Globally construction companies are working towards adopting sustainable practices that will help reduce material costs through measured usage and reuse of many materials. The reason for this is largely based on the increased material cost and the imperative towards environment friendly construction practices as well. Adopting such measures also attracts tax incentives and rebates which help in further reducing overall costs.
Recyclable construction material
A lot of construction material is recycled from waste products from demolished building. So, instead of carting of the debris from demolition they are recycled to create fresh construction material that are equally lasting. Some of the examples of such recycling of construction material are โ
- Recycle Concrete Aggregate (RCA) is a common construction waste that is produced after demolishing concrete structures
- Supplementary cementing materials (SCM) includes fly ash and slag which are industrial by-products and are used in concrete
Formerly used construction materials, such as Portland cement, have been a primary source for construction; however, they are no longer feasible, as they are difficult to transport and escalate costs a great deal. In addition, digging up fresh material is detrimental to the environment.
Recycled Concrete Aggregate
RCA is a new mechanism that is economic and environmental friendly. It is largely used as a granular base that is mixed with natural aggregate for concrete applications in road. Studies have proven that 30% RCA and 70% natural aggregate in high strength concrete product produces more concrete of similar strength than that containing only natural aggregate.
However, there is a risk of shrinkage with RCA in concrete of up to 10-30%. Also, RCA has low elastic modulus when compared with natural aggregate which contributes to drying shrinkage and creep. However, despite these drawbacks RCA can be used profitably and it will last long.
Increased use of recycled concrete
Due to the shortage in virgin concrete, there is an increase in use of recycled fine aggregate (RFA) along with the increased use in RCA.
RFA is taken from crushed waste concretes of varying qualities to turn into granite stone. It is used by replacing its contents of natural sand. Physically it is coarse with fine aggregates and its grade is determined by its fineness, gravity and water absorption propensity.
Summary:
Using RCA and RFA not only reduces waste but also greatly helps the environment and the economy as a whole. These materials have become precious resource and very important in concrete production due to the shortage in natural sands suitable for making concrete.
