It has been confirmed that most of the ready-mixed concrete companies that supplied concrete to the construction site of Hwajeong I-Park apartment, which collapsed while under construction on Jan. 11, were found to have been used poor concrete materials during government inspection. It is highly probable that unsuitable concrete was used at the site of the collapsed apartment as the time of inspection overlaps with the construction period of Hwajeong I-Park.
According to the last year’s inspection result of ready-mixed concrete manufacturing plants nationwide submitted to People Power Party Rep. Kim Eun-hye by the Ministry of Land, Infrastructure and Transport on Wednesday, eight in 10 companies that supplied concrete to the construction site of Hwajeong I-Park apartment were found to be unfit.
In particular, four of them inadequately managed aggregates such as gravels and sand used in concrete, and three of them improperly stored admixtures used to improve concrete strength. Most admixtures are in powder form, which makes them very sensitive to temperature and humidity. Improper storage can lead to deterioration of concrete quality.
On-site inspection was held from July 2020 and May 2021. The collapsed apartment began construction in May 2019. Considering that ready-mixed concrete is used from the frame construction stage right after six months of foundation work, it is highly likely that the concrete produced in unfitted factories was used at the site. “The most important factor that decides the quality of concrete is the quality of aggregates and admixtures. If they were managed poorly, there is a high chance that the concrete failed to set and harden and ended up having low strength,” said Lee Won-ho, former professor of architectural engineering at Kwangwoon University.
The Dong-A Ilbo checked the schedule of work in the construction supervision report of Hwajeong I-Park and found that the frame construction of the collapsed Building 201 was supposed to be completed by December last year. Considering that the frame construction of the building was still underway at the time of collapse, the construction was delayed by more than a month. There are suspicions that HDC Hyundai Development Company put pressure to finish the construction fast.
The Gwangju Metropolitan Police and the Ministry of Employment and Labor in Gwangju on Wednesday conducted a search and seizure of the HDC Hyundai Development Company headquarters in Seoul, Gwangju Seo-gu Office, design offices and rebar suppliers, and secured materials related to the construction of Hwajeong I-Park.
firefly@donga.com · 記者peneye09@donga.com
