Highway Research Record

II. PAVEMENT ENGINEERING AND PAVING MATERIALS
2. FLEXIBLE PAVEMENT
COMPLETED PROJECTS
Field Trials on Cationic Bitumen Emulsion for Optimisation of Binder Quantity in Bituminous Surfacings on NH-2 Near Agra

Duration: January 1998 to September 2004
Central Road Research Institute, New Delhi (R)

Present Status & Progress

Completed

Findings/Conclusions

(i) Construction of roads with specifications of Mix Seal Surfacings, Premix Carpet and Two Coat Surface Dressing using bitumen     emulsion is possible
(ii) Construction of roads for Mix Seal Surfacing and Premix Carpet with bitumen emulsion is possible by using concrete mixer
(iii) Lower binder content in MSS, PMC and TCSD is observed for almost same level of serviceability
(iv) 10 % binder economy is achieved in MSS, PMC and TCSD
(v) The section of specification with Mix Seal Surfacing using bitumen emulsion performed better than section with      conventional bitumen
(vi) Premix carpet with 10 % less binder with emulsion performed satisfactorily
(vii) Two Coat Surface Dressing with emulsion performed better than PMC and MSS
(viii) Cracks propagation on overlay reduced when emulsion is used
(ix) The specification of PMC with emulsion has been drafted from the data.
(x) The use of bitumen emulsion as tack coat retards the development of reflective cracks on the overlays

Recommendations
(i) Construction of roads with emulsion based cold mix technology adopting specification close-graded premix carpet (Mix Seal     Surfacing), premix carpet and two coat surface dressing is feasible on high volume roads such as National Highways.
(ii) Tentative IRC specification of Premix carpet and Surface Dressing will be modified in accordance with available data base
(iii) Framing of the guidelines for design, construction and quality control for construction of roads with emulsion
(iv) Construction of roads with premix carpet and two coat surface dressing with cold mix technology using emulsion may be       beneficial for improving the rural roads as less machinery is required for construction, even in monsoon season.
(v) Rural road construction with cold mix technology may be considered for formulating guidelines & specifications.