Monday, December 11, 2017

Company Profile - Perma Construction Aids Pvt Ltd

Waterproof, the right way!

 

 

Perma Construction Aids Pvt Ltd, a reputed name in the field of construction and waterproofing solutions, offers an insight into the general practices in the waterproofing systems and highlights the modern methodologies

 

For present day construction, builders have various waterproofing systems to choose from. Some systems are old and conventional but still practiced successfully; the modern systems are implemented taking the materials and structural behavior into consideration. Some of these compounds, also known as integral waterproofing compounds, are based on plasticizing and air-entrainment or water repellence principles. These act as good waterproofing precautions when other factors such as good mix-design, proper mixing/placing, compacting/curing etc. are taken care of. Various time-tested products that have extended their stay in the market include bituminous treatment, metallic sheet wrapping, polyurethane based waterproofing treatment, epoxy based water proofing treatment and box type water proofing system.

 

 

 

New Age Techniques

 

Presently there are numerous modern techniques in waterproofing available in the market that understand the functional behavior of the structure, the properties of the materials and such systems can be incorporated at the design stage only. A single product or technique is usually not enough, involvement of various bodies and techniques in coordination is essential for making structures waterproof. For success of any system, the building structure should have sufficient and efficient control joints if the slabs dimensions are more than 20 m in any direction. These joints are supposed to be designed and their configuration marked on the drawings and their detailing needs to be given with respect to waterproofing system proposed in large buildings. Different types of control joints are construction joints or day joint, crack inducer joint, contraction joint and expansion joint. Coefficient of thermal expansion of concrete is between 6 to 10 X 10^-6 mm/mm/oC.  If proper control joints are not provided in large slabs, no waterproofing system will work. Modern technique relies basically on two main waterproofing systems, which are foolproof and simple. These systems are crystalline waterproofing system and flexible membrane water proofing system

 

 

 

Crystalline Waterproofing System

 

This system involves blocking the water bearing capillaries with insoluble crystals. This method is used for waterproofing water-retaining structures like overhead/underground water tanks, sunk slabs of bathrooms and toilets, swimming pools, basements, terrace gardens etc. The method of treatment involves saturating the surface to be treated with water and then mixing two-and-half volume of the powder with one volume of water to form neat consistency hot slurry. The active ingredients in the slurry then pass through the water bearing capillaries and react with calcium oxide in the concrete to form insoluble crystals, which effectively block the capillaries. Further the chemical ingredients of the product remain in concrete to reactivate the process of crystallisation as and when a new capillary is developed. This system of water proofing the water-retaining structures is practiced in all the
developed countries.

 

 

 

Flexible Membrane Waterproofing System     

 

The main product used in this system comprises two components one liquid and the other is a powder packed roughly in the proportion of 1:4 by weight. The liquid component is an acrylic emulsion and the powder component is a polymer-modified cement with film forming chemicals and fillers, and some manufacturers add reinforcing fibres to make the product extra effective. These two ingredients are mixed together to form a consistent slurry. This slurry when brushed on to the roof surface forms a flexible film on drying. Since cement is an ingredient in this product, it has excellent compatibility with concrete. The film further allows the breathability of the concrete without any hindrance hence there is no problem of its de-lamination from the concrete surface. This film being flexible takes care of the deflections in the slab and the movements caused because of primary or secondary settlements, movements due to wind loads and temperature stresses developed in the concrete. This system can be used on surfaces, which had bituminous treatment earlier. In European countries this type of product is used as coating on pre-stressed concrete bridge girders to protect them from aggressive chemical atmosphere.

 

 

 

Failures of Waterproofing

 

Especially in large buildings, water-proofing systems fail if the control joints are not in position or not properly executed. This failure occurs after the structure has survived one complete season cycle. One can’t repair these types of failures. It needs a different type of approach involving provision of crack inducer joints and then tackling the waterproofing in movement restricted bays. Stretching the coverage of the products beyond the specified limits by the manufacturer also results in a failure.

Generally, architects in India do not emphasise on waterproofing details and structural designers give least importance to the control joints. As a result of this many systems have failed in several prestigious buildings. The client should insist on the architect to provide waterproofing design details including selection of specified material in advance so that no ambiguity remains till the end.
 

 

 

For further info:

Email: info@permaindia.com

Website : www.permaindia.com/
                 www.permaindia.net




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