The manual flow table test evaluates fresh cement mortar, building lime, and hydraulic binder consistency by applying calibrated dynamic shear energy. Unlike static slump tests that rely purely on a material's self-weight collapse, the manual flow table uses a hand-operated rotary wheel to repeatedly lift and drop a precision-machined platform through a fixed 12.7 mm (0.5 in) vertical height.
This dynamic drop action forces the fresh mortar past its initial movement friction threshold, breaking internal bonds to reveal both yield stress (the initial force required to induce motion) and plastic viscosity (resistance to flow once moving). The resulting flattened spread provides far deeper data regarding batch-to-batch uniformity, water retention, and segregation resistance than static settlement measurements.
Flow Percentage (%) = [(Average Spread Diameter − Original Base Mold Diameter) / Original Base Mold Diameter] × 100
Standardized Manual Testing Method (ASTM C230 / EN 1015-3)
The manual testing sequence relies on exact mechanical dimensions to ensure identical shear energy delivery across laboratory trials:
- Mold Placement: Position the standard brass conical mold (100 mm base × 70 mm top × 50 mm height for ASTM C230, or 60 mm height for EN 1015-3) at the center of the clean 254 mm bronze or 300 mm stainless steel table plate.
- Sample Compaction: Fill the mold in two equal layers with freshly prepared mortar, tamping each layer ten times using the standard hardwood bar (13 × 25 × 150 mm) or stainless tamping rod to purge trapped air pockets.
- Mold Removal: Clean excess paste from around the base and smoothly lift the brass cone vertically, leaving a freestanding conical specimen.
- Manual Energy Input: Rotate the heavy-duty hand wheel to complete 25 drops in 15 seconds for ASTM C230, or 15 drops for EN 1015-3, causing the platform to drop freely through the calibrated vertical distance.
- Spread Measurement: Use a caliper ruler to record the spread diameter across four scribed lines on the table surface, calculating the arithmetic mean to report final percentage flow.
Dynamic Drop Method vs. Static Slump Method
| Method Attribute | Qualitest Manual Flow Table | Standard Slump Cone |
|---|
| Energy Source | Calibrated manual drops (12.7 mm drop distance) | Material self-weight collapse |
| Target Materials | Fresh cement mortar, lime, hydraulic binders | Coarse aggregate concrete mixtures |
| Parameters Captured | Yield stress, plastic viscosity, aggregate separation | Basic settlement height |
| Fiber-Packed Mortars | Overcomes fiber interlocking to measure true fluidity | Clogs completely under static conditions |
| Power Requirement | 100% manual hand-crank operation with zero power required | Manual lift |
