Optimization of Structure Parameters of Airfield Jointed Concrete Pavements under Temperature Gradient and Aircraft Loads

Abstract

Daily changing temperature causes significant thermal stress in concrete pavement. Tensile stress obtained can exceed flexural tensile strength when the concrete slabs are subjected to large temperature gradient and traffic loads, resulting in pavement damages. In this paper, maximum tensile stresses in concrete slabs with different slab sizes, thicknesses, and length to width (L/W) ratios were investigated by using the finite element (FE) method. The important parameters in the design of concrete pavement are the flexural tensile strength and the fatigue limit. By analyzing the comparison results between the maximum tensile stress and the fatigue limit, the optimum slab size and the critical thickness were determined. The results indicate that the maximum tensile stress obtained is higher for larger slab size with thin thickness. Furthermore, to reduce cutting work and the amount of dowel bars, the optimum slab sizes of the regional airport concrete pavement are recommended as 4 m × 4 m to 6 m × 6 m. The critical thicknesses of 4 m × 4 m slab and 6 m × 6 m slab are determined as 28.2 cm and 34.7 cm, respectively, based on the most unfavorable coupling between positive and negative temperature gradients and the Boeing 737–800 aircraft load. Moreover, the maximum tensile stress increases as the L/W ratio increases. When the slab length is less than 6 m, it is better to use square slab in airport jointed concrete pavement (JCP).

Dynamic Response Analysis of JPCP with Different Roughness Levels under Moving Axle Load Using a Numerical Methodology

“…The finite element method is used to calculate the stress generated in JPCP, and dynamic analysis is conducted to calculate the dynamic response of JPCP, following the motion equation as shown in Equation (16). It has been shown that second-order elements in the finite element analysis can significantly reduce the number of elements along the thickness of the slab [27]. Therefore, three layers of C3D20R elements are used in Slab2 with a horizontal dimension of 7 cm, two layers of C3D20R elements are used for Slab1 and Slab3 with a greater horizontal dimension, and three layers of C3D8R elements are used for the base and the subbase with a horizontal dimension of 10 cm.…”

A Fast and Non-Destructive Prediction Model for Remaining Life of Rigid Pavement with or without Asphalt Overlay

“…where, E c is the concrete layer bending modulus; ν c is the Poisson ratio of concrete, which is a constant during the elastic deformation phase of the material, and ν c is usually 0.15 of the cement concrete. The driving load fatigue stress generated at the critical load position in a rigid concrete slab, σ pr in Equation (7), is deduced and calculated as Equation (11). It reflects the mechanical equilibrium state of the pavement; that is, the flexural tensile strength of the cement concrete is exactly equal to the load-temperature coupling stress of the bottom of the rigid PCC pavement.…”

“…The concept of the remaining life of a pavement is based on the premise of directly repairing particular road damage or designing an asphalt overlay to cover the original surface defects [5,6]. Remaining life represents the rest of valid service life until a failure is reached in the PCC pavement as a result of exposure to traffic and environmental forces [7]. The concept of remaining life is helpful for making optimal use of the capacity for in-service pavement repair and facilitating decision-making for reconstruction or rehabilitation with limited existing resources [8,9].…”