Steel is not adversely affected by weather, easy to erect, strong and durable with low weight. Its main function is in the formation of a skeleton that holds the whole structure. The components for concrete, that is, cement, sand and aggregates are easily available and affordable worldwide making allowing preference for concrete structures. From research and studies, concrete has been realized to be brittle, strong in compression and weak in tension. From these properties, modalities of improving it have been designed. The most currently used modality is its reinforcement. Reinforced concrete therefore has been realized to withstand tension and compression leading to its durability and use in many structures.
The study and test of steel for industrial construction has been done for many years. Its properties led to its popular use since the early 1990’s. Due to this demand, designs for steel structures have been implemented. The main factor that has driven the designs is earthquake disasters. Its design has evolved from stiffer approach to flexibility and ductility. During the 1970’s, proven formulas were used to design steel structures. Advanced technology through Computer Aided Design has improved designing work with building codes controlling the steel industry. Working stress design was the main factor for consideration in concrete members since 1960s. Strength design method was adopted by the International Building Code (IBC) in its 1956 edition. The concepts considered are strength needed inclusive of the load and strength of the design with an aim of achieving durable structures. The designs lead to increased costs in construction with reduced maintenance costs. ...Show more