Pressure Cells
Style Shotcrete Stress
The Model 4850 NATM Style Shotcrete Stress Cells* are designed for the measurement of tangential (4850-1) and radial (4850-2) stresses in shotcrete tunnel linings. The cells consist of two rectangular steel plates welded together around the periphery with a de-aired fluid occupying the space between the plates. A short tube connects the cell to a vibrating wire pressure transducer. A prestressing tube is provided for expanding the cell after the concrete has cured. Cells of this type are also used for measurements of stress in mass concrete.
| Specifications | |
|---|---|
| Standard Ranges¹ | 4850-1 | 7.5, 20, 35 MPa
4850-2 | 2, 3, 5 MPa |
| Over Range | 150% F.S. |
| Resolution | 0.025% F.S. |
| Accuracy² | ±0.1% F.S. |
| Temperature Range¹ | −20°C to +80°C |
| L × W × H¹ | 4850-1 | 200 × 100 × 6 mm
4850-2 | 250 × 150 × 6 mm |
¹Other ranges and sizes available on request.
²Transducer accuracy established under laboratory conditions.
Total system accuracy (pressure transducer + pressure cell) is subject to site-specific variables.