Effect of temperature on fracture toughness of plain cement concrete

Concrete is widely used as a primary structural material. In structures like cooling towers in thermal power stations and pressure vessels in nuclear power plants, concrete is subjected to high temperatures. Fire in buildings, structures and tunnels etc., also contributes to high temperature in concrete members. The exposure of concrete to elevated temperatures affects its properties, mostly decreases the compressive, tensile and flexural strengths of concrete. Appropriate information about the mechanical properties of concrete such as strength, stiffness, toughness and brittleness is inevitably required to design these structures. Besides this, determining the flexural toughness is very useful in assessment of behaviour of the structures under various loading and environmental conditions and assessing post fire safety of concrete structures.