Refractories are materials designed to work at high temperatures, and are applied in steel making, cement making, aerospace engineering, and other fields where a combination of chemical and mechanical stability is paramount. Due to such high temperature applications, creep strains play an important role in the mechanical performance of refractories, that often present an asymmetric behavior, i.e., different creep strain rates under tension and compression. The aim of this work is to propose an asymmetric creep model that can be used to simulate the time-dependent non-linear primary and secondary creep behavior of refractories at high temperature. The proposed model uses a split of the stress tensor into positive and negative parts and further calculation of the contribution of each stress sign to the overall strain rate using a weighted average over the equivalent stresses. An experimental procedure is proposed in order to identify the tensile and compressive parameters of an alumina-spinel refractory used in steel ladle linings, using a Brazilian test and a subset-based Digital Image Correlation (DIC) technique, for a temperature of 1300 °C.

耐火材料是设计用于在高温下工作的材料，应用于炼钢、水泥制造、航空航天工程和其他需要化学和机械稳定性相结合的领域。由于这种高温应用，蠕变应变在耐火材料的机械性能中起着重要作用，通常呈现不对称行为，即在拉伸和压缩下的不同蠕变应变率。这项工作的目的是提出一种非对称蠕变模型，该模型可用于模拟高温下耐火材料随时间变化的非线性一次和二次蠕变行为。所提出的模型将应力张量拆分为正负部分，并使用等效应力的加权平均值进一步计算每个应力符号对整体应变率的贡献。为了确定钢包内衬中使用的氧化铝-尖晶石耐火材料的拉伸和压缩参数，使用巴西测试和基于子集的数字图像相关 (DIC) 技术，在 1300 °C 的温度下，提出了一种实验程序.