PURPOSES: Knowing the scope of deterioration of the concrete slab around spalling is important in determining the size of the partial-depth repair. The change in the material properties of the concrete slab, according to the severity of spalling and distance from spalling, is analyzed herein by performing non-destructive and destructive tests at the field and in the laboratory. METHODS: The test slabs were determined by finding spallings with high or medium severity. The relative elastic modulus was measured near the spalling, far from spalling, and around the slab center using an impact echo equipment. The core specimens were obtained at the measurement positions. An absorption test was performed for the core specimens, while the impact echo and dynamic modulus tests were performed for the upper and lower parts of the core specimens under dry or saturated conditions. A compressive strength test was also performed for the upper and lower parts of the core specimens. RESULTS : The absorption coefficient, relative elastic modulus, relative dynamic modulus, and relative compressive strength worsened as the measurement position became closer to the spalling distress and top of the slab. The worse material properties were measured for the spalling with a higher severity. The moisture condition of the specimens scarcely affected the material properties. CONCLUSIONS : The impact echo test results obtained at the field showed a high correlation with the results of the absorption, impact echo, dynamic modulus, and compressive strength tests performed in the laboratory. Accordingly, a quicker and a more convenient nondestructive soundness evaluation of concrete pavements is expected to be realized using the field impact echo test method.

PURPOSES : Almost every design method for airport concrete pavements considers only traffic loading and not environmental loading. This study proposes a mechanistic design method for airport concrete pavements, that considers both environmental and traffic loading simultaneously. METHODS: First, the environmental loading of concrete pavements in Korean airports was quantified. FEAFAA, a finite element analysis program for airport pavements, was used to calculate the maximum tensile stress (MTS) of the slab, caused by both environmental and traffic loadings. The factors that influence the MTS were identified via sensitivity analysis, and an MTS prediction model was developed using the statistical analysis program SPSS. The ratio of MTS to the tensile strength of slab was calculated using the prediction model. The fatigue model under the AC 150/5320-6E and AC 150/5320-6F standards of the FAA was corrected to make it suitable for the predicted stress-strength ratio. RESULTS : The MTS prediction model and corrected fatigue model were used to redesign the slab thickness and joint spacing of airport concrete pavements originally designed using the AC 150/5320-6D standard, which empirically considers traffic loading only. As a result, different slab thicknesses and joint spacings were redesigned with consideration for environmental loading, specifically the weather conditions of airports. . CONCLUSIONS: The slab thickness and joint spacing can be mechanistically designed at the same time, whereas previously, only the slab thickness was designed, and the joint spacing was determined empirically.