Effect of Environmental Factors on Flexible Pavement Performance Modeling

A need has been felt by the various implementing organizations to develop an intelligent pavement performance model that can prioritize pavement maintenance and rehabilitation works, as this involves cost economics. Such models can forecast the pavement remaining service life and pavement rehabilitation needs. The flexible pavement deterioration models involve the complex interaction between vehicles and the environment, and the structure and surface of the pavement. The road deterioration models predict the deterioration of the pavement over time and under varying environmental conditions, which, generally, is manifested in various kinds of distresses. Each mode of distress develops and progresses at different rates in differing environment scenarios. Performance models relating the pavement material properties to various environmental factors are analyzed and developed by various researchers. A review of the literature related to the pavement performance prediction models indicates 'remaining age of the pavement' in terms of equivalent single axle load (ESAL) is the most significant predictor of serviceability. The modulus of elasticity and resilient modulus of the pavement materials, expressed in terms of various environmental factors like moisture content and temperature play only a secondary role in forecasting performance of pavements. But most of these models are found applicable to a particular set of traffic and environment conditions, thus highlighting the need for models that can work in varied conditions satisfactorily. The paper presents a detailed review of the effects of various environmental factors on pavement performance. Limitations and gaps are identified in the present knowledge of such models.