A cradle-to-grave life cycle assessment and life cycle cost analysis of cold in-place recycling technology considering hybrid uncertainties

Cold in-place recycling (CIR) is gaining ground globally as a sustainable pavement rehabilitation technology. One of the effective parameters in the sustainable performance of CIR is the production method of polymer modified bitumen emulsion (PMBE). The impact of different PMBE production methods on the environmental burdens and economic costs of pavements constructed on CIR layer at low and high traffic levels were investigated in this study. To evaluate the environmental burdens and economic costs, life cycle assessment (LCA) and life cycle cost analysis (LCCA) were conducted using a comprehensive cradle-to-grave approach. The results of LCA and LCCA showed that the PMBE production method has impact on the environmental burdens and economic costs of pavements constructed on CIR layer. More precisely, the simultaneous use of PMBE produced by the post-blending method and Portland cement caused a reduction in global warming, acidification, ozone depletion, eutrophication, smog, and cumulative energy demand up to 10.8, 20.3, 3.1, 46.1, 23.5 and 5.6 % in low traffic level and 4.1, 8.7, 0.5, 31.9, 10.6 and 3.0 % in high traffic level, respectively. Additionally, economic costs were decreased by 29.4 and 16 % in low and high traffic levels, respectively. • The production method of PMBE is effective on the LCA and LCCA of CIR pavement. • LCA and LCCA showed the advantages of PMBE production by Post-blending method. • Using CIR for low traffic volume has more environmental and economic benefits. • Sensitivity and uncertainty analyses were conducted to make an informed decision.