Admixtures to make structures more durable

 Civil engineering is known as mother of all engineering branches. Construction and building material sciences is a highly matured technology, world over. What one builds brick-by-brick, may get destroyed, drop-by-drop seepage of water. To avoid premature deterioration of the buildings and other concrete infrastructure facilities, a scientific approach towards waterproofing is essential to avoid leakages and seepage. Durable concrete structures can be achieved only through careful attention to many details.

Admixtures play an important role in today’s concreting to get durable concrete structures:

Types of admixtures
• Accelerating admixtures (ShaliPlast FS)
• Retarding admixtures (ShaliPlast R)
• Water reducing admixtures (ShaliPlast SP/PCE)
• Air entraining admixtures (ShaliPlast AE)
• Shotcrete Admixture ( ShaliPlast Shortcrete P/L).

Advantages
• Shortens the setting time of cement and therefore increases the rate of gain of strength.
• Improves workability, cohesion and extends setting time, provides protection against delays and stoppages and facilitates keeping workable concrete for extended period.
• In the large construction, good workability of the concrete throughout the placing period and prevention of cold joints is ensured by adding retarders in the concrete.
• Enables earlier release from precast moulds thus speeding guidelines on use of admixtures in concrete production.
• Reduces segregation and increase density and compressive strength.
• Early use of concrete floors by accelerating the setting of concrete.
• Reduces water requirements, bleeding, shrinkage and time required for initial set.
General concrete deterioration
Most concrete deterioration can be attributed to water penetration. Since concrete absorbs moisture until it becomes saturated. Moisture hastens deterioration not only because it promotes chemical reactions but also because it carries dissolved chemicals that can react with the steel, lime and other components in the concrete. It also plays a major role in concrete deterioration and water entering into concrete results in spalling of concrete.

Migratory Corrosion Inhibitor  ( ShaliPlast RCI)
Migratory corrosion inhibitor, being Amine based bipolar in nature, used as an additive during concreting or repairing, can protect the steel from corrosion in aggressive environment.

Steel in reinforced concrete is prone to chemical attack in certain corrosive environments.  The liquid membranes (bitumen, resin, acrylic, polyurethane, water or solvent based, in one or two-components) can be used in civil, industrial projects.

Their main application is waterproofing of roofs, balconies, terraces, roof-gardens and planters tubs, walls, parking lots and concrete structures, but also they can be used to waterproof surfaces and concrete walls, against-ground water. Apart from other brands, STP Ltd is one of the pioneer companies for waterproofing which was established well back in 1935 Trusted for generations, STP has some of the largest range of new generation and traditional waterproofing products in India. 

In recent past, usage of admixtures has increased, as the construction industry had grown on a sustainable basis. Concrete sections are getting thinner and hence require higher grade of concrete, which can be achieved mainly by use of admixtures.  

Authored by Hasan Rizvi, Vice President, STP Ltd.