Hydraulic cement, (also well-known as Portland cement), sets and bonds with other materials when a chemical reaction occurs between the dry ingredients and water. This allows setting in wet conditions, or even under water, as the cementitious mixture is impermeable to water.
It is also a quick-set cement useful for lower grade structures that need sealing, or are in constant contact with water. Calcium silicates are one component of hydraulic cement and result in a product that is non-corrosive. There are many applications perfect for a product of this makeup and quality.
Non-hydraulic cement is the ‘normal’ type of cement which we are all familiar with and does not set in wet conditions or under water. Rather, it sets as it dries by reacting with carbon dioxide in the air and is also resistant to attack by chemicals after setting.
The history of hydraulic cement
The concept of quick set ‘cement’ goes far back to Roman times, but the ingredients were slightly different, namely volcanic ash (pozzolana) and lime (calcium oxide). Although this mixture was patented in the 1700’s, a superior product replaced it in the 1800’s.
Today, this style of cement has become very popular worldwide in construction and owing to consistent development, there are now a variety of products available to suit all kinds of applications.
How does hydraulic cement work?
Hydration is key in making cement. As soon as water is added, certain ingredients activate through basic chemical reaction:-
- the product hardens and cures in a much shorter time than a traditional wet mix;
- good strength is supplied to the bond.
Because of the faster setting time, however, engineers only recommend this product for projects that can be completed within a maximum of 15 minutes and in medium batch sizes. In addition, as it is not a flexible product, hydraulic cement is more suitable for mechanical support usage, as opposed to general use, such as flooring.
Cold climates are not suitable for the use of this cement, as specialists’opinion widely advises that for the best results, application should be completed in temperatures higher than 7° Celsius and frozen surfaces avoided altogether.
Hydraulic cement uses
Hydraulic cement is ideal for interior and exterior applications to stop the escape of water through cracks and faults in concrete and masonry structures. Some examples of these include:
- Swimming pools
- Dams
- Fountains
- Foundations
- Sewers
- Road foundations
- Concrete block houses
- Manholes
Advantages and Disadvantages of Applying Hydraulic Cement Mixtures:
Like anything, there are benefits and challenges of using this type of cement.
| Benefits | Challenges |
| Long lasting | Workable time is a maximum of 15 minutes |
| Fast drying and curing times | Cold weather is not suitable for this application |
| Easy to work with | Is not a flexible material |
| Cost effective | |
| Non-corrosive | |
| Suitable for vertical applications | |
| Can be used for waterproofing, as well as for sealing cracks | |
| Does not shrink | |
| Paint can be applied after an hour | |
| Hot water increases setting times and cold water decreases this duration. | |
| Maintains its strength |
Innovation is a fundamental feature of Blend Plants Africa, as the team pays attention to all aspects of the construction industry. They recognise customer challenges and needs, leading to the development of solutions that will beneficially impact such activities. Blend Plants’ goal is to offer equipment that will improve the quality, the efficiency and, particularly, the profitability of all their customers’ projects.
When it comes to cement mixing, Blend Plants’ E-Series mobile plants have one to three aggregators installed, while the A-Series has a maximum of four on their ground units. BLEND Plant Africa’s solutions can cater for a wide choice of applications from hydraulic cement for stabilisation and bridge mixes, to laboratory specified mix, colour cement, backfill or simply standard concrete. Contact Blend Plants for more information on how to plan well in advance with little downtime on site.