Plioplys Linas, Kudžma Andrius, Antonovič Valentin, Gribniak Viktor
Laboratory of Innovative Building Structures, Vilnius Gediminas Technical University, Sauletekio Av. 11, LT-10223 Vilnius, Lithuania.
Laboratory of Composite Materials, Vilnius Gediminas Technical University, Linkmenu Str. 28, LT-08217 Vilnius, Lithuania.
Materials (Basel). 2025 Mar 14;18(6):1282. doi: 10.3390/ma18061282.
Calcium aluminate cement-based castables were developed in the early 1990s for the metallurgical and petrochemical industries, exhibiting exceptional mechanical resistance when heated over 1000 °C. In typical operation conditions, they withstand compressive stresses due to high temperatures and mechanical loads. The extraordinary material performance has led to interest in using these materials for developing building protection systems against fires and explosions. This application requires structural reinforcement to resist tensile stresses in the concrete caused by accidental loads, making the bonding of reinforcement crucial. The different temperature expansion properties of the castables and reinforcement steel further complicate the bonding mechanisms. This manuscript belongs to a research project on developing refractory composites for civil infrastructure protection. In previous studies, extensive pull-out tests evaluated various combinations of refractories and reinforcement types to determine the most efficient candidates for refractory composite development. Thus, this study employs ribbed stainless Type 304 steel bars and a conventional castable, modified with 2.5 wt% microsilica for a 100 MPa cold compressive strength. It uses the previous pull-out test results to create a numerical model to predict the bonding resistance of the selected material combination. Following the composite development concept, this experimentally verified model defines a reference for further developing refractory composites: the test outcome of a new material must outperform the numerical prediction to be efficient. This study also delivers an empirical relationship between the castable deformation modulus and treatment temperature to model the reinforcement pull-out deformation in the composite heated up to 1000 °C.
铝酸钙水泥基浇注料于20世纪90年代初开发，用于冶金和石化行业，在加热到1000°C以上时表现出卓越的机械抗性。在典型的运行条件下，它们能承受高温和机械负荷引起的压应力。这种非凡的材料性能引发了人们对将这些材料用于开发防火防爆建筑保护系统的兴趣。此应用需要进行结构加固，以抵抗意外荷载在混凝土中引起的拉应力，因此钢筋的粘结至关重要。浇注料和钢筋不同的热膨胀特性使粘结机制更加复杂。本手稿属于一项关于为民用基础设施保护开发耐火复合材料的研究项目。在之前的研究中，通过大量的拉拔试验评估了耐火材料和钢筋类型的各种组合，以确定耐火复合材料开发的最有效候选材料。因此，本研究采用带肋的304型不锈钢钢筋和一种常规浇注料，该浇注料用2.5 wt%的微硅粉改性，冷态抗压强度为100 MPa。它利用之前的拉拔试验结果创建一个数值模型，以预测所选材料组合的粘结抗性。遵循复合材料开发理念，这个经过实验验证的模型为进一步开发耐火复合材料定义了一个参考标准：一种新材料的测试结果必须优于数值预测才能有效。本研究还给出了浇注料变形模量与处理温度之间的经验关系，以模拟加热到1000°C的复合材料中钢筋的拔出变形。
