking of Self-compacting Concrete Based on Orthogonal Experiment

作　　者：邱存元 于峰 QIU Cun-yuan;YU Feng(Shimen Reservoir Administrative Bureau,Hanzhong 723000,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]石门水库管理局,陕西汉中723000 [2]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《水电能源科学》2021年第5期155-160,共6页Water Resources and Power

摘　　要：针对汉中市石门水库在泄洪排沙洞改造、大坝加高等大体积混凝土浇筑初期出现的不同程度的塑性开裂问题,借助试验研究优化混凝土配合比,利用正交试验方法探索了自密实混凝土的塑性开裂面积与28d抗压强度的影响因素与影响规律。结果表明,粉煤灰掺量、减水剂掺量、水胶比对塑性开裂的影响十分明显,粉煤灰与减水剂存在显著交互作用,效应顺序排序为粉煤灰掺量>减水剂掺量>水胶比>交互作用,粉煤灰掺量、减水剂掺量、水胶比均取1水平时,对塑性开裂的影响权重值最大;粉煤灰掺量、水胶比、矿渣掺量对28d抗压强度的影响也十分明显,粉煤灰与矿渣存在显著交互作用,效应顺序排序为粉煤灰掺量>水胶比>矿渣掺量>交互作用,粉煤灰掺量、水胶比取1水平时、矿渣掺量取3水平时,对抗压强度的影响权重值最大。研究成果为石门水库除险加固工程大体积混凝土配合比设计提供了参考。In view of the different degrees of plastic cracking in the early stage of mass concrete pouring in the Shimen Reservoir of Hanzhong City,such as the reconstruction of the flood discharge tunnel and the height of the dam,the concrete mix ratio was optimized by experimental research.The orthogonal test method was used to explore the influencing factors and rules of the plastic cracking area and 28 d compressive strength of self-compacting concrete.The results show that the amount of fly ash,the amount of water-reducing agent,and the water-binder ratio have significant impacts on plastic cracking.There is an obviously interaction between fly ash and the water-reducing agent.The order of effects is sorted as:fly ash content>water-reducing agent content> water-binder ratio> interaction.When fly ash content,water-reducing agent content and water-binder ratio are all set to 1,the weight value of the influence on plastic cracking is the largest.The influence of fly ash content,water-binder ratio,and slag content on the 28-day compressive strength is also very obvious.There is a significant interaction between fly ash and slag.The order of effect is sorted as:fly ash content> water-binder ratio> slag content> interaction.When the amount of fly ash and water-binder ratio are set to level1,and the amount of slag is set to level 3,the weight value of the impact on compressive strength is the largest.The research results provide a reference for the design of the mass concrete mix ratio of the Shimen Reservoir’s reinforcement project.

关 键 词：正交试验 自密实混凝土 塑性开裂 抗压强度 层次分析 

分 类 号：TV544[水利工程—水利水电工程]