The most common strength test, compressive strength, is carried out on a 50 mm (2-inch) cement mortar test specimen. The test specimen is subjected to a compressive load (usually from a hydraulic machine) until failure. This loading sequence must take no less than 20 seconds and no more than 80 seconds. Table 2 shows ASTM C 150 compressive strength specifications.
Table 2. ASTM C 150 Portland Cement Mortar Compressive Strength Specifications in MPa (psi)
Curing Time | Portland Cement Type | |||||||
I | IA | II | IIA | III | IIIA | IV | V | |
1 day | - | - | - | - | 12.4 (1800) |
10.0 (1450) |
- | - |
3 days | 12.4 (1800) |
10.0 (1450) |
10.3 (1500) |
8.3 (1200) |
24.1 (3500) |
19.3 (2800) |
- | 8.3 (1200) |
7 days | 19.3 (2800) |
15.5 (2250) |
17.2 (2500) |
13.8 (2000) |
- | - | 6.9 (1000) |
15.2 (2200) |
28 days | - | - | - | - | - | - | 17.2 (2500) |
20.7 (3000) |
Note: Type II and IIA requirements can be lowered if either an optional heat of hydration or chemical limit on the sum of C3S and C3A is specified |
Standard Test Methods
- AASHTO T 106 and ASTM C 109: Compressive Strength of Hydraulic Cement Mortars (Using 50-mm or 2-in. Cube Specimens)
- ASTM C 349: Compressive Strength of Hydraulic Cement Mortars (Using Portions of Prisms Broken in Flexure)