Question 8.1: Given a 4 in. × 4.6 in. compacted soil specimen prepared fro...
Given a 4 in. × 4.6 in. compacted soil specimen prepared from standard AASHTO compaction procedure.
Determining the tensile strength by use of the UP test
From Equation (8.2) where
Diameter of soil specimen = 4 in.; height of specimen, H = 4.6 in.
b= 4/2 = 2 in. (Fig. 8.10), a = diameter of punch = 0.5 in.
K = constant depend on specimen size = 1.2 (Table 8.2)
P = maximum load obtained from test at failure condition = 200 lb then
\sigma _{t}=\frac{P}{\pi \left(KbH- a^{2} \right) } (8.2)
\sigma _{t} =P/\pi \left(KbH- a^{2} \right) =200/3.1416 \left[1.2\times 2\times 4.6- \left(0.5\right) ^{2} \right]
=5.9 psi = 40.6 kN/m^{2}
| Table 8.2 Recommended values for parameter, K, specimen-punch size, specimen height–diameter ratio, and rate of loading | ||
| Specimen size | K value | |
| Soil | Stabilized materials | |
| Proctor mold | 1.0 | 1.2 |
| 4 in. \times 4.6 in. (10.2 cm \times11.43 cm) | ||
| CBR hold | 0.8 | 1.0 |
| 6 in. \times7 in. (15.24 cm \times 17.78 cm) |
|
|
| Larger than 12 in. (0.305 cm) | 0.8 | |
| Specimen-punch size: | 0.2–0.3 | |
| Height to diameter ratio of | 0.8–1.2 | |
| specimen: |
|
|
| Rate of loading:
|
ASTM recommendation for the axial strain at a ratio of 0.5–2% of height per minute |
|
