Properties and uses of white cement concrete
White cement concrete has similarity with grey Portland cement but the main difference lies in fineness and color. The white color of this cement is obtained by its manufacture system and its raw materials. There are wide array of color options in this type of cement for developing architectural and structural concrete.
This cement is formed with raw materials with little or no iron or manganese. Normally, china clay is utilized in white cement along with with limestone or chalk.
The cement should be white Portland cement with adherence to the standard specification ASTM C150.
The compressive strength of white cement is less as compared to OPC cement.
A large amount of iron and manganese are added in its manufacturing process to enhance the whiteness of the cement and becomes more expansive. White cement concrete is called as snow Crete. With white cement, a homogenous concrete is produced with exact color for a structure.
To develop white cement, 40% higher energy is necessary as compared to the normal grey cement and it makes the white cement expensive. Light colored sand along with whitest chalk is provided in the production of white cement.
HOW TO CHOOSE PROPER RAW INGREDIENTS:
Cement: The delivery of white cement in both bulks and bagged. The storage of the white cement bagged should not get in touch with the ground. If storing is made in the concrete floor then the cement should be stored up against the exterior walls. White cement bags should be preserved in pallets and it should be safeguarded from weather and maintain them off the ground. Due to the low content of soluble chromium, white cement should be preserved for minimum of 6 months when provided in proper dry condition.
Aggregates: The selection of aggregates for white should comprise of the white marble, white granite, and crushed calcinated flint. The color choice of coarse aggregates is crucial to the final appearance of white concrete. The selection of fine aggregates especially the filler particles should be lower than 0.25mm. Precautions should be taken to make sure that the mix of aggregates remain as constant as possible among batches to avoid in shading of finished products.
Water: Water to be mixed in white concrete should be clean and does not contain organic impurities. The water-cement ratio remains high in white concrete with regards to normal concrete and is critical in finding out the final strength of concrete.
CHARACTERISTICS OF WHITE CEMENT CONCRETE:
1. The initial setting time of white cement should 100 minutes.
2. The fineness of white cement should be 395 kg/m2.
3. The brightness of white cement should remain 87%.
4. The compact density of white density should be 3150 kg/m3.
5. Bulk density of white cement is 110 kg/3.
6. Compressive strength after 1 day 21 Mpa, after 2 days 38 Mpa, 7days 61 Mpa and after 28 days 74 Mpa.
APPLICATIONS OF WHITE CEMENT:
1. White cement is effective for decorative works as well as prestige construction projects.
2. White cement is applied to develop brightly colored concrete and mortars.
3. It is suitable for interior and exterior decoration due to its whiteness.
4. White cement is frequently applied in roads to enhance the visibleness to highway medians.
5. It is useful for huge numbers of manufacturing precast members.