Quality Assurance and Traceability of Recycled Materials Processed Continuously on Site

Title: Quality Assurance and Traceability of Recycled Materials Processed Continuously on Site
Author(s): Bonvallet
Paper category : conference
Book title: International RILEM Conference on the Use of Recycled Materials in Building and Structures
Editor(s): E. Vázquez, Ch. F. Hendriks and G.M.T. Janssen
Print-ISBN: 2-912143-52-7
e-ISBN: 2912143756
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 49 - 55
Total Pages: 7
Nb references: 5
Language: English

Abstract: On-the-road recycling processes are more and more complex and the engineers are willing
to use the conventional functions typical of stationary plants even when self-propelled
machines are to be employed on the job site. Today, the recycling of recycling asphalt product
(RAP) is becoming a primary concern in order to ensure long lasting treatments and good
adhesion of the recycled material to the remaining layers. As far as the first point is
concerned, the manufacturers have not succeeded in integrating the following functions with
the new recycling processes:
1. Particle size control of RAP and aggregates (if required),
2. Particle size correction by using an on-board crusher,
3. Continuous weighing of wet recycled material,
4. Continuous measuring of moisture contents in the recycled material,
5. Continuous addition of mixed binders, such as cement or modified bitumen emulsions,
according to the actual through-flow,
6. Change to the moisture contents in order to better control emulsion breaking for
optimum compaction.
Forced mixing of the elements by using a pugmill similar to those employed in stationary
plants.
The whole process is monitored through the use of an advanced controller so that the data
can be regularly transmitted via telephone modem to a service centre where the problems can
be diagnosed and instructions are given to change the operating procedures.
As far as the second point is concerned, a special machine has been developed. It comes
with cleaning brushes and an automatic collector for all the material to be recycled. The re-handled
material is stored on a thoroughly clean surface. An emulsion tack coat layer is
pulverized throughout the entire section by using a specific piece of equipment on board the
machine. This arrangement is essential to guarantee long service life and to ensure the layers
are firmly joined together.

Online publication: 2004-09-29
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143756.006