Concrete is a material often used in the construction of high rise buildings, railroad and road tunnel constructions. There is an important problem influence of high temperatures on concrete that affects serviceability and rehabilitation of buildings. In the case of unexpected fire or subjecting concrete to a higher temperature, the building concrete elements such as columns, slab and walls will be subjected to extreme temperatures this leads to severe deterioration and it undergoes a number of transformations and reactions, thereby causing progressive breakdown of cement gel structure, reduced durability, increased tendency of drying shrinkage, structural cracking and associated concrete color changes. In order to assess the performance of reinforced concrete members it is important to understand the changes in the concrete properties due to extreme temperature exposure. This thesis studies the effect of elevated temperatures on the mechanical properties of lightweight, vesicular basalt and limestone concrete. Samples from three different concrete mixes with scoria, vesicular basalt and limestone coarse aggregates were prepared. Temperature range from 300°C to 900°C were used with intervals of 300°C for exposure durations of 4, 8 and 24 hours were investigated. This thesis presents the effects of a high temperature on selected physical properties of concrete including color change, spalling, and weight losses which are determined after air cooling.In addition, changes to mechanical properties are discussed: stress-strain relationship and compressive strength for each types of aggregate, temperature range and exposure duration. Test results indicate that weight of the specimen significantly reduced with an increase temperature. Types of aggregate on losses in weight were not found to be significant. Concrete made of scoria coarse aggregate showed higher mechanical properties at all temperatures, followed by vesicular basalt and limestone concretes. It is shown that at elevated temperatures, the concrete strength is significantly reduced, whereas the strain at peak stress and ultimate strain are increased.