喷射混凝土水化度的试验与理论模型研究  

Experimental and Theoretical Study on Cement Hydration Degree of Shotcrete

作　　者：王家赫 WANG Jiahe(Railway Engineering Research Institution,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司,铁道建筑研究所,北京100081

出　　处：《材料导报》2022年第23期80-84,共5页Materials Reports

基　　金：国家自然科学基金(51908550)。

摘　　要：本工作以喷射混凝土为研究对象,通过绝热温升试验测试得到使用不同种类和不同掺量液体速凝剂时喷射混凝土绝热状态下芯部温度升高值随养护龄期的变化关系。另外,引入等效龄期概念,计算得到喷射混凝土水化度随等效龄期的变化关系,消除了绝热温升试验中环境温度的影响。进一步地,提出改进的喷射混凝土水化度计算模型,通过引入等效龄期影响因子考虑了速凝剂对喷射混凝土早龄期水化加速作用的影响。试验和理论研究结果表明:使用有碱速凝剂和无碱速凝剂均可显著加速喷射混凝土早龄期水化进程,但无碱速凝剂对后期水化影响较小,而有碱速凝剂对后期水化影响较大;引入等效龄期后,喷射混凝土水化度发展历程呈现两阶段模式,即快速发展期和平稳期。所提出的适用于喷射混凝土的水化度计算模型充分考虑了速凝剂的使用对喷射混凝土早龄期水化的加速作用,尤其对喷射混凝土早龄期水化度的模拟计算结果更为准确。In this work,shotcrete was taken as the research object,and the relationship between the core temperature rise and the curing age of shotcrete under the adiabatic state was obtained by the adiabatic temperature rise test with different kinds and different amounts of liquid accelerators.By introducing the concept of equivalent age,the relationship between the hydration degree of shotcrete and the equivalent age was calculated,and the influence of environment temperature in adiabatic temperature rise test was eliminated.An improved calculation model of hydration degree of shotcrete was proposed.The effect of accelerator on the early age hydration of shotcrete was considered by introducing the equivalent age acceleration factor.The experimental and theoretical research results show that the hydration process of shotcrete at early age can be significantly improved,whether alkaline or alkali-free accelerator is used.However,the alkali-free accelerator make little difference in the later hydration,while the alkaline accelerator does obviously.After the introduction of equivalent age,the development process of the hydration degree of shotcrete presents a two-stage model,namely the rapid development period and the stable period.The proposed model for calculating the hydration degree of shotcrete fully considers the accelerating effect of accelerator on the early age hydration of shotcrete,especially the more accurate simulation calculation of the early age hydration degree of shotcrete.

关 键 词：喷射混凝土 水化度 模型计算 绝热温升 速凝剂 

分 类 号：TU528[建筑科学—建筑技术科学]