Recycled aggregate refers to crushed or processed material obtained from construction and demolition waste, which can be reused in construction projects.

Recycled aggregate refers to crushed or processed material obtained from construction and demolition waste, which can be reused in construction projects.

1. CONCRETE TECHNOLOGY ( BCV503) RECYCLED AGGREGATE 4/10/24

2. Introduction Recycled aggregate refers to crushed or processed material obtained from construction and demolition waste, which can be reused in construction projects. It typically comes from sources like demolished concrete, asphalt, or brick and is processed to meet specific size and quality standards for use in new construction. Recycled aggregate is commonly used in applications like road base, sub-base, and sometimes in new concrete mixes, helping to reduce the environmental impact of sourcing new materials.

3. Road Base Sub-Base

4. Characteristics of recycle aggregate concrete Recycled aggregate concrete has a crushed sound and clean waste concrete of at least 95% by weight of concrete with typical total contamination lower than 1% of the bulk mass Class 1A RCA is a well graded RCA with no more than 0.5% brick content

5. Classification and properties of recycled aggregate concrete Material composition is the basis for classification of recycled concrete aggregate in two main types- 1) Crushed concrete 2) Mixed material Each of these types in divided in a class for bound and a class for unbound use

6. 1) Crushed concrete – This materials generally resultant in increased water demand and decreased workability 2 ) Mixed concrete – mixed concrete remain plastic for a short time. This properties are important because they affect the cost quality and in place cost of the hardened concrete

7. Process of recycle aggregate concrete Crushing Pre-sizing Sorting Screening Contaminant elimination

8. Process of recycled aggregate concrete

9. Crushing and screening systems start with primary jaws cones and larger impactor taking rubble from 30 inches to 4 feet. A secondary cone may or may not need to be run, and then primary and secondary screens may or may not be used depending upon the project ,the equipment used and the final product desired. A scalping screen will remove dirt and foreign particles . A fine harp deck screen will remove fine material from coarse aggregate. Further cleaning is necessary to ensure the recycled concrete product is free of dirt , clay, wood, plastic and organic materials. This is done by water floatation ,hand picking , air separators, and electromagnetic separators.

10. Uses of recycle aggregate concrete

11. Uses of Recycled Aggregate Recycled aggregates can be of two types – processed and unprocessed. Different types can be used for different types of construction works. Unprocessed recycled aggregates are used for: Bulk fill Base fill for drainage structure Aggregate for road construction Riverbank protection

12. Processed recycled aggregates are used for: Aggregate in lean concrete Aggregate in bituminous concrete Structural works in bridges Pavement Shoulders Median barriers Sidewalk Curbs

13. Benefits of recycled aggregate concrete Conserves natural resources Reduces landfill waste Decreases environmental impact Cost-effective Improves sustainability

14. Advantages Disadvantage Environmental impact 1. Lower strength Durability 2. Lower workability Energy use 3. Water absorption Water absorption 4. Porosity Tax rebates 5. Density Cost 6. Macroscopic properties

15. THANK YOU Presented by : Ashwini G 4NI22CV015