Highway Research Record

VI. RESEARCH WORK DONE IN ACADEMIC INSTITUTIONS RELATED TO THESIS WORK
B. PAVEMENT ENGINEERING AND PAVING MATERIALS
Studies on Porous Asphalt Mix with Polymer Modified Bitumen

Date of Start:December 2003 to November 2004
College of Engineering, Thiruvananthapuram (R, I)

Present Status and Progress
Completed

Findings/Conclusions
(i) The percentage of fines and binder content to the total weight of the mix is optimized to 15% and 5.43% respectively.
(ii) The coefficient of permeability obtained for the optimized mix is 0.304 cm/s which is enough to drain down the storm      water.
(iii) In the porous asphalt mixes the binder run-off increases with increase in the binder content and this limits the binder      content.
(iv) Air void contents obtained for optimized mix is 17.2 %, and the trend showed that void contents decreased with increase      in binder content as well as fines content.
(v) The porous mix are resistant to plastic deformation due to low fines content and offers high skid resistance because of      single sized aggregate skeleton.
(vi) The coefficient of skid resistance obtained for the porous asphalt mix was found higher than that of conventional       pavements. The coefficient of skid resistance obtained for the optimized mix was 74.
(vii) The use of modified bitumen allow the higher binder content (5.43%) in the mix there by increased film thickness over       the aggregate skeleton which significantly influenced the drain down characteristics, abrasion resistance and resistance to        ageing.
(viii) Relative fatigue life of the optimized mix was found to be 1.18.

Recommendations
(i) A detailed test strategy including, the fatigue tests, permanent deformation, durability tests and cost analysis need to be      carried out to find the economic life, resistance to deformation, durability and economy in construction when applied in      fields
(ii) Trial tracks with porous asphalt mix could be carried out to evaluate the structural and functional characteristics of      pavements.
(iii) Studies can also be conducted on resistance to fuel spillage, effect of load repetition etc.

Report/Publication

Lakshmanam.M.P (2005), “Studies on Porous Asphalt Mix with Polymer Modified Bitumen”, M.Tech Thesis, Traffic and Transportation Engineering Division, Department of Civil Engineering, College of Engineering,Trivandrum.