The paper describes an experimental behaviour of the basalt fibre reinforced polymer composite by external strengthening to the concrete beams. The BFRP composite is wrapped at the bottom face of R.C beam as one layer, two layers, three layers and four layers. The different characteristics – are studied in – first crack load, ultimate load, tensile and compressive strain, cracks propagation, crack spacing and number of cracks etc. To – investigate, total of five beams size 100×160×1700 mm were cast. One beam is taken as control and others are strengthened with BFRP composite with layers. From this investigation, the first crack load is increased depending on the increment in layers from 6.79% to 47.98%. Similarly, the ultimate load carrying – capacity is increased from 5.66% to 20%. The crack’s spacing is also reduced with an increase in the number of layers.

The FRP reinforcement gained importance due to high tensile strength, high durability and ecological friendliness [1–7]. Its usefulness as the internal or Near Surface Mounted reinforcement in bent concrete elements has already been proven. Though, in terms of the compressive behaviour of the bars and concrete elements incorporating them, there are still few experimental and numerical considerations, especially when high temperatures are considered. This article contains further considerations on the performance of concrete columns with BFRP main reinforcement in fire resistance tests on the basis of previously presented authors’ numerical analyses. Comparative analysis in terms of temperatures, deformations and stresses of concrete columns with BFRP and steel main reinforcement in fire resistance tests is presented by the example of two columns, for which also experimental investigations were performed. Also, a comparative analysis of stress-strain relations for BFRP, steel and concrete at temperatures up to 600°C is presented. It can be concluded that BFRP bars’ properties are strongly different when compressive and tensile performance is considered, especially at elevated temperatures. Tensile strength was higher for BFRP than steel at room temperature, but along with temperature growth, it came the other way (at around 600°C). The compressive strength of the BFRP bars was higher than the value for concrete, but only for temperatures lower than 200°C.