The back bone of any country’s economy is an efficient transport system. Although there are various modes of transportation which include rail, air and oceanic – road transportation is the most extensively used mode of transport. Paved roads for wheeled traffic date back as far as 2200 BC in Babylonia [Jenkins 2015]. South Africa’s road network consists of a vast number of paved roads which is used to transport goods for various industries and for day-to-day commuting to and from home, work, school and so forth. And therefore it is essential that a country’s road network is optimally designed and well maintained in order to maximize the productivity of its economy.
The principles incorporated into the design of low volume roads primarily focuses …show more content…
The most famous road test is the ASSHO Road Test which was conducted between 1956 and 1958 in Ottawa, Illinois. The test resulted in the development of the AASHO Design Procedure. The aim of the AASHO Road Test was to establish the relationships between pavement performance, pavement thickness and traffic loading for both flexible and rigid pavements.
The test consisted of six two-lane loops (Figure 2). The first loop was not subject any traffic loading but was used investigate the climatic, environmental and subgrade effects. However, the investigations were never carried out. The remaining five loops were subjected to frequent loading by vehicle of varying load types and weight (Figure 3). The layer thickness within each loop was varied in order to establish the relationships between pavement thickness and traffic …show more content…
The aim of this design method is to effectively predict the performance and response of a pavement under particular conditions. Flexible pavements structures comprise of more than one layer of different materials placed on a prepared subgrade. This type of pavement structure is known as an elastic layered system. This means that when a load is applied to the pavement the pavement will deform, but as soon as the load is removed the pavement will return to its original shape. However, at a certain point, the pavement will no longer be able to return to its original shape and as a result permanent deformation will occur in the form of rutting or