The use of deflection bowl parameters to represent the carrying capacity of pavement structures

Evaluation of pavement structure has to be carried out periodically to monitor the carrying capacity of the pavement to withstand against loads. The evaluation using backcalculation algorithm to determine layer moduli is the most ideal manner in revealing the residual capacity of the pavement. Due to limited human resources, some agencies in developing countries rely on the use of pavement functional conditions to predict roughly layer structural capacity, however, this leads to unsatisfactorily and inaccurate results. To overcome this, deflection bowl method can be proposed to estimate an indication of the structural capacity of the pavement. The study aimed to evaluate the suitability of the deflection bowl parameter to represent the structure. To do so, an examination of the similarities of the pattern of the deflection bowl parameters and elastic moduli of the pavement layers along selected road segments was conducted, and statistical analysis was presented to justify the results. The results showed that deflection bowl parameters have a strong relationship with the layered moduli. The overlay above the existing surface layer that may consist of more than 1 layer up to 205 mm or 8 in. thickness also can be represented by the maximum deflection parameter. (paper)