A Review of Studying the Relationship of Traffic Stream Characteristics and Noise Intensity with Flexible Pavement Surface Condition

In general, roads are a very important infrastructure to facilitate people’s access to their social and economic activities, so knowing the things that affect the efficiency of these roads is very important and how to maintain them. One of the aims of this research is to shed light on previous studies that showed the relationship between traffic characteristics and noise intensity on the condition of the breakable Pavement. The results of previous studies show that flexible Pavement has 19 potential failures and how to address them. There is a relationship between the characteristics of traffic flow and failures that occur in flexible paving. It is also possible to calculate the road condition by knowing the types of faults on the road using several roads or by using specific formulas to calculate the road condition index. There are relationships between the road condition index, the vehicles’ speed, and the models that link Noise to speed. And that most of the relationships that were used to calculate the elastic pavement condition index and its relationship to the movement characteristics are statistical relationships using ANOVA, recreation, and R2

Modelling Of Crack Propagation in Flexible Pavement Using X-FEM Method

A research aim was to achieve a finite element model for predictive pavement cracking implementing ABAQUS software ver.6.12.1. A simulation model for pavement structure was implemented to analyze the propagation of cracks within flexible pavement. The X-FEM method adopted in this research based on the functions of interpolation that can characterize the displacements near the crack zone, initial crack was defined at the bottom of asphalt layer. The estimated results illustrated that X-FEM was efficient for the simulation of cracks in pavement structures without the need for re meshing during crack propagation evolution process. Finally, inclusive simulation results probed the considerable effect for improvement of bonding layers to enhance the service life of pavement in terms of decreasing the rate of crack propagation. The crack was propagated upwards from depth end of asphalt layer to pavement surface and deviated from center of applied pressure with an inclination of almost 300 in the third upper zone of asphalt layer while the pre-crack point was always located in the bottom of asphalt layer in pavement model because of the different characteristics of their bonding bases. In the crack zone the permanent deformation was increased gradually from the crack edge along vertical direction of crack spread due to tensile stresses concentration at the crack zone. The action of horizontal and vertical stresses affect crack propagation and growth vertically to the direction of higher horizontal tensile stresses, and along direction of higher compression vertical stresses.

Framework for Design of Sustainable Flexible Pavement

The conventional methodologies for the design of flexible pavements are not adequate in providing solutions that meet the diverse sustainability challenges. Therefore, developing new methodologies and frameworks for the design of flexible pavement has become a priority for most highway agencies. On the other hand, there is no sound sustainable flexible pavement framework at the design phase that considers the key engineering performance, environmental impact, and economic benefits of sustainability metrics. Hence, premature failure of flexible pavements has become a common problem leading to a growing demand for sustainable pavement. Pavement engineers need to have access to tools that permit them to design flexible pavements capable of providing sustainable solutions under various complex scenarios and uncertainties. Hence, the objective of this study was to develop a resilience analysis framework, probabilistic life cycle assessment (PLCA) framework, and probabilistic life cycle cost analysis (LCCA) framework as the pillars of sustainability. These frameworks were used to develop a single sustainable flexible pavement design framework. The developed framework enables highway agencies to effectively quantify the lifetime sustainability performance of flexible pavements during the design phase in terms of resilience, environmental sustainability, and economic sustainability; and it allows to select the optimum design by comparing alternative design options. The framework will enhance the durability of flexible pavement projects by minimizing the cost, operational disturbance, environmental impact, and supporting the design. Many countries, especially those that fully dependent on the road network as the primary transportation route, may benefit from the sustainability-based road network design, which could ensure dependable market accessibility. The resilience of such a road network may reduce the cost of business activities by minimizing the interruption in surface transportation due to the functional and structural failures resulting from extreme events.

Asphaltic Concrete Pavement Strength and the Impact of Rainfall

Studies have shown that moisture impacts on the strength of flexible pavement surface of asphaltic concrete. Several investigations and relevant researches treated the effect of subsurface and surface water sources, on the durability of flexible pavements. This study is focused on the surface water sources, as a result of precipitation (rainfall), on the surface of flexible pavements. To conduct this experiment, the considerations made include (i) the continuous exposure of the pavement surface to annual rainfall (ii) application of pavement exposure to moisture in the field. This study considered the amount of rainfall each day, as the duration (age) of pavement exposure to moisture (being under water during rainfall). For the purpose of this experiment, the Owerri to Onitsha about 90km of dual carriage way in south east of Nigeria, was considered. This is a flexible pavement that traverses through the rain forest belt, characterized with high amount of annual rainfall values. Flexible pavement specimens from this road were obtained, cleaned and immersed in water after weighing, to keep vital records of the necessary parameters, before further tests at 7days intervals. Values of strength obtained after days in water, that approximated to the appropriate field situation of exposure to rainfall, showed a consistent loss of strength, from the crushing strength results.