Hyundai Engineering has received technical certification from the Korean Society of Steel Construction for a modular steel joint structural system co-developed with Hyundai Steel (004020). The technology covers joints used to stack and assemble factory-manufactured box-type modules on site. It aims to improve structural safety in high-rise modular construction while simplifying installation. Under seismic design standards for steel structures revised in May 2024, new steel joint technologies require verification by the Korean Society of Steel Construction, designated by the Ministry of Land, Infrastructure and Transport. Hyundai Engineering passed cyclic loading tests using two or more identical specimens and a technical review.
The modular steel joint system replaces built-up rectangular steel tube members, traditionally fabricated by cutting and welding steel plates, with standardized, off-the-shelf H-beams. This approach reduces costs, stabilizes material supply and provides uniform section quality. H-beams also simplify fireproof coating application. For installation, a two-way alignment guide positions crane-lifted modules and absorbs alignment errors within a set range in both horizontal directions. A horizontal bolting method allows workers to fasten bolts from the front rather than inside cramped ceilings or columns, improving access for power tools and worker safety. The company said this method reduces on-site assembly time by more than 20%.
Researchers from the Korean Society of Steel Construction verified structural performance through cyclic loading tests on a full-scale two-story frame. The system maintained performance without structural damage or strength degradation at a story drift of 4%, double the 2% maximum required under the current Korean Design Standard. Directly transferring building loads to columns also reduces force concentration and leaning. The technology was tested at H-Modular Lab, a full-scale facility built by Hyundai Engineering and Hyundai Steel in November 2024. Hyundai Engineering plans to expand off-site construction technology into data centers and industrial buildings. “The competitiveness of modular construction depends not only on the precision of factory production but also on how quickly and safely modules can be assembled on site,” an official at Hyundai Engineering said. “This H-beam steel modular joint structural system secures construction tolerance absorption, worker safety and seismic structural performance all at once.”