Demolition and recycling - Options for recycled brick material

Other options

applications of reused bricks

The above-mentioned options for recycling clay bricks and roofing tiles are the most notable. In some countries (e.g. the Netherlands) a possible reduction of masonry waste from infrastructure works is expected to occur in a few years. This will dictate the need for new national and regional strategies.

Bricks and roof tiles have traditionally been regarded as important materials as after demolition they have often been incorporated into new buildings. In many countries, this traditional way of recycling is still used. By using old bricks and tiles, it is possible to endow buildings with a unique appearance.

However, it should be remembered that:

• Cleaning bricks is time consuming, difficult and dusty work that, if mechanised, is rarely successful. New techniques should be applied to tackle such problems.
• Cement rich mortars are difficult to remove. In countries like Greece, where mortar from ancient constructions is a full ceramic material, it does not need to be removed.
• Excess mortar dust can inhibit the adhesion between mortar and bricks and lead to weaker masonry, depending on the mortar composition.
• Bricks from demolished buildings may vary in quality. It is therefore difficult to assess the strength and load-bearing capacity of masonry made from recycled bricks. European and national standards are very strict and it is extremely difficult to be sure that recycled bricks used in new structures will be durable.
• Due to the difficult nature and high labour costs associated with the process, the use of recycled bricks may be more expensive than the use of new bricks.

The stability and porosity of recycled brick renders it suitable for use as a fill or surfacing material in roads and trenches. Other possibilities will no doubt be found for future applications.
Bricks, roofing tiles and other recycled masonry have chemical compositions that may be compatible for use with other building products fired at high temperatures. Possibilities therefore exist for combinations with materials such as cement and mineral wool.

Finely ground clay brick and roofing tile materials have a pozzolanic effect. Due to the presence of reactive silica, the material can form a binding mixture when mixed with lime or lime-containing materials, such as cement. This effect can be used in mortars and concrete. The practice was adopted by the Romans and exploited by numerous cultures ever since. Current investigations may show that this is an important use for recycling clay bricks and roof tiles.

Scientific institutes and universities are embarking on an increasing amount of research to further our knowledge in this sphere. In the Netherlands, one project studies the separation of mixed building and demolition waste materials and the re-use of each type. After selective demolition, heat is used to remove mortar from bricks in order to allow re-use in housing. In cases where the mortar is a full ceramic material, as in Greece, separation would not be needed and would thus render re-use a lot easier.

In all other cases where bricks and mortar are separated, tests have shown that the whole brick still conforms to technical standards. This proofs that ceramic building products have enduring qualities that are suited to sustainable construction.

»The Clay Life Cycle    »  Demolition and Recycling » A longer life for buildings » Demolition of buildings » European policy » Options for recycled brick material     ·  Filling and stabilizing material for infrastructure     ·  Aggregates for in-situ and precast concrete     ·  Aggregates for calcium silicate bricks     ·  Tennis sand     ·  Plant substrates     ·  Other options
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