C-ADD: What are cement additives?

Cement additives are chemical substances added during the cement manufacturing process to improve its properties and optimize the production process. The MAPEI Cement Additives Division (C-ADD) delivers innovative technologies and advanced, sustainable solutions for cement manufacturing.

Benefits of Cement Additives

• Optimize cement properties and production process
• Improve powder flowability, strength development, and durability
• Allow adjustment of cement quality to meet industry standards and specific customer needs
• Increase profitability of cement plants
• Reduce environmental impact with reduced energy and resource demand
  

How They Work

Cement additives are added during the manufacturing process, typically when raw materials are heated to around 2,732°F (1 500°C) to achieve final chemical properties. They interact with cement particles to modify surface properties and chemical reactions during hydration.

Comparison to Concrete Admixtures

It's important to note that cement additives differ from concrete admixtures:

• Cement additives are added during cement manufacturing
• Concrete admixtures are added when mixing concrete (which contains cement as an ingredient)

Four Types of MAPEI Cement Additives

MCH C-C: Strengths and Flow Enhancers from Cement to Concrete

MCH C-C are polycarboxylate based products used to improve cement quality in terms of workability and strength, and to aid cement grinding by increasing mill production.

Characteristics: MCH C-C are highly concentrated additives formulated with only selected raw materials, to guarantee absolute constancy of quality and superior performance. Thanks to their formulation rich in acrylic polymers, MCH C-C notably improve the cement workability and reduce the water demand, especially in blended cements.

Moreover, thanks to their formulation, they increase the cement strength because of the improved granulometric distribution, the higher fineness, and the higher calcium silicates hydration rate of the finished product.

Application: Use MCH C-C in case you would like to improve the performance of new cements (i.e., calcined clay, demolition waste, recycled concrete, bricks, tiles) where a significant increase of workability is required.

Moreover, the use of MCH C-C allows to increase mill output and reduce the specific energy consumption significantly, to improve late strengths of cement and reduce the clinker content without affecting cement quality.

MCH: Grinding aids and pack-set inhibitors

MCH additives are high-performance grinding aids generally used to increase mill production and to improve the cement quality.

They are highly concentrated additives formulated with only selected raw materials, to guarantee absolute constancy of quality and superior performance.

Characteristics: Thanks to their polar nature, MCH additives notably reduce the attraction forces of cement particles, the main cause of agglomeration inside tubular mills. They are also able to modify the hydrated structure of cement, thereby improving strengths.

The elimination or drastic reduction of agglomeration improves the granulometric distribution of the finished cement for better cement strength and enhanced efficiency in the separation process.

This allows for maximized production, power savings, and improvements of the specific surface of the finished cement.

Customized formulations of MCH additives allow for the modification of the hydration produced by the cement, thereby increasing the early and/or ultimate strengths.

Applications: MCH additives may be successfully utilized in all cases of pack-set phenomena (when not resulting from humidity) inside the mills, particularly in the grinding of Portland and limestone cements.

Production increases due to usage of MCH additives generally vary between 10% and 30%, depending on the cement fineness, the grinding system available, the clinker’s mineralogical composition, the additive dosage and other factors.

The low pack-set index obtained with MCH additives gives a better flowability of the dry cement powder with faster loading and unloading of trucks, railcars and barges. Cement additives play a crucial role in modern cement production, allowing manufacturers to optimize their processes and produce cements with enhanced performance characteristics tailored to specific applications and environmental conditions.

BXR: Grinding aids and strength enhancers

BXR additives are highly concentrated grinding aids formulated with select raw materials to guarantee consistent high quality and superior performance.

These additives are formulated to improve cement quality (early and/or ultimate strengths) and to aid cement grinding by increasing mill production.

Characteristics: In addition to the advantages through their use as grinding aids, BXR additives guarantee remarkable increases in early and ultimate strength.

BXR additives can increase strength mechanically by providing a better granulometric distribution of the finished cement as well as a higher cement fineness. In addition, these additives can increase strength chemically by promoting a higher hydration rate of calcium silicates.

Applications: BXR additives may be successfully utilized in the grinding of blended cements (with such materials as blast-furnace slag, fly ash, pozzolans and limestone) and in all cases where a significant increase in strength is needed. BXR additives are generally formulated to satisfy the goals of the cement factory.

One option for their use is increase early and ultimate strengths to improve the binder quality. Alternatively, by keeping the cement quality unaltered, it is possible to reduce as much as 4% to 6% of clinker with other components. Under normal conditions, the strength is increased 20% to 50% after one day, and an additional 5% to 15% after 28 days. A third option for use of BXR additives is to reduce the cement fineness while keeping the same cement strength and gaining mill output.

HSG: Grinding aids for Portland cements

HSG additives are high-performance grinding aids generally used to increase mill production and to improve the cement quality. These highly concentrated additives are formulated with select raw materials to guarantee consistent high quality and superior performance.

Characteristics: Thanks to their polar nature, HSG additives notably reduce the attraction forces of cement particles, the main cause of agglomeration inside tubular mills. These additives are also able to modify the hydrated structure of cement, thereby improving strength.

The elimination or drastic reduction of agglomeration improves the granulometric distribution of the finished cement for better cement strength and enhanced efficiency in the separation process. This allows for maximized production, power savings, and improvements of the specific surface of the finished cement.

Customized formulations of HSG additives allow for the modification of the hydration produced by the cement, thereby increasing the early and/or ultimate strengths.

Applications: HSG additives may be successfully utilized in all cases of pack-set phenomena (when not resulting from humidity) inside the mills, particularly in the grinding of Portland and limestone cements.

Production increases due to usage of HSG additives generally vary between 10% and 30%, depending on the cement fineness, the grinding system available, the clinker’s mineralogical composition, the additive dosage and other factors. The low pack-set index obtained with HSG additives gives a better flowability of the dry cement powder with faster loading and unloading of trucks, railcars and barges.

MAPEI provides full-service solutions to the Cement Industry, assisting customers in the production of innovative products and optimizing the cement production process with the aim of achieving carbon neutrality. Our viewpoint is that the combination of Cement Additives and world class Technical Services is the solution that ensures long-term, superior results. The C-ADD Technical Services covers three main areas:

1. Laboratory cement reproduction and testing
2. Industrial mill audits and plant assessments
3. Analytical technical services

Cutting-edge technology is the only way of supporting the cement industry on the roadmap to zero emissions. The MAPEI commitment is to give the highest priority to Sustainability: Environmental, Social and Economical. The Cement Additives Division designs its products in cooperation with the Cement Industry, in order to ensure long term Sustainability and Environmental compatibility.