摘要
为进一步理解不同温度下含多种胶凝组份的自密实混凝土的水化特性,采用等温量热和水化动力学模拟等方法,分别研究掺粉煤灰、矿粉、膨胀剂、纳米硅和黏度改性剂等矿物外加剂水泥复合胶凝体系在5,10,20和30℃下的水化放热速率和放热量,并基于Cahn动力学模型计算水化产物的成核速率和生长速率,讨论温度和矿物外加剂对相应水化动力学参数的影响。研究结果表明:矿物外加剂的掺入,降低了胶凝体系水化放热峰值,增大了水化产物的成核速率,促进了水化放热速率峰值提早出现,膨胀剂和纳米二氧化硅促进作用尤为明显;温度升高明显增大了体系水化产物的成核速率与生长速率,且对多元复合胶凝体系的影响更为显著。
In order to further understand the hydration characteristics of Self-Compacting Concrete containing various cementitious components at different temperatures. Isothermal calorimetry and hydration kinetics simulation were used to study the hydration heat evolution rate and cumulative hydration heat of cement composite cementitious system with mineral admixture such as fly ash, slag, expansion agent, nano SiO2 and viscosity modifier at 5, 10, 20 and 30 ℃. The nucleation rate and growth rate of the hydration products were calculated based on the Cahn’s kinetic model, and the effect of temperature and mineral admixture on the hydration kinetics parameters were discussed. The results show that the mineral admixtures can reduce the peak value of evolution rate of the cementitious system, increase the nucleation rate of hydration products, stimulate the appearance of the peak value of evolution rate, and the promotion effect of expansion agent and nano SiO2 are more obvious. The nucleation rate and growth rate of hydration products are significantly increased at high temperature, and it will be more obvious when it comes to the multiple composite cementitious system.
作者
党晗菲
龙广成
马聪
李袁媛
马昆林
谢友均
DANG Hanfei;LONG Guangcheng;MA Cong;LI Yuanyuan;MA Kunlin;XIE Youjun(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Laboratory of High-speed Railway Construction Technology,Changsha 410075,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2019年第4期907-914,共8页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51678568)
高铁联合基金资助项目(U1534207)
关键词
复合胶凝体系
温度
水化放热速率
水化动力学模型
动力学参数
composite cementitious system
temperature
hydration heat evolution rate
hydration kinetics model
kinetic parameters
