Ready-mix mortar is a building material designed for use in construction projects. It is made by mixing cement, sand and water in varying proportions, depending on the desired strength and consistency of the finished product. In addition to these basic ingredients, ready-mix mortar also contains a range of chemical additives designed to improve its performance and durability.
Chemical additives are substances added to a material to enhance or change its properties. For ready-mixed mortars, these additives are often chosen for their ability to improve workability, shorten setting time, increase water retention, and enhance the strength and durability of the finished product.
In this article we will look at some of the key chemical additives commonly used in ready-mix mortar manufacturing.
1.Retarder
Retarders are a class of chemical additives used to slow down the setting time of cement-based materials. They work by delaying the chemical reaction that occurs when cement comes into contact with water, giving workers more time to complete the work before the mortar sets.
Retarders are particularly useful in hot weather conditions or when working with large quantities of mortar, which might otherwise set too quickly. They are usually added to the mortar mixture at a rate of 0.1% to 0.5% of the cement content.
2. Plasticizer
Plasticizers are another type of chemical additive commonly used in ready-mixed mortars. Their purpose is to reduce the viscosity of the mortar, making it easier to handle and use.
Plasticizers are usually added to the mortar mixture at a rate of 0.1% to 0.5% of the cement content. They improve the flow characteristics of the mortar, making it easier to spread and achieve a uniform surface finish.
3. Water retaining agent
Water-retaining agent is a type of chemical additive that improves the water-retaining performance of mortar. Their purpose is to reduce the amount of water lost by evaporation during the curing process, which helps prevent shrinkage and cracking.
Water retaining agents are usually added to the mortar mixture at a rate of 0.1% to 0.2% of the cement content. They improve the workability of the mortar, making it easier to apply and achieve a smooth, even surface.
4. Air-entraining agent
Air-entraining agents are used to introduce tiny air bubbles into the mortar mixture. These bubbles act as tiny shock absorbers, increasing the durability and freeze-thaw resistance of the finished product.
Air-entraining agents are typically added to the mortar mixture at a rate of 0.01% to 0.5% of the cement content. They can improve the workability of the mortar and make it easier to apply, especially when working with difficult aggregates.
5. Accelerator
Accelerators are chemical additives used to speed up the setting time of mortar. They are typically used in cold weather conditions or when mortar needs to be completed quickly.
Accelerators are usually added to the mortar mixture at a rate of 0.1% to 0.5% of the cement content. They can help reduce the time it takes for mortar to cure and reach full strength, which is important on time-sensitive construction projects.
6. High-efficiency water-reducing agent
Superplasticizer is a plasticizer used to enhance the workability of mortar. They work by dispersing cement particles more evenly throughout the mortar mixture, thereby improving its flow characteristics.
Superplasticizers are usually added to the mortar mixture at a rate of 0.1% to 0.5% of the cement content. They improve the workability of the mortar, making it easier to apply and achieve a smooth, even surface.
Ready-mix mortar is a popular building material that is widely used in a variety of construction projects. It consists of a mixture of cement, sand and water, as well as a range of chemical additives used to improve its performance and durability.
Some of the key chemical additives used in ready-mixed mortar include retarders, plasticizers, water retaining agents, air entraining agents, accelerators and superplasticizers. These additives are carefully selected to improve processability, shorten setting time, increase water retention and enhance the strength and durability of the finished product.
By understanding the role of each chemical additive, construction professionals can select the correct type of ready-mix mortar for their specific project and ensure it meets its performance and durability requirements.
Post time: Sep-26-2023