Performance of long term glass-grid test section in Warsaw

This paper presents the study that investigated the performance of the glass-grid reinforced trial pavement sections. Considered test section was constructed in 2001 in the city of Warsaw during the full-depth reconstruction. The section was sub-divided into two parts: one subsection had an installation of the glass-grid between asphalt sub-base and asphalt binder course, while the other subsection was the control pavement without the any reinforcement. Performance and effectiveness of the reinforcement was evaluated in in 4-year intervals between 2004 and 2012. The evaluation of data comprised the FWD maximum deflection comparison as well as deflection bowl geometry analysis. Additionally, the Traffic Speed Deflectometer (TSD) device was used to assess the pavement condition in 2013. The bowl geometry analysis was conducted using an unique approach in which the deflection bowl was subdivided into 3-point segments and an arch was circumscribed into each segment. Reinforced sections were characterized by statistically higher values of the arch radiuses than the unreinforced sections which could be considered as the measureable reinforcing effect of glass-grid on the pavement fatigue life. Maximum deflections growth in year-to-year comparison was higher on the unreinforced section as well as more deteriorations were observed on the unreinforced section. The TSD measurements were also compared between two subsections and analyzed in terms of the calculated deflections.