This method induces higher costs on the overall project, however, due to the higher cost of the epoxy coated bars. 9 Some reinforcing bars are coated in epoxy as a second order measure of preventing corrosion due to water contact. If the concrete cracks, it provides a path for water to travel directly to the reinforcing bars.
This cover distance must be specified because concrete will inevitable crack at locations carrying tension, or locations containing reinforcing bars for the purpose of carrying said tension. Fire resistance – Concrete has excellent fire resistance properties, requiring no additional construction costs to adhere to the International Building Code (IBC) fire protection standards. Approximately half of the cost of using reinforced concrete in a structural project is attributed to the construction of the form-work.
Concrete reinforced with steel rebar give the structure a stronger tensile capacity, as well as an increase in ductility and elasticity. Corrosion – When choosing a structural material, it is important to consider the life cycle of the building. Special considerations must be taken into account with structural steel to ensure it is not under a dangerous fire hazard condition.
Sustainability – Many construction companies and material vendors are making changes to be a more environmentally friendly company. 7 Due to the fact that steel is sold by weight it is the responsibility of the structural designer to specify the lightest members possible while still maintaining a safe structural design. Most commercial and industrial structures are primarily constructed using either structural steel or reinforced concrete When designing a structure, an engineer must decide which, if not both, material is most suitable for the design.
In terms of a load bearing structural frame, they will generally consist of structural steel, concrete , masonry , and/or wood, using a suitable combination of each to produce an efficient structure. The standard that covers CE Marking of structural steelwork is EN 1090 -1. The standard has come into force in late 2010. Because steel components are “safety critical”, CE Marking is not allowed unless the Factory Production Control (FPC) system under which they are produced has been assessed by a suitable certification body that has been approved to the European Commission.
The standard commonly used structural steels are: 3. The four-number AISI steel grades commonly used for mechanical engineering, machines, and vehicles are a completely different specification series. The normal yield strength grades available are 195, 235, 275, 355, 420, and 460, although some grades are more commonly used than others e.g. in the UK, almost all structural steel is grades S275 and S355.
The steel manufacturing process shall be at the discretion of the steel producer. EN10219-1 specifies the technical delivery conditions for cold formed welded structural hollow sections of circular, square or rectangular forms and applies to structural hollow sections formed cold without subsequent heat treatment. In these examples, ‘S’ denotes structural rather than engineering steel; 275 or 355 denotes the yield strength in newtons per square millimetre or the equivalent megapascals ; J2 or K2 denotes the materials toughness by reference to Charpy impact test values; and the ‘W’ denotes weathering steel Further letters can be used to designate fine grain steel (‘N’ or ‘NL’); quenched and tempered steel (‘Q’ or ‘QL’); and thermomechanically rolled steel (‘M’ or ‘ML’).