高温下耐火浇注料和结构混凝土的单相混合配方
Towards a single-phase mixed formulation of refractory castables and structural concrete at high temperatures
摘要：
结构材料广泛用于核容器、高温工艺和民用建筑等应用。通常，在它们的放置和使用寿命期间，它们可能在其结构中呈现自由或化学键合的液相，当暴露于高加热速率时需要仔细注意。它们在这种条件下的行为是一个具有挑战性的问题，因为它包括许多高度非线性特性（不易通过实验测试测量），强耦合方程和不可靠的实验基准。尽管如此，这样的模拟还是很有意义的。这项工作的目的是提供一个数值研究，检查其解决方案是否确实收敛，并产生可靠的结果。此外，由于该模型需要几个输入参数，这项工作进行了敏感性分析，并评估其适用于更复杂的情况下，因为这些问题仍然在文献中开放。为了做到这一点，提出了一个简单的模型，可以很容易地适应混合配方和复杂的几何形状。有人发现，当考虑一维模型的选择有关的吸附等温线的插值是不必要的系统的数值稳定性。此外，材料的渗透率和导热系数是影响压力、温度和可蒸发水含量剖面模拟结果的重要参数。最后，聚合物纤维混凝土的二维细观模拟（基于混合配方的问题）产生的结果与实验观察。因此，本文提出的模型可以为未来的工作提供坚实的基础，也是对更简单的方法的重要见解。
英文摘要：
Structural materials are broadly used in applications such as nuclear vessels, high-temperature processes, and civil construction. Usually, during their placing and lifespan, they may present free or chemically bonded liquid phases in their structure, demanding careful attention when exposed to high heating rates. Their behavior in such conditions is a challenging problem as it comprises numerous highly nonlinear properties (not easily measured via experimental tests), strongly coupled equations and unreliable experimental benchmarks. Nonetheless, such simulations are of great interest. This work aims to provide a numerical study, checking whether its solution indeed converges and yields reliable results. Additionally, as the model needs several input parameters, this work conducts a sensitivity analysis and also assesses its applicability to more complex scenarios, as such issues remain open in the literature. In order to do that, a simple model that can be easily adapted for mixed formulations and complex geometries was proposed. It was found out that when considering unidimensional models the choices regarding the interpolation of the sorption isotherms are not essential to the numerical stability of the system. Besides that, the permeability and thermal conductivity of the material are the most important parameters that affect the simulation results of pressure, temperature and evaporable water content profiles. Finally, the 2D mesoscale simulation of concrete with polymeric fibers (based on the mixed formulation of the problem) yielded results that agreed with experimental observations. Thus, the model proposed herein can provide a solid base for future works and also important insights towards simpler methodologies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
