Testing the effectiveness of protective coatings on traditional bricks

For millenniums, bricks were the main building material for the load-bearing structural elements of constructions. They were produced manually and they were fired at low temperature. They also present low apparent specific density, high absorption, high surface roughness and relatively low compressive strength. Nowadays, bricks used for restoration works should be compatible to the old ones. As the existing line of modern brick manufacturing is far from the above mentioned criteria, the way to solve the problem is to manually produce these special building materials which render them expensive and laborious. Additionally, their high porosity and soft nature make them easily deteriorated by different environmental, conditions. The protection of traditional bricks is an important step towards their durability and a challenge especially nowadays where nanotechnology has been proven efficient when it is incorporated in coatings for building materials. In the present paper, hand-made brick samples were treated with different coatings by the technique of total immersion. The solutions tested were both traditional such as linseed oil but also silanes and alkosiloxanes both neat and nano-modified. In order to compare the physical properties of the treated bricks, parameters like capillarity, porosity, absorption and durability have been tested. It was concluded that silica nano-particles and micro-clay enrichment of alkosiloxane was the most sufficient way to protect those special building materials. (C) 2016 Elsevier Ltd. All rights reserved.