ROAD PAVEMENT FORUM MAY 2007

ASPHALT RECYCLING

Recycling

• Energy consumption of recycled asphalt layers can be as little as 25% of that needed for new layers

• Ever increasing cost of fuel, bitumen and aggregates should result in the cost of recycled pavements rising at a much slower rate than that for virgin material

• Road owners utilising materials they already own makes a lot of sense!

Asphalt recycling

Current situation in South Africa

Asphalt recycling

• No major recycling on road projects for 10 years?

Recycling Possible reasons for limited recycling:• Actual quantities of RAP available?• Variability of RAP?• Limited use of HMA bases?• Insufficient stock pile areas at batching plants?• No crushing facilities at batching plants• Logistics of keeping RAP stockpiles dry?• Availability of suitable mixing plants?• “Perceived or real” poorer performance of recycled asphalt?• Not a legal requirement?

Asphalt recycling

Current situation of RAP in South Africa:• Frequently utilised in cement stabilised

subbase layers (≤ 40%)• Frequently utilised as shoulder make-up

material• Cold or hot recycled as subbase layers

under concrete pavements• Utilised by manufacturers for “grocery

trade”?

Asphalt recycling

Utilizing 10% RAP = recycling

or black aggregate??