Air emission pollutants of different partial depth concrete bridge deck repair techniques: a comparative study

ABSTRACT Bridges are one of the main components of highway networks with intensive impacts in terms of air emissions. Therefore, an environmental assessment is essential for the bridge life cycle phases including design, construction, usage and maintenance, and lastly end of life. Most of the existing studies have focused on the material and construction phase while less attention has been given to the use and maintenance phase; notwithstanding the rapid increasing rate of bridge rehabilitation activities. This paper focuses on the bridge maintenance phase and represents a comparative environmental case study. The purpose of this paper is to compare different partial-depth concrete removal techniques from an environmental perspective, particularly the environmental effects on air quality. The paper compares the pollutant emissions of four common techniques: chipping, sawing and chipping, milling, and water-blasting. Two environmental data models are used, GREET and MOVES, and five air pollutants are considered which are CO2, CO, NOx, SO2, and PM10. The results indicate that chipping produces the least amount of pollutant emissions while milling emits the highest amount of air emissions. Additionally, there is a proportional relationship between the utilization time of the removal method and the amount of the released emissions of the method.