Shocking Comparative Test Results of Chinese and South Korean Cement!!
Recently, the comparative test results of Chinese and South Korean cement conducted by South Korean media have caused a stir in the industry.
South Korean journalists obtained various Chinese cement samples through a Chinese friend in April this year, and conducted comparative experiments with cement available on the South Korean market, finding significant differences between the two in terms of color, smell, and content of harmful substances.
The test results showed that Chinese cement is normally gray, while South Korean cement has a yellowish color. After mixing with water, the color difference becomes more pronounced, and the color difference in the hardened concrete remains obvious. More notably, after hardening, the side of the South Korean cement shows difficult-to-remove strange spots.
The results of the smell test were even more surprising. The concrete made from Chinese cement has almost no smell, while the South Korean cement products emit a strong foul odor. After sealing the pure cement blocks in an airtight container for three days, the South Korean blocks released an "unpleasant, unprecedented" stench, which lasted for several days; the Chinese blocks only emitted a slight stone-like smell.
The journalist conducting the test pointed out that it is possible to verify without professional equipment: mix South Korean cement with water to make small concrete blocks, dry them, and then place them in a stainless steel airtight container. After 2-3 days, opening the container will allow you to smell a strong chemical odor. This phenomenon raises doubts about the source of chemical odors in South Korean residential environments — it may not only come from chemical additives, but also be related to the composition of the cement itself.
According to the test report from the Korean Institute of Chemical Convergence Testing (an environmental ministry-certified institution) (June final report): except for chromium content being similar, South Korean cement has significantly higher levels of harmful substances such as lead, nickel, copper, and arsenic compared to the Chinese samples. The difference in fluoride content is particularly notable — South Korean cement reaches 1418 mg/kg, while the Chinese samples are only 588 mg/kg and 337 mg/kg respectively.
Analysis points out that this difference stems from fundamentally different raw material ratios:
South Korean cement plants use large amounts of various industrial waste as alternative raw materials, including waste tires, waste plastics, waste synthetic resins, waste oil, and other combustible wastes, as well as fly ash, sewage sludge, and sludge containing hazardous chemicals from semiconductor factories, non-combustible wastes. The harmful components such as fluorides in these wastes ultimately remain in the cement products.
Experts in the South Korean industry stated that the test results reveal potential environmental health risks associated with the use of industrial waste in building materials, and called for strengthening the regulation of building material safety standards and the transparency of production processes.
Original article: www.toutiao.com/article/1843280776167562/
Statement: The article represents the views of the author.