Impact Of Traffic Characteristics and Pavement Surface Condition on Noise Level for Rigid Pavement

The proper design of a road’s surface layer can result in pavements that are not only better in terms of ride comfort and safety, but also in terms of noise reduction. The use of low-noise pavements may be an effective measure to reduce the acoustic pollution generated by road traffic This study aims to consider the effect of changed pavement features on the noise level. Tire/pavement noise is a major contributor to traffic noise at highway speeds. The effects of pavement properties, including air-void content, gradation properties, roughness, texture, pavement surface condition are major contributors to traffic noise at highway speeds. As the overall texture and IRI, increase noise levels. The results showed that greater air void content decreases the level of high-frequency noise.

Research on Mechanical Response of Pavement Structure to Differential Settlement of Subgrade on Highway Widening

Based on the widening project of Ri-Lan highway in China, the finite element model is established by PLAXIS. By applying differential settlement at the bottom of the pavement, the mechanical response of the pavement structure is analysed. Finally, the differential settlement control standard indicated by crack strength is proposed. The results show that, under the effect of differential settlement, within about 4 cm of old pavement surface and upper base bear tensile stress, the base first reaches the failure strength. Under 4 cm of the old pavement surface, the subbase first reaches the failure strength. The differential settlement control standard of the pavement structure is determined by the splitting strength of the material, and we, respectively, control the differential settlement of less than 23.4 mm, where the corresponding cross-slope rate is 0.33%, and below 75.2 mm, where the corresponding cross-slope rate is 0.54%. It could support practical engineering applications.

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.

Exploring Implicit Relationships between Pavement Surface Friction and Vehicle Crash Severity Using Interpretable Extreme Gradient Boosting Method

Pavement friction has been identified as crucial in traffic safety. Since the Highway Safety Manual prediction algorithm is often based on crash frequency, the crash severity distribution might be assumed unchanged before and after the countermeasure. However, pavement surface treatments can improve the friction to different levels, by which crash severity outcomes may vary greatly. To explore the implicit effects of pavement friction on vehicle crash severity, this paper first validates the extreme gradient boosting model performance and then the Shapley additive explanations interaction values are employed to interpret individual features and the nonlinear interactions among predictors. Under various scenarios, the XGBoost output probability is utilized to convert into dynamic crash severity distributions. Results also indicate that friction becomes more significant when the friction number is less than 38, and immediate corrective actions are needed when the friction number is below 20.

Evaluating the Friction Characteristics of Pavement Surface for Major Arterial Road

The performance of the pavement in terms of vehicle safety and tire wear is affected by the friction behavior of the pavement. To highlight the main characteristics that affect the production of better friction resistance of the pavement surface in this work. The micro-texture and macro-texture of the asphalt surface of Baghdad Airport highway were studied using two methods: (sand patch method and the British pendulum test). The sand patch was examined by drawing sand grains of a specific volume, while the micro-texture was analyzed using a BPT under dry and wet surface conditions. All data obtained from the two examinations were analyzed and modelled statistically using SPSS 25 software. Results show that skid resistance of pavement surface increase with the increase of MTD, this increase may be due to the increase of coarse aggregate which lead to increase the roughness of the pavement surface, this increase ranged between (96 - 91%). MTD decreases with the increase of traffic flow due to the friction between the road surface and the vehicle tires leading to increase of smoothness of the road surface. This is mean that MTD is highly affected by the traffic flow and this effectiveness ranged between (84-97%). Skid resistance also is highly affected by the traffic flow with an effectiveness ranged between (81-94%) for both pavement conditions. According to the regression analysis for friction and other parameters, it can be concluded that surface friction values are highly affected by cumulative traffic (asphalt mix deterioration) over time. Doi: 10.28991/cej-2021-03091775 Full Text: PDF

Effects of Albedo and Thermal Inertia on Pavement Surface Temperatures with Convective Boundary Conditions—A CFD Study

The urban heat island (UHI) effect increases the ambient temperatures in cities and alters the energy budget of building materials. Urban surfaces such as pavements and roofs absorb solar heat and re-emit it back into the atmosphere, contributing towards the UHI effect. Over the past few decades, researchers have identified albedo and thermal inertia as two of the most significant thermal properties that influence pavement surface temperatures under a given solar load. However, published data for comparisons of albedo and thermal inertia are currently inadequate. This work focuses on asphalt and concrete as two important materials used in the construction of pavements. Computational fluid dynamics (CFD) analyses are performed on asphalt and concrete pavements with the same dimensions and under the same ambient conditions. Under given conditions, the pavement top surface temperature is evaluated with varying albedo and thermal inertia values. The results show that the asphalt surface temperatures are consistently higher than the concrete surface temperatures. Surface temperatures under solar load reduce with increasing albedo and thermal inertia values for both asphalt and concrete pavements. The CFD results show that increasing the albedo is more effective in reducing pavement surface temperatures than increasing the thermal inertia.