Cement is the hydraulic cement having the ability to convert cement (cement, sand, aggregate, water) into concrete during wet conditions.
Among all other cements, hydraulic cement is the most common type used primarily for construction.
For concreting compound, cement is added to the mixture, so it does not need to dry to set as it may set in a wet environment.
Here we will learn about Hydraulic Cement, types of Hydraulic Cement, Advantages and Disadvantages of Hydraulic Cement.
Introduction to Hydraulic Cement:
Hydraulic cement is a product that is used to prevent water and leakage in concrete and masonry structures.
It is a type of cement, similar to a mortar that becomes extremely sharp and hard after mixing with water.
Typically, some chemical reactions occur in a mixture of water and dry hydraulic cement.
As a result of this reaction, water containing chemical compounds is formed as it helps to harden the mixture.
Due to these compounds, this concrete is insoluble in water and recommended as an ideal cement for building brick buildings.
Types of Hydraulic cement:
Type GU: General Use.
Type HE: High Early Strength.
Type MS: Moderate Sulfate Resistance.
Type HS: High Sulfate Resistance.
Type MH: Moderate Heat of Hydration.
Type LH: Low Heat of Hydration.
2. Portland cement:
Type I, Type IA: general purpose cements.
Type II, Type IIA: contain no more than 8% tricalcium aluminate.
Type III, Type IIIA: similar to Type I but has higher early strength.
Type IV: develops strength over longer periods of time, used in special type of structures that require heat to be generated from hydration.
Type V: high sulphate resistance, contains no more than 5% tricalcium aluminate.
3. Blended cement:
Type IS (X): Portland blast furnace slag cement.
Type IP (X): Portrland-pozzolan cement.
How to Apply Hydraulic Cement:
Hydraulic cement must be applied to surfaces that have cleaned, oil, dust & grease-free or any other contaminant that may have an effect on the relationship with the permanent structure.
These are the steps for a successful application:
- Be sure to remove all loose particles before applying to the surface.
- It is recommended to reduce all areas to which this concrete will be applied.
- The ACI recommends that the area to be labored should be saturated for 24 hours before this concrete is utilized.
- It is important to preserve an area temperature between 45 ° F (7 ° C) and 90 ° F (32 ° C) in the course of the preliminary remedy.
- Preparation should include enlarging small cracks, holes and avoiding V-shaped cuts.
- Hydraulic cement shall be mixed using a mechanical mixer with rotating blades to form a uniform mixture.
- The pre-weight mixer removes excess water from it.
- Add water following manufacturer’s recommendation and then add the dry hydraulic cement mix. Do not add water once it begins to set.
- Blend at a relatively low speed and be sure to mix only a small amount of cement that can be kept in the working hours.
- Start applying this concrete to the top of the crack so your way down.
- Press the paste firmly, maintaining pressure until the cement hardens and the leak stops.
- Do not mix excess water as this will cause bleeding and isolation.
- Do not use any other admissions or additives.
Advantages of Hydraulic cement:
- It provides durable repair that will last longer.
- This cement usually sets rapidly and hardens, usually three minutes after being mixed with water.
- It is a cost effective solution.
- Hydraulic cements is very easy to use.
- Hot water will speed up the setting time and cold water will dim it.
- It can be used on vertical applications.
- It will maintain its strength even when submerged in water.
- Besides, it will not corrode nor rust.
- Hydraulic cements will not shrink.
- It may repair the leaky pipes and basements without stopping leaks.
- It may be painted within an hour of utility.
Disadvantages of Hydraulic cement:
- As soon as mixed, hydraulic cements stays workable for less than 10 to 15 minutes.
- It will not work on frozen surfaces or if the temperature drops dramatically within 48 hours
- Avoid using it when the temperature is below 40 degrees.
Application of Hydraulic Cement:
Hydraulic cements can be used above or under grade, however, this can be very useful if used in:
- Swimming pools.
- Drainage systems.
- Elevator pits.
- Basement walls.
- Sealing around concrete and masonry structures.
- Marine applications.
- Cisterns and fountains.
Hydraulic cements hardens when exposed to water.
This type of cement is commonly used to make concrete that is used in the construction of buildings and is also usually waterproof.