Construction and Evaluation of Low-Volume Roads Incorporating Emulsion Treated Base Layers: Fid-Bau Portal

Construction and Evaluation of Low-Volume Roads Incorporating Emulsion Treated Base Layers

Andrews, Jithin Kurian / Radhakrishnan, Vishnu / Koshy, Reebu Zachariah / Prasad, C. S. R. K.

Emulsion treated base (ETB) is a cold mix base layer stabilization technique in which virgin aggregates or recycled aggregates are treated with slow-setting bituminous emulsion. ETB in low-volume roads (LVR) can act as a stabilized base layer, which could replace the granular base layer. However, not many projects are coming up with ETB due to the absence of appropriate construction guidelines and pavement design catalogues for LVR incorporating ETB. In the present study, test sections were constructed on a LVR with six different combinations of ETB, and moduli values were back-calculated from the deflection data collected using falling weight deflectometer. Moduli of ETB layers were back-calculated using KGPBACK software, and the critical pavement responses were evaluated using IITPAVE software. Design catalogues were developed based on mechanistic empirical design principles, considering the back-calculated moduli of ETB, and was compared with the thicknesses required in case of pavements incorporating conventional granular base layers. It was observed that the application of ETB in LVR can reduce the need for virgin aggregates in base layers by 35–40%. The study proposes relationship between indirect tensile strength and back-calculated moduli of ETB, so that the designer can appropriately select the moduli values corresponding to the design mix, and evaluate the required pavement thicknesses. Based on the calculated equivalent layer thickness of ETB, it was concluded that 1 unit of ETB layer was equivalent to 1.4–1.7 times the conventional granular base layer, depending upon the mix constituents.