Safe Construction Even in Cold and Rainy Weather... Revision of Concrete Standard Specifications and Design Criteria

Quality Control in Low-Temperature Environments, Principle Prohibition of Pouring During Rainfall
Specific On-Site Measures

When crossing the Banpo Bridge in Seoul, you can see new apartments, old apartments, and apartments under construction all at once in the Sinbanpo area. The new apartments on the left are Acro Riverview Sinbanpo, the low old apartments on the right are Sinbanpo 2nd Complex, and the apartments under construction in the back are the Maple Xi construction site. Photo by Younghan Heo younghan@

On the 17th, the Ministry of Land, Infrastructure and Transport announced that it will revise the concrete construction standards to be observed on-site to ensure quality when carrying out concrete work in low-temperature environments below 4℃ on average per day and on rainy days. Through this, the standard specifications and design criteria have been updated to strengthen the safety of construction structures such as apartments and buildings.

First, reflecting the characteristics of concrete that cannot fully develop strength in low-temperature environments, an additional strength of 6 megapascals (MPa) must be secured. In addition, the maximum usage ratio of admixtures that hinder concrete strength development in low temperatures has been reduced. For fly ash, it has been reduced from 30% to 15% or less, and for blast furnace slag, from 50% to 30% or less.

However, if it is proven that the target strength can be secured by using new materials or technologies, the criteria for temperature-corrected strength or admixture usage ratio can be exceptionally adjusted with the approval of the responsible engineer.

Considering the harmful effects of rain and snow on the strength and durability of concrete, work standards have been strengthened. Concrete pouring is prohibited when there is concern about quality degradation due to rain. If pouring is unavoidable, measures to prevent quality deterioration caused by moisture ingress must be taken, and approval from the responsible engineer is required, strengthening the standards.

To prevent confusion at construction sites, a specific rainfall criterion (3mm per hour or less) and a 'Concrete Pouring Guideline During Rainfall' have been newly established to allow on-site judgment of whether to pour concrete, providing detailed guidance on pre- and post-rainfall step-by-step measures. Sites where concrete work must proceed under rainfall of 3mm per hour or less must follow this guideline.

On-site curing specimens must be produced and tested when pouring concrete at construction sites. Until now, on-site curing specimens were produced only when requested by the responsible engineer as needed, but with this revision, production is mandatory at all sites.

This revision was prepared through the operation of a revision consultative body (Korea Institute of Civil Engineering and Building Technology, Korea Concrete Institute, construction and ready-mixed concrete industries), conducting practical verification research, and gathering opinions from related organizations and associations. The full text of the revision can be found on the Ministry of Land, Infrastructure and Transport website under 'Policy Data - Legal Information - Administrative Notice.' Opinions will be collected until the 26th, and the notice is scheduled to be promulgated within the year.

Kim Taebyeong, Director of Technology Safety Policy at the Ministry of Land, Infrastructure and Transport, said, “Concrete quality management is essential to ensure the safety of construction structures such as housing, bridges, and tunnels. We have collected and supplemented opinions multiple times through various channels to increase on-site acceptance.” He added, “We ask that the field pay close attention to comply with the newly introduced revised standards so that construction work can be carried out more safely.”

This content was produced with the assistance of AI translation services.