| Green low-carbon development has become the trend of the times.The 20 th CPC National Congress proposed to plan for development at the height of harmonious coexistence between human and nature.Green development has become the due meaning of development in the field of transportation construction.With the advantage of 100%recycling of waste asphalt mixture,hot in-place recycling technology(HIR)has become one of the widely used technologies in asphalt pavement maintenance.But the environmental impact cannot be underestimated.At present,HIR has gradually changed from traditional process to clean process,but without a universal evaluation standard.In recent years,the national has issued green construction standards for the industry and highway construction.But the green construction standards for highway maintenance have not yet been formed.Therefore,it’s of great significance to establish an evaluation system adapted to HIR.This thesis relies on Guangdong Province "Highway asphalt pavement clean HIR specification research" project,as well as the Chinese Highway Society to organize the "Highway asphalt pavement clean HIR guide" project,with the support of several units.We have conducted follow-up research on HIR construction in many provinces and cities in China,collected a large number of field data,grasped the situation of HIR construction in a relatively comprehensive way.And built an evaluation index system and evaluation model for HIR green construction,aiming at evaluating the green level of HIR construction.Firstly,this thesis refers to the current situation of green construction and green road evaluation research at home and abroad.Based on the traditional HIR and clean HIR,green construction evaluation is introduced into the HIR evaluation.The concept and evaluation boundary of green construction for HIR are proposed.According to the evaluation needs,select the appropriate evaluation method by comparison.Secondly,based on the survey data,the green construction factors of HIR are studied from three aspects: quality,environment and safety.The temperature is the key factor affecting the quality,the site boundary temperature is an important indicator to ensure safety.The environmental factors include carbon emissions,asphalt fume and its constituents such as PAHs,TSP,SOx and NOx gases,etc.And analyze their intrinsic connection with the construction link.According to the principle of operability,the atmospheric transmittance is used to reflect the trend of asphalt fumes.The nonparametric test method Spearman rank correlation coefficient is adopted for correlation test.Based on the study of the existing green highway evaluation index system and the evaluation index system of HIR,the evaluation index library of HIR green construction is constructed.According to the characteristics of HIR construction and the evaluation boundary,5 primary indicators and 18 secondary indicators are initially screened and summarized.The Delphi and CVR were used to determine the first-level indicators:technical utility,environmental protection,safety and technological innovation.Quantitative indicators are quantified according to national standards and objective data,and qualitative indicators are quantified using expert scoring method to ensure the reliability of indicator assignment.The combined ANP-CRITIC weighting is adopted to determine the indicator weight and weaken the subjective or objective unilateral influence.The cloud model is selected as the HIR green construction evaluation model to solve the uncertainty of the index and the fuzziness of the grade.The green grade is determined according to the cloud similarity.Finally,taking Xinzhou North Expressway Maintenance Project in Shanxi Province as an empirical case.The representative of traditional HIR is the German Wittgen RX-4500 unit.The representative of clean HIR is the domestic JP-6000 unit.Both are used as evaluation objects to evaluate the green construction of HIR and to verify the feasibility and scientific of the evaluation index system and model. |
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