Structural steels are used in most large construction projects, such as buildings and bridges, in the form of girders etc. The performance of the steel is vital to maintain the required integrity. High temperatures are known to weaken steel, which begins to soften at around 425°C and loses about half of its strength at 650°C. At these temperatures, the steel will begin to buckle and twist if subject to high loads, which will impede structural integrity. Consequently, engineers must take into account the environmental temperature range that a structure will be subject to over its life span.