As agriculturalists, there is great importance in studying farming practices that mimic natural systems. doi: 10.1016/j.resconrec.2006.05.010.From last year’s Cooking with Food Waste workshop to the upcoming installment of the developing Waste Not series, Living Web Farms is making a point to not only reduce waste, but help change the perspective on waste all together. "Use of aggregates from recycled construction and demolition waste in concrete". Wright, Jr, "FHWA Recycled Materials Policy", Federal Highway Administration, November 20, 2006. ^ a b "Markets for Recycled Concrete Aggregate" Archived at the Wayback Machine,.Ohio Department of Natural Resources Division of Soil and Water Resources. ^ "How Concrete is Recycled" Archived at the Wayback Machine,.^ a b "Value Engineering Benefits" Archived at the Wayback Machine,.^ a b c "What are Benefits of Recycling? - Conserve Energy Future".International Journal of Concrete Structures and Materials.
"Strength and Durability Evaluation of Recycled Aggregate Concrete". ^ Yehia, Sherif Helal, Kareem Abusharkh, Anaam Zaher, Amani Istaitiyeh, Hiba ().^ "Urbanite - Reusing Old Concrete - The Concrete Network".This can be remedied by mixing in materials such as fly ash. Some experiments showed that recycled concrete is less strong and durable than concrete from natural aggregate. The Army Corps of Engineers' Construction Engineering Research Laboratory (CERL) and others have studied the risks, and concluded that concrete with lead-based paint should be safely used as fill without an impervious cover as long as it is covered by soil. There have been concerns about the recycling of painted concrete due to possible lead content. Wire gabions (cages), can be filled with crushed concrete and stacked as retaining walls or privacy walls (instead of fencing). Well-graded and aesthetically pleasing materials can be used as landscaping stone and mulch.
Ĭrushed concrete free of contaminants can be used as raw material (sometimes mixed with natural aggregate) to make new concrete. Concrete pavements can be broken in place and used as a base layer for an asphalt pavement through a process called rubblization. The US Federal Highway Administration may use such techniques to build new highways from the materials of old highways. Sub-base gravel is laid as the lowest layer in a road, with fresh concrete or asphalt poured over it. Small pieces are used as gravel for new construction projects. Large pieces of concrete rubble (urbanite) can be used in walls as building stones, as slabs in walkways, or as riprap revetments to reduce stream bank erosion. Crusher attachments to construction equipment such as excavators can crush up to 100 tons per hour and make crushing of smaller volumes economical. Compact, self-contained crushers can crush up to 150 tons per hour and fit into tighter areas. These systems normally include a side discharge conveyor, a screening plant, and a return conveyor from the screen back to the crusher for re-crushing large chunks. Large road-portable plants can crush concrete and asphalt rubble at 600 tons per hour.
Ĭrushing at the construction site using portable crushers is cheaper and causes less pollution than transporting material to and from a quarry. The pieces can be shaped, for example using a chisel this can be labor-intensive.Ĭrushing involves removing trash, wood and paper removing metals such as rebar, using magnets and other devices, to be recycled separately sorting the aggregate by size crushing it using a crushing machine and removing other particulates by methods such as hand-picking and water flotation. Re-purposing urbanite (concrete rubble pieces) involves selecting and transporting the pieces, and using them as slabs or bricks. Reduces costs of transporting materials and waste.Reduces pollution from transport to landfills and dumps.Recycling one ton of cement can save 1,360 gallons water, 900 kg of CO 2. Conserves natural resources compared gravel mining.This, along with the resource use of this construction, has caused more and more countries to consider the importance of recycling of demolition waste. The most common way to dispose this waste is to dump it in a landfill, which can pollute the air and water. Demolition to make space for new structures generates a large volume of waste. The demand of construction aggregate was projected to reach 48.3 billion metric tons by 2015 the highest consumption was to be in Asia and the Pacific.