HCSA膨胀剂掺量对高强自密实混凝土性能影响研究  

Investigation on influence of HCSA expansive agent dosage on performance of high-strength self-compacting concrete

作　　者：李彪[1] 徐礼华[1] 谷雨珊[1] 贾丽莉[2] LI Biao XU Lihua GU Yushan JIA Lili(School of Civil and Architectural Engineering, Wuhan University, Wuhan 430072, China China Construction Commercial Concrete Co. , Ltd. , Wuhan 430072, China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]中建商品混凝土有限公司,湖北武汉430072

出　　处：《武汉大学学报（工学版）》2017年第1期90-96,共7页Engineering Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:51278388)

摘　　要：设计制作5种HCSA膨胀剂掺量的高强自密实混凝土试块,通过混凝土工作性、抗压强度和自由膨胀率以及在钢管约束条件下混凝土自应力值测试,研究HCSA膨胀剂掺量对高强自密实混凝土性能的影响.结果表明:掺入膨胀剂对混凝土工作性影响较小;随膨胀剂掺量增加,混凝土自由膨胀率逐渐增大,而28d抗压强度则快速下降;膨胀剂水化主要集中在混凝土硬化早龄期,自由膨胀变形于12~15d范围内达到稳定.在钢管约束条件下,混凝土膨胀稳定滞后,且当膨胀剂掺量为8%~12%,混凝土膨胀稳定时自应力值达3.2~3.7 MPa.最后,基于试验与理论分析结果,建立钢管约束条件下混凝土限制膨胀模型及自应力值计算公式,计算结果与试验结果吻合较好,可供工程设计参考.This paper investigates the influence of HCSA expansive agent dosage on the performance of high-strength self-compacting concrete. The tests were performed on high-strength self-compacting con- crete block with five mass fractions of expansive agent considered. The workability, compressive strengths, free expansion ratios as well as the self-stress values under steel tubular constraint condition were measured. The test results indicate that the addition of the expansive agent to the concrete had slight influence on the workability. The free expansion ratio gradually increased, but the concrete compressive strength of the age of 28 d decreased significantly with the increase in the dosage of expansive agent. Ex- pansive agent hydration mainly concentrated in the early age, and the free expansion strain reached steady- state with the scope of 12-15 d. It is also noted that the steady-state value of self-stress in concrete can reach to 3.2-3.7 MPa when the expansive agent content is 8 %-12 % mass fraction; but it may be hysteretic to reach the steady-state. Furthermore, based on the experiments and theoretical analysis results, a con crete confined expansion model is established; and predictive equations for the self-stress are developed un- der circular steel tubular constraint and that the calculation results are in good agreement with test results, which can serve as a reference for practical engineering design.

关 键 词：高强自密实混凝土 HCSA膨胀剂 钢管约束条件 自应力值 膨胀模型 

分 类 号：TU528.55[建筑科学—建筑技术科学]