Good quality concrete starts with the quality of materials, cost effective designs is actually a by-product of selecting the best quality material and good construction practices. Technical knowledge is an advantage for concrete producer, even if the concrete mix design is good but uncommon or wrong procedures are practiced it will result to failures.
Normal concrete is the combination of cement, aggregates (coarse and fine), water, admixture. In which, cement is the most importance factor that influence the characteristics of concrete. Difference types of Portland cement are manufactured to meet various normal physical and chemical requirement for specific purposes. Portland cement are manufactured to meet the specification of ASTM (American Society for Testing and Materials) C150, ASTM 1157, AASHTO (American Association of State Highway and Transportation Officials) M85
Here after are important things to remember on the properties and use of cement
1. About 30 kilograms of water are required to fully hydrate 100 kilograms of cement.
2. Hydration starts as soon as water is introduced to cement.
3. Rule of thumb: the higher water / cement ratio the lower the strength so keep water cement ratio as low as possible.
4. It is a good practice to order cement in advance to cool down its temperature, remember that 5 degrees
increase in cement temperature increases concrete temperature by 0.5 degrees.
5. Normal temperature range of cement before batching should be 66 Celsius degrees to 85 Celsius degrees.
6. Specific gravity range is between 3.10 to 3.25 of Portland cements and blended cement is 2.90 to 3.15.