Natural gravel-recycled aggregate concrete applied in rural highway pavement: Material properties and life cycle assessment

Natural gravel-recycled aggregate concrete (NG-RAC) has favorable prospects in rural highway pavement due to instant acceptance and tremendous need. This paper studies the material properties (including mechanical properties and frost resistance durability) and carries out a life cycle assessment (LCA) based on an actual en-gineering case. It can be found that, although the overall performance of NG-RAC is somewhat lower than those of natural aggregate concrete (NAC) or crushed stone-recycled aggregate concrete (CS-RAC), it meets the re-quirements for low-grade pavements. Compared with the pavement constructed with CS-NAC and CS-RAC, the results show that, carbon emissions are reduced by about 48.7% and 39.1% for the practical NG-RAC pavement, respectively. Besides, the sensitivity analysis of transport distance was conducted to estimate the limit trans-portation distance ratios of RCA/NCA and NG/CS. By quantitative analysis, it can be concluded that rural highway pavement built with NG-RAC will produce considerable environmental and ecological benefits, including energy-saving, carbon emission reduction, environmental cost lowering and land conservation.