Effect of Mix Parameters Performance and Design of Cold Mix

Abstract

This project describes laboratory experiments and presents results for the performances of cold-mix, cold-lay emulsion mixtures. The main objective of the experiments was to evaluate and improve the properties of the cold mixtures. The mixture properties evaluated were: volumetric properties, indirect tensile stiffness modulus (ITSM), repeated load axial creep and fatigue. These properties were compared with conventional hot asphalt mixtures not containing any waste/recycled materials. To optimize the performances of the mixtures, a target of ITSM value of 2000 MPa was selected. At full curing conditions, the stiffness of the cold mixes was found to be very similar to that of hot mixtures of the same penetration grade base bitumen (100 pen). Test results also show that the addition of 1–2% cement significantly improved the mechanical performance of the mixes and significantly accelerated their strength gain. The fatigue behavior of the cold mixes that incorporated cement was comparable with that of the hot mixtures.

There is an increasing trend for using cold mix design with bitumen emulsion all over the world because of several advantages such as elimination of heating of binder and aggregate while producing mixes, this helps in protection of environment and energy conservation. In the present study, the main objective is to study the behavior and effect of pre compaction curing on grade-2 semi dense bituminous concrete (SDBC-2) mix using bituminous emulsions treated mixtures (BETM) by Modified Marshall Method of mix design. The specimen were prepared with and without filler. Comparison was made in terms of dry and wet Marshall Stability, Marshall Flow, Volumetric properties and Indirect Tensile Strength (ITS) on Modified Marshall specimen prepared by cold mix method for SDBC-2 mix. In the present investigation it was found that for mixes with and without filler the Volumetric properties, dry and wet Marshall Stability, Marshall Flow and ITS. Based on this present study it has been found that mix with cement and hydrated lime as filler each 2% both showed better results compared to mix with no filler. It has been seen that mix with 2% cement as filler showed better results compared to hydrated lime and there was no much difference in the properties for six and eight days cured specimen and hence could be concluded that six days curing period can be taken as optimum.