SC Construction

Steel-Concrete Composite (SC) construction is a form of modular construction which comprises of two steel faceplates that are internally connected to create a sandwich panel. The faceplates provide permanent shuttering during concrete infill pouring and generate strength through composite action once the concrete has cured. Many attempts have been made over the past 25 years to devise simple, safe and rapid fabrication methods to internally connect the faceplates however the approaches devised are generally labour intensive since they involve internally welding ribs, bar and trusses to connect the faceplates. When the concrete cures, this internal scaffolding ensures composite action between the steel faceplates and the concrete core. The addition of headed shear studs to the arrangements prevents local buckling of the faceplates and ensures sufficient strength at the steel-concrete interface to generate composite behaviour.

Generic Advantages of SC off Site Modular Construction

The generic advantages of off-site Modular SC construction over conventional on-site reinforced concrete construction are similar for all forms of SC deployment.

Quality, Accuracy, Tolerance

Manufacturing off-site in factory-controlled conditions enables far higher quality control, accuracy and tolerance adherence than can be achieved on site when exposed to the vagaries of the weather.

Stable workforce

A skilled and trained workforce operating in the same location offers up greater benefits for the local community.


Efficiencies can be gained by repetitive tasks being undertaken by the same teams rather than a team thrown together on site for the first time.

Benefits for Every Level of the Supply Chain

Developer Benefits

There is an opportunity to achieve extra rental income and reduce financing costs through earlier project completion. If the developer is selling residential units earlier sales can be achieved. SC modular cores are slimmer than their concrete counterparts thereby increasing the lettable floor area and therefore the capital value.

Architects and Engineers Benefit

The modular panels have the ability to be erected in confined spaces or from one side – especially beneficial in city centre party wall situations. With it being mainly off–site the environmental impact is lower and the structure reliably accurate.

Main Contractor Benefits

SC Modular Construction eliminates temporary formwork and all that comes with it – rebar fixers, lay down areas, tidier and safer sites with faster and more accurate construction. Sourcing an SC modular core through a steelwork contractor reduces the supply chain – one BIM model, fully co-ordinated through a single sub-contractor.

Sub-Contractor Benefits

Owning and managing the core offers greater ease of attachment for the structural steelwork sub-contractor. The increased accuracy and better tolerances make construction faster, simpler and safer. The battle over hook time in heavily congested and tight city centre sites disappears.

Nuclear Applications

Most buildings and containment structures in nuclear power plants (NPP) have been built from reinforced or post-tensioned concrete in the past. This has placed heavy reliance on cast in-situ construction. It has led to lengthy site operations to accommodate the time spent in assembling the shuttering and reinforcing steel and stripping the shuttering after curing of the concrete. Attachments to the walls and floors which are used to support electrical and mechanical equipment (e.g. piping, cable trays, etc.) generally require the installation of embedded steel plates in the walls (there are around 100,000 plates in a typical NPP) or, if acceptable, concrete expansion anchors into walls, floors and ceilings . Installing embedded steel plates is difficult because anchor rods and their end plates need to be inserted within very dense reinforcement, requiring the displacement of the reinforcement bars. If post-installed anchors are permitted, then this can also be a time-consuming process that involves first locating the reinforcing bars in the concrete to avoid cutting them. This is followed by drilling into the concrete and inserting anchors for bolting steel plates to the concrete surface to attach supports.

Most Nuclear Power Plant Vendors have been developing modular construction techniques that make greater use of pre-fabrication and factory assembly components that reduce reliance on site activity. A modular build approach has already been deployed to assemble the main structures on a large nuclear plant. However, because of their size, small reactors are particularly suited to modularisation with the potential for repeat volume standard components and in that respect, SC steel-concrete modular construction is well suited to Small Modular Reactors (SMRs).