Which Performance Indicators Should Be Tested Before UHPC Components Leave the Factory?

Before leaving the factory, UHPC components must be tested for five core categories of indicators: mechanical properties, dimensional deviation, appearance quality, durability, and embedded part performance. Qinglong has established a full-chain testing system covering "raw materials - production process - finished products," equipped with a CMA-accredited laboratory, ensuring that every batch of products leaves the factory 100% qualified, meeting the stringent safety and quality requirements of construction projects.

1. Mechanical Property Testing: Ensuring Structural Safety

Mechanical properties are the core guarantee of a component's load-bearing capacity, with three mandatory test indicators. Compressive strength: tested using 100mm×100mm×100mm specimens, 28-day compressive strength ≥120MPa (standard type) and ≥150MPa (high-strength type); Qinglong samples 3 specimens per batch, with a testing pass rate of 100%. Flexural strength: tested using 100mm×100mm×400mm specimens, 28-day flexural strength ≥15MPa (standard type) and ≥20MPa (high-strength type); Qinglong's high-strength UHPC achieves a measured flexural strength of 22-25MPa. Elastic modulus: 28-day elastic modulus ≥45GPa (standard type) and ≥50GPa (high-strength type), ensuring that component deformation meets design requirements; Qinglong's standard UHPC maintains a stable elastic modulus of 48-52GPa. Testing standards: performed in accordance with Ultra-High Performance Concrete (GB/T 31387); Qinglong's laboratory testing equipment achieves a precision of ±1%, providing authoritative and reliable data.

2. Dimensional Deviation and Appearance Quality Testing: Ensuring Installation and Decorative Effects

Dimensions and appearance directly affect installation compatibility and visual effects. Dimensional deviation: length ≤3m deviation ±2mm, length >3m deviation ±3mm; width deviation ±2mm; thickness deviation ±1mm; flatness error ≤1mm/m. Qinglong uses laser rangefinders for testing, and components exceeding deviation limits are 100% reworked. Appearance quality: the surface must be free of cracks (width ≥0.1mm is non-conforming), honeycombing, pitted surfaces, exposed reinforcement, and other defects, with blemish area ≤0.5% of total surface area; Qinglong uses bright-light inspection plus tactile inspection, achieving a 100% defect repair rate. Color and texture: color uniformity ΔE≤3 (CIE Lab standard) and texture consistent with samples; Qinglong uses colorimeters for testing, and components exceeding color difference limits are replaced unconditionally. Joint seams: jointing surface dimensional deviation of precast jointed components ≤±1mm to ensure smooth on-site assembly; Qinglong conducts trial assembly testing before jointed components leave the factory.

3. Durability and Embedded Part Performance Testing: Ensuring Long-Term Stability

Durability and embedded part performance determine the service life of components, with selective testing based on the project environment. Durability testing: in ordinary environments, test the impermeability grade (≥P25) and freeze-thaw cycle resistance (≥300 cycles, strength loss ≤5%); in coastal/industrial environments, additionally test the chloride ion penetration coefficient (≤1.0×10⁻¹²m²/s) and sulfate corrosion resistance; Qinglong's UHPC in coastal projects achieves an impermeability grade of P30. Embedded part performance: test embedded part materials (spectral analysis), anchorage force (pull-out test, anchorage force ≥1.2 times the design value), and anti-corrosion coating thickness (galvanized layer ≥85μm; stainless steel has no anti-corrosion coating requirement); Qinglong's embedded part pull-out test pass rate reaches 100%. Other testing: special-function components (e.g., fire-resistant, wear-resistant) require additional testing of corresponding indicators—fire-resistant components have a fire resistance limit ≥1.5 hours, and wear-resistant components show wear loss ≤0.3kg/m² after 500 revolutions; Qinglong customizes testing plans according to project requirements.

4. Testing Process and Enterprise Standards

Qinglong has established a standardized testing process to ensure comprehensive and precise testing. Sampling rules: 3 components are sampled from each production batch (≤50 units) for finished product testing, and raw materials (cement, fibers, aggregates) are tested upon each batch's arrival. Testing records: testing logs are maintained, recording specimen numbers, test data, testing personnel, and testing dates, with a retention period ≥10 years and 100% traceability. Conformity determination: only when all tested indicators comply with the General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC) (Plan No. 2024-0232T-JC) and project technical requirements can a factory certificate of conformity be issued; non-conforming components are strictly prohibited from leaving the factory. Laboratory support: Qinglong's laboratory is equipped with a complete set of equipment, including compression testing machines, flexural testing machines, laser rangefinders, colorimeters, and chloride ion penetration instruments, holds CMA accreditation, and its testing data has legal validity.