Mc-Bauchemie India Pvt Ltd

Sunny Surlaker, Head of Admixture Division with MC-Bauchemie India Private Limited interacts with Built Expressions elaborating the continuous focus on innovation and technology the company has adopted to establish a bench mark in the industry.

Sunny Surlaker

Head of Admixture Division, MC-Bauchemie Inia Pvt Ltd

BE: Along with a brief introduction of your organisation, can you describe the variants available under Protective Coating solutions for reinforced concrete?

SS: MC-Bauchemie (India) Private Limited is a leading name in Construction Chemicals, in terms of trust and reliability for over Twenty-Five Years in India. We manufacture over 200 construction chemicals in Technical and Financial Collaboration with MC-Bauchemie, Germany, a 50-year-old International organization. We are an ISO 9001: 2008 certified Company, and have a pan India presence through technically trained and qualified Channel Partners and IRP (Germany) trained applicators. Top-level technical advisors, support our Distribution Network. Our strength lies in Quality and Reliability. We provide technical services to solve constructional problems, in addition to detailed technical specifications and proposals. On-site, On-time delivery is our motto.

Our success is based on innovation, competence and service. These are the foundations for MC's Quality and international market reputation. New ideas, products and technologies emphasized and developed by MC have set the standards in many key areas. MC-Bauchemie, invests 10% of manpower and resources in R&D. By virtue of being collaborated we are immediately exposed to new technologies. The principals in MC-Bauchemie India head this initiative; bringing widespread experience and training from Europe, Brazil, US and Dubai to our structures and technology here in India. To apply our high-tech products, we train specialized contractors under proper supervision of qualified Civil Engineers. To maintain high technical standards, we are one of the few companies to have a dedicated training Centre and Concrete Technology Lab, in Goa, for our clients. International quality, Our Technical Backup and Reliability makes us successful in our field.

The application of protective coatings to reinforced concrete is an attempt to increase the effective concrete cover (to the reinforcement) in terms of both quality and quantity. By virtue of their formulations, anti-carbonation or other protective coatings provide the protection equivalent to meters of effective concrete cover in a very thin layer. Therefore the principle of equivalent cover is very valuable both in repair strategies and even to safeguard new structures that have a very long design life. Specialized protective coatings can be of many types:

• Thick Coatings (1-2mm): Like Different Breathable waterproof cementitious or mineral based polymer modified coatings
• Breathable, Elastic Elastomeric Crack bridging coatings (200-300 micron thickness)
• Breathable Hydrophobic impregnation coatings, based on silicone, silane-siloxane
• Resin based Coatings (Epoxy, PU, Polyurea, etc.)
• Specialized surface protection coatings can also be designed as anti grafitti treatments by making them self-cleaning type.

BE: What are the primary components of protective coatings?

SS: Very simply, concrete has two tendencies that render it susceptible to water and pollutants. Firstly Concrete has porosity due to capillarity and secondly concrete cracks. Therefore durability of concrete can only be enhanced by use of apt protective coatings that can form a physical and a chemical barrier against ingress of water, chlorides, CO₂ and SO₂. Paints and other decorative coatings are designed for aesthetic purposes and normally not for protection of concrete against carbonation, chloride attack, UV radiations and for crack bridging properties.

Although the main function of any surface protectant is moisture ingress control either by physical barrier concept or conversion of capillaries to hydrophobic, the coatings can also be designed for resisting chemicals. Chloride ingress can be effectively controlled by surface protectants. Further, the diffusivity of carbon dioxide, sulphur dioxide and oxygen can be lowered for corrosion control. Root and vegetation growth can be prevented in concretes under damp conditions.

Broadly speaking, the primary components of protective coatings are dependent on individual types of the coating listed above. From an application perspective, the main components of any protective system are a good/restored base concrete, proper surface preparation and technical application of the coating itself.

BE: How the basic types of coatings differentiated and what are the functional requirements of coatings for reinforced concrete?

SS: Coatings are differentiated based on their application and material base. Functionally, the challenge here is to choose the right coating for the right application.

According to international literature the following properties, are most essential for an excellent concrete protection system.

