SRT750 Sustainable Futures - T2/2018: Concrete Waste Aggregate Report

This report examines the concept of utilizing waste materials, such as unused concrete, bricks, blocks, gypsum, plastics, and glass, as aggregates in concrete. It explores the waste hierarchy of reduce, reuse, and recycle, emphasizing the sustainable use of these wastes. The report discusses the utility of glass and plastic as cement aggregates, highlighting their impact on workability and strength. It also addresses the limitations of this approach, such as potential decreases in compressive and tensile strength when recycled materials are used. The report references several studies that support the feasibility and challenges of employing waste aggregates in concrete, providing a comprehensive overview of this innovative waste reuse strategy for sustainable construction.

CONCRETE USING WASTE AS AGGREGATE: A NOVEL WASTE REUSE STRATEGY
What is waste aggregate in concrete?
Wastes like plastics, glass and recycled cement can be used
as an aggregate in cement.
Plastic as cement aggregate
Glass as cement aggregate
Recycled cement as cement aggregate
Waste can be reduced by the following ways
Utility of the concept
• glass as a substitute of and had no impact on the workability of concrete.
• Adding the waste plastics into the concrete at varying percentages had different
effect on the strength of the concrete.
• increase in percentage of the plastic material leads to decreased compressive
strength
Limitations
• The substitution of the natural aggregates with the recycled materials leads
to decrease in the compressive strength of the aggregate.
• The usage of the recycled concrete along with the fresh concrete decreases
the mechanical performance of the concrete.
• Tensile strength of the concrete decrease where there is a 100 percent of
the recycled aggregates are used.
Reference
Al-Gahtani, K., Alsulaihi, I., Ali, M. and Marzouk, M., 2017. Production of green concrete using recycled waste
aggregate and byproducts. Built Environment Project and Asset Management, 7(4), pp.413-425.
Sérifou, M., Sbartai, Z.M., Yotte, S., Boffoue, M.O., Emeruwa, E. and Bos, F., 2013. A study of concrete made with
fine and coarse aggregates recycled from fresh concrete waste. Journal of Construction Engineering, 2013.
Teara, A., Ing, D.S. and Tam, V.W., 2018, April. The use of waste materials for concrete production in construction
applications. In IOP Conference Series: Materials Science and Engineering (Vol. 342, No. 1, p. 012062). IOP
Publishing.
Zhu, X. and Xue, T., 2013, June. Studying on the Recycled Concrete of Performance and Prospect. In Digital
Manufacturing and Automation (ICDMA), 2013 Fourth International Conference on (pp. 1354-1356). IEEE.
Wastes cannot be eliminated but it can be managed
through:
• Sustainable use of the wastes called “waste
hierarchy”
• Reduce, reuse and recycle of wastes
• Wastes disposal methods
The typical construction site
generates the following major wastes
which can be used as aggregates in
concretes:
• Unused concrete, bricks and
blocks, gypsum
• plastics
• glass