It is expected that the reliability of concrete quality will increase by preparing ‘unit quantity quality inspection standards’ to eradicate inappropriate use of ready-mixed concrete in construction sites.
The Ministry of Land, Infrastructure and Transport (Minister Hee-ryong Won Won) announced on September 1, 22nd, KCS 14 20 00 (Standard Specification for Concrete Construction) with the aim of ‘preparing unit quantity quality inspection standards’ to enhance the quality of concrete, the most widely used construction material. said.
* 1 m of concrete that has not yet hardened3 Factors that directly affect the quality of concrete such as strength and durability of concrete by the amount of water contained in it (excluding the quantity in aggregate)
In the meantime, for reasons such as constructability and cost reduction, there has been a deep-rooted practice in some construction sites, such as adding water to concrete and manipulating the mix. However, although the construction standards set the allowable value of the unit quantity to correct this problem, the concrete test standards are not stipulated, so the problem of deterioration of concrete quality has been continuously raised.
* (Existing) The maximum unit quantity is 185kg/㎥, and it is used as little as possible within the workable range, and the amount must be determined through testing.
Accordingly, the Ministry of Land, Infrastructure and Transport, together with the National Construction Standards Center (Korea Institute of Construction Technology) and the Korea Concrete Society, established the ‘Unit Quantity Quality Inspection Standard’ as the main focus of KCS 14 20 00 (Concrete Construction Standard Specification) in order to strengthen concrete quality control such as prevention of defective ready-mixed concrete. ), and in addition, this revision includes the definition of the average daily temperature for the application of Korean-Chinese concrete in the winter season and the criteria for the end of initial curing, and the specification of the time and method of reinstallation of Dongbari.
In the unit quantity quality inspection standards, the test/inspection method, inspection period and frequency, and judgment criteria are specifically included to enable reliable inspection. was made possible.
* Considering urgency and field applicability, it may be added according to future technology development and research.
Lee Sang-il, director of technology and safety policy at the Ministry of Land, Infrastructure and Transport, said, “It is expected that both manufacturers and sites will be able to induce reasonable quality management through the preparation of unit quantity quality inspection standards.
The full text of the revision (3 codes including KCS 14 20 10) and the ‘Concrete Society Standard’, which provides a method for measuring unit quantity, can be found on the website of the National Construction Standards Center (www.kcsc.re.kr) from September 1st.
