What does carbonation do to concrete?

Carbonation is the reaction of carbon dioxide in the environment with the calcium hydroxide in the cement paste. This reaction produces calcium carbonate and lowers the pH to around 9. At this value the protective oxide layer surrounding the reinforcing steel breaks down and corrosion becomes possible.

How do you mitigate carbonation in concrete?

Carbonation can be prevented or halted with the application of a protective anti-carbonation coating system. This should be specified for both new and existing structures. There are several products available: epoxy coatings; acrylic sealers; and silane sealers.

What is concrete carbonization?

Carbonation of concrete is the chemical reaction between carbon dioxide in the air and calcium hydroxide and hydrated calcium silicate in the concrete to give mainly carbonates. The formation of carbonates in these chemical reactions leads to a permanent sequestration of this CO 2.

Can carbonation strengthen concrete?

Simultaneously, the generation of carbonates by carbonation changes the pore structure of concrete, often increasing the density of the pore structure and thereby increasing the concrete strength.

How does carbonation affect durability of concrete?

Carbonation-induced corrosion can increase crack development and decrease concrete durability [5]. Carbonation reduces pH value and destroys the passive film around the steel, but it seems to densify concrete surface and reduce chloride ion permeability, reduce surface porosity and hence sorptivity in concrete [6-8].

What is anti-carbonation coating?

Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide. They protect concrete from carbonation by acting as a carbon dioxide barrier.

What is carbonation test of concrete?

Carbonation testing provides a means with which the inspector can determine the extent of carbon dioxide infiltration into the concrete. The process is similar to chloride ion testing where a sample is either removed, either by coring or drilling and the sample is tested by the application of a revealer.

What is concrete carbonation depth?

Carbonation depth is the average distance from the surface of concrete or mortar where carbon dioxide has reduced the alkalinity of the hydrated cement (NORDTEST, 1989).

Which factors affecting the carbonation of concrete?

Thus, the main factors affecting concrete carbonation are:

• Pore system of Hardened Concrete which in turn depends upon w/c ratio, type of binder, and degree of hydration,
• Relative humidity (for dissolution of Ca(OH)2),
• The concentration of CO2. Optimal conditions for carbonation occur at a RH of 50% (range 40–90%).

Where do you apply anti carbonation paint?

This 100% pure acrylic, waterbased, ultra-low VOC coating, is suitable for use on exterior and interior surfaces of concrete and anti-rust primed steel….Areas of use

1. Car park walls and ceilings.
2. Concrete civil structures.
3. Concrete bridges.
4. Concrete jetties.
5. Concrete viaducts.
6. Concrete soffits.

How does anti carbonation paint work?

A water based, CO2 inhibiting, water repellent protective coating for renovation and repair measures on concrete surfaces. A matt, water-borne and acrylate-based protective paint for concrete. It protects concrete from carbonation. A waterproof sol silicate based paint that protects against carbonation and chloride.

What is the purpose of carbonation test?

Which chemical is used for carbonation test?

phenolphthalein
Concrete Carbonation is tested with the straightforward use of a chemical indicator; the most commonly used indicator is a solution of phenolphthalein in alcohol and/or water. Phenolphthalein solution applied to fresh strongly alkaline concrete will turn pink.

How do you calculate carbonation depth?

The carbonation depth is approximately proportional to the square root of time. For example, if the carbonation depth is 1mm in a one-year-old concrete, it will be about 3mm after 9 years, 5mm after 25 years and 10mm after 100 years.

Why is carbonation so good?

These fizzy drinks have an acidic bite and produce a pleasant tingling, cooling sensation with every sip. The bubbles also carry the aroma of the beverage to engage your sense of smell as well as taste. This added flavor helps enhance many of our favorite beverages.

What is the carbonation process?

Carbonation is the chemical reaction of carbon dioxide to give carbonates, bicarbonates, and carbonic acid. In chemistry, the term is sometimes used in place of carboxylation, which refers to the formation of carboxylic acids. In inorganic chemistry and geology, carbonation is common.

What does anti carbonation paint do?

Where is anti carbonation paint used?

Anti carbonation is used as protective & decorative coating for bridges, flyovers, subways, underpass, parking garages, tunnels, chimneys, industrial structures, stadiums, and RCC water tanks.