Description
Through a combined action of the State and the private sector company, preliminary studies to establish the massive use of tyre rubber in asphalt pavements are being currently developed in Chile.
Some precedents about systems of preparation of crushed tyre rubber and ways of incorporation in several asphalt applications were collected. Then, a hot asphalt mix was chosen as the first application to be studied.
Each of the constituents was previously analysed: asphalt cement, tyre rubber, aggregates with reference to Chilean and foreign specifications. Afterwards, asphalt-rubber (humid 1 method) was dosed and with this binder the Marshall dosage of asphalt mix with two-gradation aggregates Dense and Semi Gap Graded, was studied.
The asphalt- rubber was assessed with tests of Viscosity, Softening point,, Penetration at 4ºC and 25ºC and resilience, being the % of rubber, the energy, temperature and stir time defined by Taguchi, on the basis of regulation ASTM D 6114.
The asphalt mix was assessed with tests of immersion-compression, indirect traction and wheel tracking, referring the results to foreign specifications. Laboratory results ratify the technical convenience of incorporating crushed tyre rubber to hot asphalt mixes.
In 2003 and 2004, this technology will be applied in two roads to prove the technical and economic feasibility in the field.
