Portland pozzolana cement is the type of cement which is a blend of different types of material like gypsum and pozzolana etc. This type of cement is especially useful in general construction work as well as is suitable for applications in aggressive environmental conditions.
Portland pozzolana cement is mostly used in the construction of hydraulic structures, marine works, mass concreting such as dams, dykes, retaining walls foundations and sewage pipes.
There are two types of pozzolana that are utilised in the making of Portland pozzolana cement.
- Fly ash
- Calcined clay
Now let us understand what are the uses of Portland pozzolana cement.
Uses Of Portland Pozzolana Cement
The following are the uses of Portland pozzolana cement.
Portland pozzolana cement provides an increased amount of workability, has less segregation and bleeding. It also has an increased amount of water tightness and reduction in the tendency of lime to leach out. Less heat of hydration is produced and a great amount of resistance to the attack of water containing sulphates and chlorides is offered. This causes an improvement in the durability of the structures and also improves the strength of concrete over a period of time. This is done by making the concrete more corrosion resistant and impermeable.
Now, we will see the Portland pozzolana cement properties
Properties Of Pozzolana Cement
- Initial setting time is half an hour or 30 minutes
- Final setting time is 600 minutes or approximately 10 hours.
- Dry shrinkage should be maximum 0.15 percent.
- The rate of strength development of Portland pozzolana cement is comparatively less than ordinary Portland cement.
Now, let us understand the advantages and disadvantages of Portland pozzolana cement.
Advantages And Disadvantages Of Portland Pozzolana Cement
Advantages:
1. Calcium hydroxide, in case of Portland pozzolana cement, which is originally a soluble compound, can be converted into an insoluble segment of cement.
2. Because Portland pozzolana cement helps in the prevention of entry of moisture, it is mostly used in the marine works.
3. The heat of hydration generated by Portland pozzolana cement is comparatively lesser than the heat of hydration given out by ordinary Portland cement.
4. This cement is considered to be extremely cost efficient due to its replacement of ordinary Portland cement with puzzolonic products.
Disadvantages
1. Earlier de shuttering of formwork may turn out to be dangerous as more time is taken by it that ordinary Portland cement, in order to garden.
2. To set and mature, it takes longer than ever in comparison to other cements.
