复配外加剂体系对高性能混凝土收缩性能的影响

Compound Admixture System Effect on High Performance Concrete Shrinkage Performance

本文通过复配外加剂体系中不同外加剂(膨胀剂-减水剂-引气剂)、不同掺量对高性能混凝土(HPC)基本性能及收缩性能的对比试验,分析了不同掺量对HPC强度、弹性模量、收缩性能的影响程度。总结了对于有补偿收缩要求的HPC,综合对比了掺加不同外加剂时对其性能的影响,给出了各外加剂的最优建议掺量。根据试验所得最优掺量,为了阐明其内在机理,应用扫描电镜二次电子成像观测及能谱成分分析,阐明了复配外加剂的相容性及作用互补机理。研究不仅阐明了有补偿收缩要求的混凝土对外加剂的掺量要求,而且对有效控制混凝土开裂提供了理论配合比。由于配制HPC地材区域的差异性、外加剂批次和性能的差异性、相互之间相容性和匹配性的问题,本研究为类似研究提供参考和借鉴。

This article through the expansion agent, water reducing agent, air-entraining agent the different admixtures, different proportion of high performance concrete （HPC） basic properties and shrinkage performance comparative experiments, analyzed the different proportion of the influence degree of the HPC, summarized the shrinkage compensating for the requirements of the HPC, including strength, elastic modulus and shrinkage performance, comprehensive comparison of the admixture its influence on the performance of the contract is presented, and suggestions of the admixture the optimal dosage. By the means of SEM and EDS for illuminates inner mechanism. Study not only clarify the compensation shrinkage of concrete are required for the mixed quantity of admixture requirements, but also for effective control of the concrete cracking provides the theoretical mix. Due to the preparation of HPC is differences regional, admixtures batches and performance are difference, compatibility and matching problem between each other, this study for further scientific research and practical application to provide reference.