Concrete densifier
Encyclopedia
A concrete densifier is a chemical applied to a concrete
surface
in order to fill pores
, increasing surface density
. Chemical densifiers are used on polished and non-polished concrete to reduce dusting and wear
; on polished concrete
surfaces densifiers help concrete take a better polish and make the surface less permeable to liquids so the slab does not require sealing.
uses densifiers to achieve a better shine. Polishing works by smoothing out peaks and valleys in the surface; if the concrete is not strong enough, this abrasion will remove micro-chunks that decrease the surface uniformity and quality of shine. Concrete surfaces face two major obstacles to polishing: bleed water and pores
.
Excess water in newly placed concrete rises to the surface. This bleed water carries with it the finest aggregate and laitance, making it much softer than the slab's core. It also increases the water to cement ratio, which further weakens the surface. Densifiers address this problem by binding to available lime
in a pozzolanic fashion, creating additional cementitious material and strengthening the surface.
Concrete is by nature a porous material, with pores formed by water evaporation during curing. These pores interfere with surface uniformity, and make the slab more susceptible to staining from spilled liquids. The additional cementitious material formed by the densifier and lime tightens these pores for better surface hardness and durabilty. Most densifiers can react within 1-2 hours with concrete surface, however the chemical reaction with the calcium and free lime in the concrete will continue for up to 2 months after the application of it to the surface of the concrete.
Densifiers may use various carrying agents to accomplish the hardening process, potassium, sodium, lithium, or other agents.
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...
in order to fill pores
Porosity
Porosity or void fraction is a measure of the void spaces in a material, and is a fraction of the volume of voids over the total volume, between 0–1, or as a percentage between 0–100%...
, increasing surface density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
. Chemical densifiers are used on polished and non-polished concrete to reduce dusting and wear
Wear
In materials science, wear is erosion or sideways displacement of material from its "derivative" and original position on a solid surface performed by the action of another surface....
; on polished concrete
Polished concrete
Polished concrete is concrete that has been treated with a chemical densifier and ground with progressively finer grinding tools. The grinding tools are usually progressive grits of diamond grinding cup wheels and diamond polishing pads. Typically, concrete is not considered polished before 400...
surfaces densifiers help concrete take a better polish and make the surface less permeable to liquids so the slab does not require sealing.
Polished concrete
Concrete polishingPolished concrete
Polished concrete is concrete that has been treated with a chemical densifier and ground with progressively finer grinding tools. The grinding tools are usually progressive grits of diamond grinding cup wheels and diamond polishing pads. Typically, concrete is not considered polished before 400...
uses densifiers to achieve a better shine. Polishing works by smoothing out peaks and valleys in the surface; if the concrete is not strong enough, this abrasion will remove micro-chunks that decrease the surface uniformity and quality of shine. Concrete surfaces face two major obstacles to polishing: bleed water and pores
Porosity
Porosity or void fraction is a measure of the void spaces in a material, and is a fraction of the volume of voids over the total volume, between 0–1, or as a percentage between 0–100%...
.
Excess water in newly placed concrete rises to the surface. This bleed water carries with it the finest aggregate and laitance, making it much softer than the slab's core. It also increases the water to cement ratio, which further weakens the surface. Densifiers address this problem by binding to available lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...
in a pozzolanic fashion, creating additional cementitious material and strengthening the surface.
Concrete is by nature a porous material, with pores formed by water evaporation during curing. These pores interfere with surface uniformity, and make the slab more susceptible to staining from spilled liquids. The additional cementitious material formed by the densifier and lime tightens these pores for better surface hardness and durabilty. Most densifiers can react within 1-2 hours with concrete surface, however the chemical reaction with the calcium and free lime in the concrete will continue for up to 2 months after the application of it to the surface of the concrete.
Densifiers may use various carrying agents to accomplish the hardening process, potassium, sodium, lithium, or other agents.