Concrete Restoration

Introduction

Challenges

Concrete and strong cemented surface normally does not require a great attention as compared to any other construction material. However, it deteriorates under certain conditions of exposure. For instance, carbon dioxide of the atmospheric air reacts with the alkaline components in concrete in presence of moisture and produces calcium carbonate. The pH value of the pore water therefore reduces, and corrosion sets in. Due to this there may be perpetual problems in its service life and that calls for many innovative techniques specialized rehabilitation.

Solutions

We at IBCS have complete solution for restoring the concrete structure and complete building construction. We take up:

Anticorrosive treatment for rebars and steel structures
Column and beam encasement with micro-concrete
Polymer modified & Structural grade, shrinkage compensated repairs mortars
Guniting and shotcreting
Cosmetic repairs to façade
Anti-carbonating, waterproofing and breathable facade painting

Significance

Concrete Structures weaken with time due to variety of factors. These factors include the following environmental agents:

RELEVANCE OF CO2 AND CL TRANSMISSION RATE

Cement or concrete are highly alkaline and create a highly alkaline environment around the bare steel reinforcing rods.
Steel will not rust in high alkalinity conditions, so the concrete provides a ‘passive’ environment in which the reinforcing steel exists.
This passive environment can be destroyed by acid attack neutralizing the alkalinity or by insufficient concrete cover over the steel.
High carbon dioxide levels normally exist in high traffic areas and emanate principally from traffic emissions.
Carbon dioxide mixed with water produces carbonic acid which will neutralize the alkalinity of the concrete around the reinforcing steel.
High chloride ion levels normally exist in coastal areas subjected to higher salt prone atmospheres.
Chloride ions mixed with water produces hydrochloric acid which will neutralize the alkalinity of the concrete around the reinforcing steel.

RELEVANCE OF SULPHIDE ION TRANSMISSION RATES

High levels of sulphide ions normally exist in high traffic areas such as CBD’s from vehicle emissions and some industrial areas such as around petroleum refineries.
Sulphide ions form sulphuric acid when mixed with water and attack concrete and brick in the same way as chloride ions.