Fire represents one of the significant hazards encountered by civil infrastructures, and thus providing appropriate fire safety measures is a major requirement in a building design for ensuring the safety of the occupants. Minimizing fire-induced damage and collapse of structural systems are the primary objectives in the design of concrete structures. An experimental investigation has been carried out to examine the mechanical properties such as compressive, tensile and flexural strengths of concrete exposed to elevated temperature following standard fire curve as per ISO 834. Capacity-based standards have been formulated to predict the residual strength of various grades of concrete exposed to various duration of heating. Stress strain behaviour, elastic modulus, weight loss, spalling and thermal crack pattern of specimens were also investigated. Water–cement ratio and porosity of concrete were found to be the critical factors for strength loss of concrete. A relationship is established between weight loss and strength loss of concrete. Higher grades of concrete were found to have more weight and strength loss than those of lower grades.

中文翻译：

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高温下混凝土的火灾后损坏评估和基于容量的建模

火灾是民用基础设施面临的重大危害之一，因此提供适当的消防安全措施是确保居住者安全的建筑设计的主要要求。最大限度地减少火灾引起的结构系统损坏和倒塌是混凝土结构设计的主要目标。根据 ISO 834 的标准火灾曲线，进行了一项实验研究，以检查暴露在高温下的混凝土的力学性能，如压缩、拉伸和弯曲强度。 已经制定了基于容量的标准来预测各种等级的残余强度暴露于不同加热时间的混凝土。还研究了试样的应力应变行为、弹性模量、重量损失、剥落和热裂纹模式。发现混凝土的水灰比和孔隙率是混凝土强度损失的关键因素。在混凝土的重量损失和强度损失之间建立了关系。发现较高等级的混凝土比较低等级的混凝土具有更多的重量和强度损失。