Effectiveness of Dowels in Concrete Pavement

Abstract

Dowels are located in transverse joints of Jointed Plain Concrete Pavements (JPCP) and they are used to provide load transfer between individual slabs, reduce faulting and improve performance. Dowels and the concrete itself are under the highest stress in the vicinity of joints; thus, in terms of pavement design, the joints are the weakest points of the whole structure. This study dealt with the drawbacks of JPCP with dowels. The evaluation was based on direct measurements on real airport and motorway pavements and highlights insufficient efficiency of load transfer and its possible causes. The authors present a successful outcome with validation by using the finite element method where high tensile stress values of the surrounding concrete were found.

Experimental Laboratory Testing on Behavior of Dowels in Concrete Pavements

“…Compressive stress on beams does not reach high values and there will be no concrete failure. Loaded edge deflection differences are negligible and comparable with measurement deflection on roads by falling weight deflectometers [34]. There was no significant displacement of the beam during the measurement.…”

“…Tensile stress values were experimentally determined in concrete for loading of 10 kN, which is the maximum force that traffic loading may be applied to a dowel. Since the tensile strength of concrete is lower (Table 1) than the measured values of tensile stress, concrete damage may occur in the area of the transversal joint particularly for 25 mm dowels [34]. It is recommended to increase the dowel diameter for JPCPs on highways (thickness 250-300 mm) to 30 mm while keeping the length of 500 mm and spacing of 250 mm in slow lanes, which are the most heavily loaded.…”

“…Findings from American tests were extended and beams with defective positions of dowels were tested. The selected variants were those that showed the highest stress in concrete by the theoretical calculation of the finite element method by ANSYS software and whose built-in dowel position allowed the installation of strain gauges [14,34].…”

“…Adhesive strain gauges were used for these tests. They are applied onto clean, dry and flat base of the concrete beam face in areas with the highest stress concentration, theoretically determined by the finite element method [34] 50 and 20 mm strain gauges were installed on the beam faces in the tensile (left and ride side) and the (above dowel) compression-stressed area (Figure 2b).…”

Comparison of pavement surface roughness characteristics of different wearing courses evaluated using 3D scanning and pendulum

“…Irregularities in the road surface in conjunction with changes in climatic characteristics [3][4][5] also affect airborne particulate matter (PM), according to research in articles [6,7]. The optimum texture value reduces the number of solids in the air.…”