Low heat cement is a type of cement that is designed to generate minimal heat during its setting process. This is achieved through modifications made to the chemical composition of traditional Portland cement.
The unique composition of low heat cement results in a range of desirable properties and characteristics. For example, it is typically more durable and resistant to certain types of environmental stressors, such as sulfate attacks. Additionally, it tends to have a longer setting time than standard cement, which can be advantageous in certain construction applications.
There are a variety of potential uses for low heat cement, including in large-scale infrastructure projects such as dams, bridges, and tunnels. It can also be used in buildings and other structures where minimizing the risk of cracking or other forms of damage is a top priority.
Overall, low heat cement offers a number of advantages over traditional Portland cement. In addition to its unique properties and characteristics, it can help to reduce the risk of thermal cracking and other forms of damage that can occur during the setting process. This makes it an attractive option for a wide range of construction applications.
Fig 1: Construction of Dam using Low Heat Cement.
Composition of Low Heat Cement
There is a special type of cement that is similar to the commonly used Portland cement, but with slight variations in its chemical makeup. Specifically, this type of cement has a lower percentage of tricalcium aluminate (C3A) at 5%, and a higher percentage of dicalcium silicate (C2S) at 46%.
Properties of Low Heat Cement
Table 1: Properties of Low heat Cement
| Item | Standard Value |
| Specific Surface Area | 250 m2/kg Min |
| Initial Setting | 60 minutes Min |
| Final Setting | 12 hours Max |
| Compressive Strength at 7d | 13.0 MPa Min |
| Compressive Strength at 28d | 42.5 MPa Min |
| Breaking Strength at 7d | 3.5 MPa Min |
| Breaking Strength at 28d | 6.5 MPa Min |
| Heat of Hydration at 3d | 230 KJ/kg Max |
| Heat of Hydration at 7d | 260 KJ/kg Max |
Characteristics of Low Heat Cement
Low heat of hydration is a characteristic that sets it apart from OPC cement, as it is 20% lesser in comparison. This means that less heat is generated during the process of hydration, which is beneficial in preventing thermal cracking of concrete structures. Additionally, this type of cement requires less water for hydration, resulting in better workability and a more fluid consistency of the concrete.
Moreover, this type of cement is known for its good volume stabilisation, which helps in maintaining the integrity and durability of concrete structures over time. Although its initial strength may be low, it exhibits a high growth rate of final strength, making it a preferred choice in construction projects that require high technical strength of concrete.
In terms of resistance to wear and erosion, this type of cement performs exceptionally well, providing excellent impact erosion and wear resistance. It also has a lower temperature upward value of heat insulation, making it a suitable choice for structures that require heat insulation properties. Furthermore, it exhibits super-high performance of chemical corrosion resistance, making it a preferred choice for structures that are exposed to chemical substances.
In terms of its resistance to drying shrinkage and rupture, this type of cement performs well, making it a reliable choice for construction projects that require good resistance to these types of stresses. Overall, the unique properties of this type of cement make it a valuable addition to the construction industry, offering enhanced performance and durability to concrete structures.
Compatibility for Admixtures
Low Heat Cement is a type of cement that is widely used in construction projects where the heat generated during the curing process needs to be controlled. It is a special type of Portland cement that contains lower amounts of tricalcium aluminate (C3A) and dicalcium silicate (C2S) which helps in reducing the heat generation during the setting and hardening of the cement.
One of the benefits of using Low Heat Cement is that it is compatible with different types of chemical admixtures for concrete. These admixtures are commonly used to enhance the properties of concrete and improve its performance in different environmental conditions. They can be used to modify the setting time, workability, strength, and durability of concrete.
Low Heat Cement is also compatible with different types of supplementary cementitious materials that are commonly used in construction projects. These materials include fly ash, slag – ground granulated iron blast-furnace, and amorphous silica. When used in combination with Low Heat Cement, these materials can improve the strength, durability, and resistance to chemical attack of concrete.
In summary, Low Heat Cement is a versatile building material that is compatible with a wide range of chemical admixtures and supplementary cementitious materials. This makes it an ideal choice for construction projects that require controlled heat generation during the curing process and enhanced properties of concrete.
Uses of Low Heat Cement
The surface of factories, particularly chemical plants and sulphuric acid factories, requires a specific type of road and workroom construction to withstand the harsh conditions of the environment. These areas need to be resistant to chemical damage, corrosion, and other potentially hazardous elements that may be present.
Moreover, there are specific construction requirements for projects such as building dams, large footings, large raft slabs, and wind turbine plinths. These structures need to be sturdy and durable to provide long-lasting support and withstand harsh weather conditions.
To achieve these objectives, special construction materials are used, including concrete mixes with high-strength characteristics, chemical-resistant coatings, and advanced reinforcement systems. These materials and techniques are designed to create robust, long-lasting surfaces capable of withstanding the demanding conditions of industrial environments and large construction projects.
Fig 2: Construction of Power Plant using Low heat cement.
Advantages of Low Heat Cement
There are several benefits associated with the use of a certain type of concrete that can help to minimize the potential for thermal cracking in thick concrete sections. This type of concrete also exhibits excellent durability performance and high final strength, making it an ideal choice for a variety of construction projects.
In addition to its strength and durability, this type of concrete is also known for its resistance to sulphate corrosion and good lasting properties. It has good resistance to rupture and anti-seepage properties, making it well-suited for use in hydraulic engineering concrete and marine concrete works where large pours are required.
Another advantage of this type of concrete is its increased workability and pumpability, which can be particularly useful for projects that require large pours or complex shapes. Additionally, this type of concrete has been shown to exhibit significantly improved later-age concrete strengths, which can help to ensure the long-term durability of a structure.
Finally, this type of concrete has been found to be highly resistant to sulphate attack on reinforcement, particularly in the case of concrete pipes. This makes it an excellent choice for projects that require corrosion-resistant materials or that are located in environments with high levels of sulphate exposure.
Disadvantages of Low Heat Cement
A new type of cement has been developed that has a lower initial strength than Ordinary Portland Cement (OPC), but its final strength is equivalent to that of OPC. However, it is not suitable for use in cold weather conditions. Despite its desirable properties, this cement is more expensive than OPC, making it a less attractive option for some applications.