Hydrophobic cement, also known as hydrographic cement, is produced by grinding portland cement clinker with a substance that forms a film, such as oleic acid. The purpose of adding this substance is to slow down the rate of deterioration that may occur when the cement is stored under unfavorable conditions.
This type of cement is named after its properties, as “hydro” means water and “phobic” means against. It is designed to repel water, making it useful in construction projects that may be exposed to water or moisture.
Hydrophobic cement has various advantages, such as improved durability, reduced water absorption, and increased resistance to chemical attacks. It is commonly used in the construction of bridges, dams, and other structures that are exposed to water.
However, hydrophobic cement also has some disadvantages, such as higher cost compared to regular cement and a longer setting time. It is important to take safety precautions when using hydrophobic cement, as the film-forming substance used in its production can be hazardous if not handled properly.
In summary, hydrophobic cement is a type of cement that repels water and is produced by grinding portland cement clinker with a film-forming substance. It has various advantages and disadvantages, and it is important to take safety precautions when handling it.
Fig 1: Water resistant concrete made of Hydrophobic cement.
Manufacture of Hydrophobic Cement
The manufacturing process for this unique cement is identical to that of Portland cement. The clinkers produced during cement production are ground along with a water-repellent film substance such as Oleic Acid or Stearic Acid. These chemicals form a layer around the cement particles, preventing water from mixing and initiating the hydration process during transportation or storage. However, during the mixing process, this layer of water repellent is disrupted due to intense agitation, which permits the hydration process to occur.
Properties of Hydrophobic Cement
Table 1: Properties and their values of Hydrophobic cement.
| Properties | Value |
| Fineness | 350 m2/kg |
| Soundness | |
| Lechatelier (mm) | 10mm |
| Autoclave | 0.8 % |
| Setting Time | |
| Initial Setting | 30min |
| Final Setting | 600min |
| Compressive Strength | |
| 3days | 16 MPa |
| 7days | 22 MPa |
| 28days | 30 MPa |
| Water Absorption | 0.3 – 1 % |
Uses of Hydrophobic Cement
Cements that are suitable for longer storage periods and extremely wet climatic conditions are widely used in the construction industry. These types of cements are particularly beneficial for tunnel construction, as underground repairs can be challenging and expensive. Additionally, they are often utilized in the construction of dams, spillways, and other underwater structures.
Another important application of these cements is in structures that are exposed to rain or rain puddling. This includes green roofs, various types of roofs, parking structures, and plazas. Their ability to withstand water and moisture makes them ideal for these kinds of projects.
Furthermore, these cements are commonly used in drainage systems and manholes. Their ability to resist water and moisture makes them ideal for these applications, where water is constantly present.
In addition, these cements are also used in the construction of water treatment plants, dams, and retaining walls. Their durability and resistance to water make them an ideal choice for these applications.
Finally, these types of cements can be used to fix leaky pipes and basements without having to stop the leaking. This makes them an excellent choice for repairing and maintaining buildings and structures that are susceptible to water damage.
Advantages of Hydrophobic Cement
Hydrophobic cement offers several significant advantages over ordinary cement. One of the key benefits is that it provides durable repairs that can last for extended periods of time. This is because hydrophobic cement is specifically designed to repel water and other forms of moisture, which can cause ordinary cement to deteriorate over time. As a result, structures built with hydrophobic cement are less susceptible to damage from water-related issues such as erosion, freeze-thaw cycles, and chemical attacks.
Another advantage of hydrophobic cement is that it possesses the same strength as ordinary cement. This means that it can be used in a wide variety of construction projects without compromising on the structural integrity of the final product. In addition, hydrophobic cement sets and hardens quickly, typically within three minutes of being mixed with water. This rapid setting time makes it ideal for projects that require a quick turnaround, such as repairs or emergency construction work.
One of the most notable benefits of hydrophobic cement is its fast setting time, which allows it to harden quickly. This means that it can be painted within an hour of being applied, making it a popular choice for construction projects that require a rapid finish. Furthermore, the fast setting time of hydrophobic cement reduces the amount of time required for construction projects, which can lead to cost savings and increased productivity. Overall, the advantages of hydrophobic cement make it an excellent choice for a wide range of construction projects.
Disadvantages of Hydrophobic Cement
Hydrophobic cement, while useful in preventing leaks, does have some drawbacks that must be considered. For one, it is not effective on frozen surfaces and cannot be used when temperatures drop below 40 degrees Fahrenheit. Additionally, while it can help with leaking, it does not address issues that arise from condensation.
Another potential challenge is that hydrophobic cement requires skilled labor and favorable weather conditions for application. This can limit its practical use and may make it more difficult to implement in certain situations.
Finally, the cost of hydrophobic cement can be a barrier for some. Due to its effectiveness and specialized properties, it is often more expensive than traditional cement options. This cost can make it inaccessible for some projects or individuals who may be operating under budget constraints.
Health and Safety Precautions of Hydrophobic Cement
When working with materials that produce dust, it is important to take precautions to protect yourself. One of the most important precautions is to avoid breathing in the dust. Inhaling dust particles can lead to serious health problems, especially if the dust contains silica. Even brief exposure to silica dust can cause lung damage over time.
It is also important to avoid any contact with the dust, especially with your eyes or skin. If the dust comes into contact with your skin, it can cause irritation and other issues. Similarly, if the dust gets into your eyes, it can cause redness, irritation, and even damage to your vision.
While there is no real evidence that silica is a carcinogen, it is still important to take precautions when working with materials that contain silica dust. To protect yourself, it is recommended that you use protective clothing such as gloves or a mask. This can help to prevent the dust from getting onto your skin or into your respiratory system, reducing the risk of health problems caused by exposure to silica dust.