Investigation on the Cooling and Evaporation Behavior of Semi-Flexible Water Retaining Pavement based on Laboratory Test and Thermal-Mass Coupling Analysis

Abstract

The Semi-Flexible Water Retaining Pavement (SFWRP) has the capability to cool down the temperature of the road surface through its evaporation behavior, including absorbing and evaporating water; this is an efficient approach to relieve the heat island effect in a big city. The temperature feedback from different material surface were investigated in this paper in the same test condition, it has been proved that the SFWRP material can remarkably cool down the temperature of the road surface. The mechanism of the material evaporation behavior, including flux calculation formula of the water vapor inside the air void, were studied by inter-phase continuous function, in which the structural properties of the SFWRP material was taken into account. Furthermore, the function calculating the evaporation of the water vapor was then developed in this research through heat and mass transfer analogy. Besides, the calculating results can be captured by the self-coding program in Finite Element Modeling (FEM) for water evaporation simulation. Also, the results of laboratory tests were adopted to validate the calculating model. Finally, it has been proved that the mortar was recommended to be used in semi-flexible water retaining pavement to serve as material with permeable and water retaining property, and the semi-flexible water retaining pavement material is recommended to applied in the surface layer of the permeable pavement.

Investigation of the Relationship between Rainfall and Fatal Crashes in Texas, 1994–2018

“…Roadway fatalities, injuries, and crashes can be substantially reduced when new vehicle safety technologies, such as available automatic emergency braking, lane departure warning, blind spot warning, and pedestrian detection technologies become more common. Actually, some studies expect the wide adoption of these technologies to cut crash fatalities by about 50% (e.g., Wang, 2019) [61]. Measures such as more supervised driving time in teen driver education programs and considering road design characteristics may significantly decrease crashes committed by young drivers.…”

“…The correlation test reveals a negative correlation of −0.66 between monthly fatal rain-related crashes and rainfall averages for the month. This can be explained by the effect of temperature, with evaporation cancelling the effect of rainfall during the summer (e.g., [48]). Moreover, cooling of hot road surfaces Figure 12 shows the monthly distribution of the proportion of rain-related fatal crashes to statewide average monthly precipitation temperature of the study period.…”

Influential Factors and Evaluation Methods of the Performance of Grouted Semi-Flexible Pavement (GSP)—A Review

“…For example, water-retaining material is mixed into grouting material to produce water-retaining GSP. This pavement can cool down 8 • C-10 • C for eight hours for the surrounding area by evaporating the water absorbed from rain, while it maintains a high anti-rutting performance [91,92]. Phasechange material (PCM) is also added into GSP to adjust the ambient temperature.…”

SSD Analyze for the Assessment of Long Term Thermal Effect of Urbanization on the Izmir City’s Local Climate Change

“…So, in this case, the water is used for absorbing the heat from industrial building roofs and then for removing it through existing rainwater drainage systems on the roofs. Same approach can be applied to the wide asphalt roads such as highways to remove heat from the road surface (Dong et al, 2019) and then drainage it through the existing road side drainage system. As a side benefit, the heated water can be used for different purposes in the cities as well.…”