Ordinary portland cement(OPC) is usually made from a combination of limestone, clay, silica, and iron oxide. Clinker, new mineral, is produced by burning mixture of crushed material at high temperature kilns. And cement is produced by mixing gypsum, setting time retarder, and grinding it. Various types of cement are produced depending on the mineral composition, and Ordinary portland cement is the most commonly used product. It can be used at most construction sites, and is economical compared to other construction materials.
It is the most commonly used cement, divided into five types according to the purpose and usage.
Used in building structures, civil engineering structures, secondary products including Pre Cast, raw materials of blended cement and specialty cement.
| Chemical Components |
Standard | Normal (Type 1) |
Moderate heat (Type 2) |
High early-strength (Type 3) |
Low-heat (Type 4) |
Sulfate resisting (Type 5) |
|---|---|---|---|---|---|---|
| Magnesium oxide (MgO) | Below 5.0 | Below 5.0 | Below 5.0 | Below 5.0 | Below 5.0 | |
| Sulfur trioxide (SO) | Below 3.5 | Below 3.0 | Below 4.5 | Below 3.5 | Below 3.0 | |
| Loss of Ignition (%) | Below 5.0 | Below 5.0 | Below 5.0 | Below 5.0 | Below 5.0 | |
| C3S (%) | Below 50 | |||||
| C2S (%) | Below 40 | |||||
| C3A (%) | Below 80 | Below 60 | Below 40 |
| Physical Performance |
Standard | Normal (Type 1) |
Moderate heat (Type 2) |
High early-strength (Type 3) |
Low-heat (Type 4) |
Sulfate resisting (Type 5) |
||
|---|---|---|---|---|---|---|---|---|
| Fineness (cm2/g) | Over 2800 | Over 2800 | Over 3300 | Over 2800 | Over 2800 | |||
| Soundness | Autoclave Expansion (%) | Below 0.8 | Below 0.8 | Below 0.8 | Below 0.8 | Below 0.8 | ||
| Setting time |
Vicat test |
Initial set (Min.) | Over 60 | Over 60 | Over 45 | Over 60 | Over 60 | |
| Termination (Hour) | Below 10 | Below 10 | Below 10 | Below 10 | Below 10 | |||
| Hydration heat (J/g) | 7 Days | Below 290 | Below 250 | |||||
| 28 Days | Below 340 | Below 290 | ||||||
| Compressive strength MPa (N/mm2) |
1 Days | Over 10.0 | ||||||
| 3 Days | Over 12.5 | Over 7.5 | Over 20.0 | Over 10.0 | ||||
| 7 Days | Over 22.5 | Over 15.0 | Over 32.5 | Over 7.5 | Over 20.0 | |||
| 28 Days | Over 42.5 | Over 32.5 | Over 47.5 | Over 22.5 | Over 40.0 | |||
| 91 Days | Over 42.5 | |||||||
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