Admixtures are special ingredients added to the concrete mix in addition to water, sand, cement, and aggregates to improve its construction properties. Using admixtures in concrete makes it more suitable for a particular project.
Types of Admixtures
The types of admixtures used in concrete:
1. Chemical Admixtures
a) Plasticizers
b) Super Plasticizers
c) Accelerators
d) Set Retarders
2. Mineral Admixtures
a) Cementitious
b) Pozzolanic
c) Ground Granulated Blast Furnace Slag (GGBF)
d) Fly Ash
e) Silica Fume
f)Rice Husk Ash
Factors to Consider When Using Admixtures in Construction
1. Type of Project: Different construction works need different concrete properties, so choose an admixture that fits the needs of your specific project.
2. Properties Required: Consider what enhanced properties you need in your concrete. It could be increased workability, faster setting times, or greater durability against weather conditions.
3. Compatibility with Cement: Make sure the admixture you select is compatible with the type of cement you’ll use, as this greatly affects the outcome of the concrete mixture.
4. Environmental Conditions: The effectiveness of an admixture can be influenced by the temperature and humidity at the construction site. Select the admixture that is most suitable for the weather conditions in your area.
5. Dosage: Ensuring the correct quantity of admixture is crucial for the functionality of the concrete. Admixture used in concrete cannot be over or under-used as it can lead to problems like segregation or inadequate setting times.
Choosing the right admixture in construction can greatly improve the performance and durability of the concrete for your building project, making it a critical decision for home builders.