Strengthens Concrete Increases Hardness

Densification

Concrete densifiers are concrete hardeners that once applied penetrate into the concrete and cause a chemical reaction. During this chemical reaction a concrete densifier reacts with free lime and calcium found naturally occurring in concrete. Calcium silicate hydrate (CSH) is formed by this reaction and fills in the small pores and capillaries of the concrete. This process increases the strength of the concrete making it up to 50% stronger and more durable.

What is concrete made of

At its most basic level, it is a composite material created from a mixture of aggregate (crushed stone and sand), Portland cement, and water. While many may think of concrete and cement as interchangeable terms, they are, in fact, different materials altogether - cement is merely one of the ingredients used to make concrete.

Can concrete be made stronger

Although concrete appears strong, every substrate is different based upon many factors including the water/cement ratio, the coarse/fine aggregate ratio, temperature and curing of concrete. The quality of concrete is judged largely on the strength of the concrete. Concrete’s compressive strength is measured in PSI -pounds per square inch. PSI can range anywhere from 2500 psi to 20,000 psi depending on what is specified. While concrete is a notably hard and durable material, you can take steps to improve the material and extend its lifespan. One of the most common methods of doing this is by using a concrete densifier.

What is a densifier

Concrete densifiers are products that help increase the density of concrete slabs. While the name is obvious, a densifier is substance applied to the surface of concrete in order to fill pores and increase surface density. They are chemical solutions designed to improve surface hardness and density. They react with free lime and calcium hydroxide present in the concrete. This solidifies it, making the concrete surface much less permeable and more resistant to stains.

Concrete densifiers are of a silicate chemistry - of either a lithium, sodium or potassium carrier. Densifiers are classified into two generations. Potassium and sodium silicate are first-generation products and react with the calcium hydroxide in the concrete. The reaction starts immediately but continues slowly, due to the natural closeness of the pH of concrete. This application process is more caustic and labor-intensive. Sodium silicates have been around for over a century and were the first original densifiers.

Second-generation densifiers are lithium silicate-based densifiers. The suspension of the silicate particles allows the solution to penetrate much deeper before this reaction takes place. Lithium silicates are also excellent densifiers, of a newer technology that create an even stronger and more beautiful finish.

How densifiers work

During hydration, approximately 20 percent of a concrete mixtures Portland cement is converted to lime, which has no structural value in concrete. However, concrete densifiers react with the lime to form calcium silicate hydrate (CSH) crystals, the same type of mineral compound that acts as the binder in concrete and imparts strength. Once within the concrete, the sealant particles will travel through the extensive network of microscopic pores and hairline cracks, reacting chemically to form more calcium silicate hydrate (CSH), which is the crucial natural element to concretes strength. Additional CSH fills the pores in concrete and increases the hardness and stain resistance of the surface. With even more CSH present in the concrete after a concrete densifier is applied, the concrete is both denser and less prone to potential damage from water. This process is remarkably similar to how concrete is produced in the first place; thus, it is a good precautionary measure to take to improve the life of your concrete.