Current specification requirements for concrete expansion agent are an important verification basis in the engineering material selection process. All incoming products must meet all mandatory indicators of the corresponding standards. The core standard currently implemented is "Concrete Expansion Agent" GB 23439-2009, and all testing and application of compliant products are based on this standard. To determine whether a concrete expansion agent meets current specifications, you can directly refer to three verifiable hard standards: Qualified chemical composition and stability indicators: Magnesium oxide content ≤5%, alkali content…