TY - JOUR
T1 - Environmental impact assessment of pavement road bases with reuse and recycling strategies
T2 - A comparative study on geopolymer stabilized macadam and conventional alternatives
AU - Zhang, Yiyuan
AU - Gong, Hongren
AU - Jiang, Xi
AU - Lv, Xiuyuan
AU - Xiao, Rui
AU - Huang, Baoshan
N1 - Publisher Copyright:
© 2021
PY - 2021/4
Y1 - 2021/4
N2 - Geopolymer is a potential solution to the high carbon emissions caused by cement. Life cycle assessment (LCA) methodology was applied in this study to evaluate the environmental impacts of pavement road bases with reuse and recycling strategies. We considered four types of stabilized road base materials to evaluate environmental impacts: waste glass-fly ash based geopolymer stabilized macadam (WFAG), fly ash based geopolymer stabilized macadam (FAG), cement stabilized macadam (CS) and cement-fly ash stabilized macadam (CFAS). Two alkaline activators were used to synthesize geopolymer road base materials. The results showed that the application of geopolymer road bases reduced global warming (GWP) significantly. Comparing with CS, the GWP of WFAG and FAG declined by 17.9% CO2, eq per function unit. The combined alkaline activator consisting of sodium hydroxide (NaOH) and water glass had lower environmental impacts compared to the one with pure NaOH alkaline activator. The ozone layer depletion (ODP) of geopolymer stabilized road bases using pure NaOH solution was an order of magnitude higher than the ODP using the combined alkaline activator consisting of NaOH and water glass. For other indicators except GWP, the environmental impacts of conventional road bases were lower than geopolymer stabilized road bases, indicating a pollution transfer during application of geopolymer road bases.
AB - Geopolymer is a potential solution to the high carbon emissions caused by cement. Life cycle assessment (LCA) methodology was applied in this study to evaluate the environmental impacts of pavement road bases with reuse and recycling strategies. We considered four types of stabilized road base materials to evaluate environmental impacts: waste glass-fly ash based geopolymer stabilized macadam (WFAG), fly ash based geopolymer stabilized macadam (FAG), cement stabilized macadam (CS) and cement-fly ash stabilized macadam (CFAS). Two alkaline activators were used to synthesize geopolymer road base materials. The results showed that the application of geopolymer road bases reduced global warming (GWP) significantly. Comparing with CS, the GWP of WFAG and FAG declined by 17.9% CO2, eq per function unit. The combined alkaline activator consisting of sodium hydroxide (NaOH) and water glass had lower environmental impacts compared to the one with pure NaOH alkaline activator. The ozone layer depletion (ODP) of geopolymer stabilized road bases using pure NaOH solution was an order of magnitude higher than the ODP using the combined alkaline activator consisting of NaOH and water glass. For other indicators except GWP, the environmental impacts of conventional road bases were lower than geopolymer stabilized road bases, indicating a pollution transfer during application of geopolymer road bases.
KW - Geopolymer
KW - Life cycle assessment
KW - Pavement road bases
KW - Waste
UR - http://www.scopus.com/inward/record.url?scp=85101713130&partnerID=8YFLogxK
U2 - 10.1016/j.trd.2021.102749
DO - 10.1016/j.trd.2021.102749
M3 - Journal article
AN - SCOPUS:85101713130
SN - 1361-9209
VL - 93
JO - Transportation Research Part D: Transport and Environment
JF - Transportation Research Part D: Transport and Environment
M1 - 102749
ER -