Construction Waste Recycling
- The promotion of enviornmental management and the mission of sustainable development have exerted the pressure demanding for the adoption of proper methods to protect the enviornment across all industries including construction.
- Construction by nature is not an eco-friendly activity.
- Construction,renovation and demolition activities leads to the formation of waste.
Need For Adoption Of Proper Methods Of Recycling
Aggregate From Construction And Demolition Waste
- Recycled precast elements and cubes after testing (the aggregate could be relatively clean with only cement paste adhering to it).
- Demolished concrete building(aggregate could be contaminated with bricks and tiles, sand and dust, timber, plastics, cardboard and paper and metals.)
- Used as a subtitle for natural coarse aggregates in concrete
It has been generally accepted that recycled aggregates either fine or coarse can be obtained by primary and secondary crushing and subsequent removal of impurities.The best particle distribution can be achieved by primary crushing and then secondary crushing, but a single crushing process is more effective from the economic point of view.
The water absorption in Recycled Aggregates ranges from ( 3-12% ), this value is much higher than that of natural aggregates whose absorption is about ( 0.5- 1 % ).
Use of such aggregates as sub base in flexible pavements show promising results. These recycled aggregates have also been used in generating concrete that is further used in rigid pavements .
Properties Of Fresh Recycled Aggregate Concrete
Timber waste from construction and demolition works is produced in large quantity all over the world.Whole timber arising from construction and demolition works can be utilized easily and directly for reused in other construction projects after cleaning, denailing and sizing.
Barriers In Promoting Use Of Recycled Materials
- Lack of appropriately located recycling facilities.
- Absence of appropriate technology.
- Lack of awareness
In order to reduce the construction waste, during the time of construction order only the correct amount of raw materials. Proper care should be taken to ensure the protection of materials being delivered and stored in the site. When a structure is being demolished, salvage as much of the more valuable fittings and materials as possible. Any suitable substitute for aggregate should be considered during the construction. It is the duty of an engineer to revaluvate technical specification for materials where strength and safety do not have to be compromised to permit the use of recycled materials. As sorting and recycling facilities become more wide spread and better developed it will be easier to redirect our waste from landfill.