1. Background Cement strength is the core indicator of cement quality and a fundamental guarantee of structural safety in construction projects. The updated GB/T 17671-2021 “Method of Testing Cements – Determination of Strength (ISO Method)” officially came into effect on July 1, 2022, replacing the 1999 edition. This revision systematically improves testing equipment requirements, operational procedures, and data processing methods, making China’s cement strength testing more scientific and closely aligned with ISO international standards. 2. Key Changes in the New Standard 1. Stricter Equipment Requirements Higher precision requirements for mortar mixers, jolting apparatus, and compression testing machines Enhanced requirements for structural rigidity and stability Mandatory calibration and performance verification 2. More Standardized Procedures Clear specifications for mixing water quality Standardized cement mixing procedures Detailed specimen moldi...