Response of Permeable Pavement under Wheel Truck to Rainfall Runoff and its Effects (Laboratory Model)

¹ Building and Construction Engineering Department, University of Technology, Baghdad, Iraq
² University of Al-Qadisyah, Dywanyah, Iraq

^a* Corresponding author aqeeladili@hotmail.com
^b 40323@uotechnology.edu.iq
^c eng.osama@yahoo.com

Abstract

Good water drainage from different sources is one of the most important factors that must be considered when designing subways and highways. The research aims to study and analyze the effect of heavy, medium, and low rainfall, select suitable materials to drain rainwater from the surface and vertical drains, and evaluate the rutting that appeared on the compacted surface asphalt layer. The methodology of this research includes the laboratory model (prototype model). A laboratory model consisting of typical structure layers of flexible pavement was used in this research with a 2% slope for degradations and changes in the volumetric properties and permeability of the surface and binder layers of the highway section. A wheel truck was manufactured and used for a continuous go-and-forth with the influence of three different rain intensities to identify and simulate the actual situation of highways and roads. The rainfall duration of 30 mm/min rainfall intensity was 90 minutes, and the rain intensity of 60 mm/min had a rainfall duration of 60 minutes. For the rainfall intensity of 90 mm/min, the time of rainfall was equal to 30 minutes. The results obtained from the laboratory simulation model (box model) indicated that the average quantity of infiltrated water produced by the 30mm/min rainfall intensity in the pavement structure is 36.4 % greater than the average infiltration of this water from the 60mm/min intensity and 52% higher than the 90mm/min intensity of rain. The time of surface drainage ending and the ending time of vertical drainage increases when the rain duration is long, even if the rain intensity is low. The rut depth appeared after 2816 wheel load repetitions to increase this depth by 96% after 127 days of load passage under three different rainfall intensities of a different time. The tensile strength was significantly reduced by 17.25%. The TSR values indicate that the mixtures of the surface and binder layers have good resistance to moisture damage.