Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.
A new technology breakthrough was achieved during a recent Airports Company South
Africa (ACSA) project where warmed asphalt was produced with Recycled Asphalt (RA)
content of 55% using a foamed bitumen process. This was the highest amount of recycled
asphalt ever produced in an asphalt plant in South Africa.
The project involved the rehabilitation of the cargo area at OR Tambo International Airport
(ORTIA). The use of this environmentally sustainable technology resulted in massive cost
savings to the client and allowed the contractor to effectively work in a highly congested area
using conventional asphalt paving and milling equipment.
Various environmentally sustainable asphalt products have been used on ACSA airports
(including foamed treated asphalt with 35% RA, haul road with only RA with a surface
emulsion treatment, cold mixed RA mixes with emulsion, etc). This new approach was based
on the experience gained on previous ACSA projects where RA has effectively being used.
The paper will also discuss the use of RA of the full spectrum of applications from Hot mixed
asphalt with small amount of RA, asphalt with high contents of RA, warm mixes with RA, cold
mixes with RA (using foamed bitumen or emulsion) and the use of RA with a surface
treatment.
