Better Buildings with VINNAPAS®
WACKER dispersible polymer powders make dry-mix mortar more flexible and improve its adhesion and processing properties. For example, modified mortars can be used to lay autoclaved aerated concrete (AAC) blocks by the thin-bed method – an advantage greatly appreciated by construction experts in emerging markets such as India.
A view over suburban Mumbai: the metropolitan region on India’s west coast has more than 18 million inhabitants and is the country’s economic powerhouse.
India is a country of young people – half of its 1.3 billion inhabitants are under 25, and sooner or later they will need somewhere to live. At the same time, ever more Indians are benefiting from the economic boom and want to acquire their own home – in many cases near their place of work as well as in their native city. As a result, the construction market is booming – according to auditors at PwC, it is set to grow by seven to eight percent in the coming years – the second highest growth rate in the whole of Asia.
“To realize all the projects that have been planned and are necessary, we must slash the conventional construction time,” says Dr. Priti Pillay, a trained chemist and head of WACKER’s Technical Service Center in Mumbai. That was why contractors temporarily replaced traditional bricks with concrete blocks, which are easier to lay, since they are perfectly uniform, continues Dr. Pillay. “Though in the long run, they are not really suitable for use in residential buildings, since they are too heavy.”
Porous Materials Insulate Well
VINNAPAS®-modified dry-mix mortar – shown here in a lab test – is easier to spread and process.
Contractors, therefore, are now turning to aerated concrete, which is familiar in Europe under the trade name Ytong. The blocks are lightweight, fit together accurately, can be cut to size by hand, and, because of their porous structure, they also have very good thermal insulation properties. When used with the right mortar, they can be even further optimized. “Conventional thick-bed mortar is applied in layers of one to two centimeters, which poses several problems,” she says. “Poor bonding is one of the drawbacks.”
Dr. Pillay therefore advises her customers to use thin-bed mortar, which is modified with VINNAPAS® dispersible polymer powder from WACKER. If the dispersible polymer powder is added to conventional dry-mix mortar in advance, the bricklayer on site only needs to add water – no precise dosing instructions are required. “That makes factory-manufactured dry-mix mortar inherently less error-prone, since optimizing the properties is simply a matter of adding the right amount of water,” she adds.