• Breathability - It is that property which enables the water vapor to move in and more importantly out of the concrete with the fluctuation of temperature and humidity. The water in concrete (or for that matter any porous media) tends to go from wetter to drier sections. Breathability is essential because, moisture movement in concrete may lead to osmotic pressure building up under non-breathable coatings and eventual debonding of the protective coating. Breathability also enhances drying of the internal concrete, arresting corrosion. Mineral based coatings or high performance acrylic polymer modified anti-carbonation elastic elastomeric coatings, provide much higher breathing capacity than most resin-based coatings, and thus can protect structures longer.  
• Impermeability to Water, CO₂ and other gases - Protective coatings should be permeable to water vapor, but impermeable to water. Though these properties look contradictory they must exist complimentarily. Most coatings do posses waterproofing characteristics, but are not breathable. This is the balancing point separating protective coatings from normal paints. In addition to water, it prevents ingress of corrosion causing gases into the concrete. Overall breathability and impermeability combined should form a protective coating not very unlike human skin. Good protective coatings provide a sound physical and chemical protection barrier to prevent corrosion in concrete, ensuring durability. These properties can be verified by adequate testing to ensure quality of coatings. The water absorption test is to be conducted as per DIN 52619. The testing for Diffusion Resistance against Carbon Dioxide is to be conducted as per DIN 53122 part 1 and the measurements are conducted as per procedure laid down by R. Engelfried titled "Carbonation: Its meaning and Influence through coatings”. 
• Crack Bridging - This is an important property as the coating should be able to negotiate expansions and contractions in the structure due to temperature or dynamic loads. It should also effectively seal and bridge over cracks, to ensure no water or gases enter concrete through them. Even after extensive weathering, protective coatings should provide excellent crack bridging capacities in a variety of static or dynamic loading conditions, in varying exposure conditions and even on weathered concrete surfaces. The testing for Crack Bridging Characteristic after weathering is done as per DIN 52231. 
• Ultraviolet (UV) rays resistance - For exterior application it is mandatory that the coatings should be UV stable. The effect of sunlight can cause certain polymers to become brittle and lose their physical and chemical properties. Exposure to sun can also leads to fading of pigments and differential colouring marring the beauty of the structures. Correctly designed protective coatings remain flexible even after exposure to sunlight without degrading.

BE: Which is the right protective coating? what are the selection criteria?

SS: Specifying protective coating is one of the difficult function qualified architects and engineers have to perform. There are so many factors to be considered, it becomes almost difficult to specify single coating. Some resort to generic raw material bases while others give more weightage to wet and dry film thickness. This creates ambiguity as high quality coating may perform better even at lower film thicknesses and when minimum thicknesses are specified, they become uneconomical while in reality they may be cheapest with respect to performance. First and foremost the specifier must clearly understand the protection requirements. It is therefore definite that specifications will change form project to project. Specifications should also depend upon the life span durability and protective quotient with respect to time. Cost calculations must be time dependent.

Rather than specifying coatings by generic names and film thickness it is preferable to specify them by performance requirements. Some performance properties that can be normally specified are:

• Diffusion resistance of CO₂
• Diffusion resistance against H₂O vapours, when designated as breathable coatings.
• Resistance against water penetration
• Resistance to chlorides (ponding)
• UV Resistance
• Crack Bridging ability under weathered conditions

BE: Can you briefly touch upon the emerging trends in the field of protective coatings?

SS: In terms of emerging trends, no particular revolutionary technology is coming up. However due to vast advances in polymer and resin technologies, anti-carbonation systems in particular have vastly improved. In addition, PU and resin technology too is improving drastically to provide easier application properties and better protective quotient.

Right now some of the top echelon constructors are paving the way for effective protection coatings, by combining the 3Ms of waterproofing success. Correct Materials, Trained and skilled Manpower and correct application Machinery and tools are the key to excellent protection systems. In this system, all agencies combine their expertise to deliver a defect free system to the end-user. Across the general market, a lot more awareness and training needs to come into play to ensure durability of our structures.

We can say that the emerging trends in this field are evolutionary rather than revolutionary and we see a bright future ahead.

BE: Can you throw some insight on protective coatings market? What are your company’s future plans to address the market need?

SS: Currently, protective coatings are a relatively small segment in the construction chemicals industry. However as awareness on increasing durability of structures goes, protection will be seen as an integral part of construction and the rehabilitation sectors.

Our coatings to enhance life expectancy of civil engineering assets are popular as they are crack bridging, carbonation-resistant and breathable. We have new generation environmentally friendly, liquid applied coatings to resist pH from 1 to 14. Being in technical and financial collaboration with MC-Germany, we have access to their international experience and expertise. An extensive innovative range of systems manufactured in India and a further portfolio of over 2500 materials from our collaborators, supplemented by excellent technical service, and providing customizable solutions will help us be competitive in the upcoming years.

We are in the high tech range of our industry. We solve problems and supply systems through free technical assistance. We do a lot of training for Engineers as well as our clients, which build effective technical partnerships for long-lasting solutions. We continuously go in for innovations and new developments. We cater to the quality conscious segment of the market and not the price sensitive segment because we never let ourselves forget the MC-Bauchemie has a worldwide reputation to keep. Our focus was and will always be Technical. With this approach, our customers keep coming back to us. We visualize all round success to our company. I believe in a future where we interact with our clients, not solely as a supplier, but also as a technical service partner.

We plan to achieve this and expand the awareness drive by means of our training centre and laboratory in Goa for maximum positive interaction with our customers. Our young team of marketing and technical executives and experts will ensure we expand our reach to meet the needs of the construction industry.