Test Method For Slump: A Comprehensive Guide for Concrete Mixtures

1. Slump Test Equipment and Procedure
Use a trumpet-shaped slump bucket with specific dimensions: 100mm upper opening, 200mm lower opening, and 300mm height. Fill the bucket with concrete in three equal installments. After each layer, strike the bucket wall 25 times with a tamping hammer, moving from outside to inside for even compaction. Level the concrete surface after tamping, then lift the bucket vertically. The concrete will slump under its weight; measure the height difference between the bucket (300mm) and the slumped concrete. This difference equals the slump value (e.g., 10mm slump if the difference is 10mm).
2. Factors Influencing Slump Selection
Determine the appropriate slump based on multiple factors. Consider the building’s structural section, steel reinforcement density, transportation distance, pouring method, transportation mode, vibration capacity, and climatic conditions. When designing mix proportions, prioritize a smaller slump to optimize performance while minimizing material waste. This approach ensures compliance with structural requirements and environmental standards.

3. Application Scope of the Slump Test
The slump test suits concrete mixtures with high fluidity. It applies to mixes with a slump value ≥10mm and aggregate particle size ≤40mm. For mixtures with slump ≤50mm or dry, hardened concrete with Weibull consistency >30s, use the Consolidation Factor Method instead. This differentiation ensures accurate consistency assessment across diverse concrete types, supporting quality control in production and construction.
As a concrete admixture source production factory, we emphasize standardized testing to enhance mixture performance. Contact us for tailored solutions that integrate advanced admixtures with precise slump control, optimizing both workability and sustainability in your projects.