基于HYMOSTRUC3D的水泥基材料微结构变化规律研究

Research on Cement Hydration Microstructure Evolution Process Based on HYMOSTRUC3D Model

现代水泥基材料大量使用矿物掺合料,使得关于水泥石微观结构演变特征的研究变得更加复杂。本实验充分考虑材料氧化物组成和含量,计算出硅酸盐水泥、粉煤灰和矿渣的水化速率参数,并代入HYMOSTRUC3D模型中建模,同时考虑水灰比和矿物掺合料的影响,建立了水泥、C-S-H、CH、水化热、孔隙率、孔径分布等随水化龄期的变化关系,获取了水泥水化过程中微观结构的演变信息。基于在HYMOSTRUC3D中所建模型获取了CH和C-S-H的含量,并与XRD测试结果和CEMHYD3D模拟结果进行了对比;考虑了CH在水泥水化过程中的产生以及与FA或BFS混配形成的水泥基材料中的消耗;并模拟研究了不同掺量的活性矿物掺合料对水泥水化放热的影响;同时,预测了水灰比对孔隙率和孔径分布的影响以及孔隙率和孔径分布随时间的变化规律。研究结果表明:HYMOSTRUC3D模拟结果与XRD实验测试结果、CEMHYD3D模拟结果整体吻合较好,验证了所计算水化速率参数和所建立模型的准确性。同时还发现,FA或BFS的掺入可消耗水泥水化产生的CH,且可有效控制水泥基材料的水化放热,掺量越大,消耗的CH越多,控热效果越明显。此外,水灰比越大的水泥浆孔隙率越大,大孔越多,孔径分布越宽。

The mineral admixtures used in modern cement-based materials make the study of the evolution characteristics of cement stone microstructures more complicated.In this paper,the oxide composition and content of the material are fully considered,and the hydration rate parameters of Portland cement(PC),fly ash(FA)and blast furnace slag(BFS)are calculated and substituted into the HYMOSTRUC3D software for modeling.With considering the influence of water-cement ratio and mineral admixture,the relationship between cement,C-S-H,CH,hydration heat,porosity,pore size distribution with the hydration age were established and the evolution of microstructure during cement hydration was obtained.The contents of CH and C-S-H were obtained based on the model established in HYMOSTRUC3D,and compared with XRD test results and CEMHYD3D simulation results.The generation of CH in cement hydration process and the consumption of cement-base materials mixed with FA or BFS were considered.And the effects of different amounts of active mineral admixtures on cement were simulated and studied.At the same time,the influence of water-cement ratio on porosity and pore size distribution and porosity and pore size distribution over time were predicted.The results show that the simulation results of HYMOSTRUC3D are in good agreement with the XRD test results and the CEMHYD3D simulation results,which verifies the calculated hydration rate parameters and the established model.The study also found that the incorporation of FA or BFS can consume CH produced by cement hydration,and can effectively control the hydration heat release of cement-based materials,the larger the dosage,the more CH consumed,and the more obvious the heat control effect.In addition,the larger the water-cement ratio,the larger the porosity of the cement stone,the more the macropore,and the wider the pore size distribution.