Sensitivity Analysis of AASHTO Design Method and Maintenance of Flexible Pavements - Research Paper Example

Over the years, pavement design did not consider basic mandatory factors such as traffic loads, soil type and strength, and a possible increment in the volume of traffic. In effect, poor design methods in the past resulted in non-durable pavements with short lifespan.Such problems led to intensive research on the structural properties of soils in order to find a relationship with pavement performance of the subgrade layer. AASHTO and other bodies were then formed to alleviate such problems and by carrying out road tests in order to come up with a durable pavement.

Therefore, AASHTO put into consideration the effect of load and the quality of materials in pavement design among other requirements. The research paper aims to intensively discuss the AASHTO pavement design by carrying out a sensitivity analysis in mechanistic-empirical design technique for flexible pavements. Other paradigms for designing pavements such as CBR and IRC are also considered.Several roads have adopted the use of the AASHTO method in designs of flexible pavements across American roads.

The design of roads has been basically based on pavement thickness, climatic conditions, and materials. AASHTO has tremendously carried out research on various parameters affecting the design of pavements and design formula which was based on the performance of the test sample section. AASHTO tests were carried out to establish some of the basic design factors such as ultimate strength and axle load(Shahji, 2002). The road tests validate that heavy loads are drastically larger than the damage caused by the less heavy loads.

The aim of the road test is to achieve the equivalency of load which results in the outcome of the axle loads on pavements in terms of an equivalent single axle load (AASHTO, 1998). The standard axle load is 18klb which is used as a reference point for other loads of the vehicles.In essence, flexible pavements refer to all group of pavements that are not built using cement, concrete or concrete blocks.