Pavements

Pavement deterioration

Pavement deterioration is very complex. It involves structural fatigue as well as functional distresses. It results from the interaction between traffic, climate, material and time. Deterioration is the term used to represent the change in pavement performance overtime. The ability of the road to satisfy the demands of traffic and environment over its design life is referred to as performance. Due to the great complexity of the road deterioration process, performance models are the best approximate predictors of expected conditions.  

It is necessary to provide a good road network for the development of any country. India has the second largest highway and road networks system on the world. The total length of roads in the country exceeds 3.01 million kilometers. There is a great need for the effective and efficient management and maintenance of the road network. The funding available for periodic maintenance and management system is limited. In order to determine the most economical strategies, most essential input is development of deterioration models for structural and functional conditions of flexible pavements. Pavement performance is a function of its relative ability to serve traffic over a period of time (Highway Research Board,1962).

Cool pavement methods

 Cool pavements refer to a range of established and emerging materials. These pavement technologies tend to store less heat and may have lower surface temperatures compared with conventional products. They can help address the problem of urban heat islands, which result in part from the increased temperatures of paved surfaces in a city or suburb. Communities are exploring these pavements as part of their heat island reduction efforts. Conventional pavements in the United States are impervious concrete and asphalt, which can reach peak summertime surface temperatures of 120–150°F (48–67°C).2 These surfaces can transfer heat downward to be stored in the pavement subsurface, where it is re-released as heat at night. The warmer daytime surface temperatures also can heat stormwater as it runs off the pavement into local waterways. These effects contribute to urban heat islands (especially at nighttime) and impair water quality. 

                                                                   How It Works

 Understanding how cool pavements work requires knowing how solar energy heats pavements and how pavement influences the air above it. Properties such as solar energy, solar reflectance, material heat capacities, surface roughness, heat transfer rates, thermal emittance, and permeability affect pavement temperatures.

Here are some examples