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Abstract: The dynamic modulus of an asphalt mixture is widely used as an important material property in mechanistic–empirical (ME) pavement design and analysis because it accounts temperature and time-dependent asphalt mixture modulus. The aim of this study is to evaluate the dynamic modulus of asphalt mixtures used in Korea and develop a predictive equation for Korea ME pavement design guide based on the results of dynamic modulus tests. Asphalt mixtures contained a granite aggregate with PG 58-22 and PG 64-22 asphalt binders were tested at five different temperatures (−10, 5, 21, 40, and 55°C) and six different loading frequencies (0.1, 0.5, 1, 5, 10, and 25Hz). A predictive equation was constructed based on the test data, and compared and verified between the measured and the predicted dynamic modulus. From the results, it was found that the predictive equation correlated well with the measured values. [Copyright &y& Elsevier]

• Innovative Pavement Distress Detection: This study introduces a pioneering approach utilizing an RGB-D camera and instance segmentation algorithm to detect and quantify pavement distress, offering a unique solution to a critical infrastructure challenge. • Accurate 3D Point Cloud Analysis: The method efficiently converts pixel data into 3D point clouds, enabling precise assessment of distress area and severity, enhancing reliability in pavement condition evaluation. • Optimized Data Acquisition Strategy: Through rigorous testing and simulation using high-density polystyrene foam, the study identifies an optimal data acquisition scheme, ensuring dependable results even under varying experimental conditions. • Severity-Dependent Error Reduction: Findings demonstrate that error rates in area and volume measurements decrease as distress severity increases, highlighting the method's capacity to provide more accurate assessments for severe pavement issues. • Cost-effective Maintenance Solution: This approach offers a low-cost, high-precision solution for pavement distress detection and maintenance, presenting significant potential benefits for infrastructure management and maintenance planning. This study presents an innovative and cost-effective approach for pavement distress detection and quantification using an RGB-D camera in conjunction with an instance segmentation algorithm. The proposed method employs the instance segmentation algorithm to acquire 2D coordinate information pertaining to the affected pixels and integrates the internal reference matrix and depth data from the depth camera to transform the 2D images of the distressed areas into 3D point cloud data, consequently enabling distress quantification. To assess the dependability of the proposed approach, high-density polystyrene foam was used to simulate potholes and cracks of the pavement. Data collection was conducted under varying experimental conditions to identify the optimal data collection scheme. Using the approach, potholes and cracks of varying severity were collected from both asphalt and cement concrete pavements. The outcomes of the study demonstrate that the proposed methodology is capable of accurately detecting and quantifying potholes on the pavement. Furthermore, the errors associated with both the calculated area and volume exhibit a gradual decrease with an increase in the severity of pavement distress. However, for cracks, the method yields a larger error in results, primarily due to the instance segmentation algorithm's imprecise segmentation of crack edge pixels, despite superior restoration of the planar contour of cracks. [ABSTRACT FROM AUTHOR]

For partial depth repair of airport concrete pavement, the thickness and physical properties of the materials used in the repair project are the prerequisite for the success of the repairing works. While under most actual constructions, these two factors are always regarded as the focus of the project, which leads to the re-damage of the repaired section once again. The repaired concrete pavement can be easily re-failed due to the incompatibility between the repair materials and the matrix concrete for their different characteristics in the aspect of thermal expansion and drying shrinkage. In general, the mechanistic model is used to calculate the interface stress by drying shrinkage and thermal expansion. However, the interface stiffness cannot be figured out by this way. In this study, the interface stress was calculated by the volume change of three kinds of repair materials which were Styrene Butadiene Rubber Concrete (SBR), Polymer Concrete (PC) and Coarse Aggregate Polymer Concrete (CPC). Besides, the characteristics of the interface behavior was also analyzed from the aspect of the interface slip and the shear stress. In the end, the calculation method for the interface stiffness was proposed. The procedure can be used in design. The slip range of these three sorts of repair materials is indicated by the test results of this study as follows, 900–1500 μm for SBR, 3000–9000 μm for PC and 6000–15,000 μm for CPC, and the interface stiffness of each material is 110.44 N/mm 3 , 45.65 N/mm 3 and 10.58 N/mm 3 respectively. [ABSTRACT FROM AUTHOR]

Few studies have been conducted on horizontal shifting prediction models that consider block shapes and laying patterns for block pavements. To develop a prediction model, a combination of different block shapes and laying patterns was evaluated by computer modeling and laboratory tests. The relationship between the force and displacement was recorded via a photogrammetric method using a friction tester. In order to quantify the recorded video results, rigid body analysis was performed. The results of laboratory experiments and the rigid body analysis offered a good match. A displacement vector was used to express the movement of the block with time, according to the start and end position information of each block. Also, a concept of Specific D-Moment (SDM) was proposed to describe the relationship between the movement of the individual blocks and the entire movement. A horizontal shifting mechanistic-empirical prediction model of concrete block pavement is proposed based on regression analysis of the existing performance data. According to the prediction model, higher SDM values give lower cumulative amounts of horizontal shifting due to traffic. [ABSTRACT FROM AUTHOR]

Pervious pavement has been used widely due to efficient hydrological characteristics such as reduction of runoff during floods, providing delay of rainwater into sewer systems and ground water quality improvement. However, clogging prevents it from functioning properly due to sedimentation after a short period of service, which results to poor permeability and performance of pervious pavement. In this study, the causes of clogging were investigated and a clogging simulator was developed in order to evaluate the sustainable permeability of porous concrete block pavement in advance. Furthermore, a test method for verifying the sustainability of infiltration which can predict and assess the permeability performance by years of service was proposed. In addition, the penetration of contaminants also varies depending on vehicle vibration and the rainwater that permeates together with it. It was found that the pores were easily clogged with the vibration frequency increased, but with the amount of contaminants increased to a degree clogging had less influence on vibration. When various types of porous concrete block pavers were evaluated with the proposed sustainable permeability test method, the coefficient of permeability before and after the test have shown very high correlation. [ABSTRACT FROM AUTHOR]

A new type of compliant polymer concrete for runway repair is introduced in this paper. To enhance the compliance of epoxy-based polymer concrete, some epoxy resin was replaced with liquid-type silicone rubber or tire waste powder. To estimate the temperature dependency of the mechanical behavior of the compliant polymer concretes, mechanical tests were also carried out. It was found that tire waste powder was more efficient than the silicone rubber in terms of mechanical performance. The experimental work revealed the 72:20:08(T) specimen provided the highest ductility factor while keeping the compressive strength above the minimum required value (30 MPa). [ABSTRACT FROM AUTHOR]

Highlights: [•] We proposed a joint spalling mechanism under traffic and thermal loadings in JPCP. [•] Finite element method was applied to evaluate the principal shear stresses at joints. [•] Field spalling exponentially grows with the accumulated principal shear stress. [•] A mechanistic-empirical spalling prediction model was developed based on LTPP data. [Copyright &y& Elsevier]

Abstract: Various preformed joint sealants (PJS) can be used for joint concrete pavement (JCP) to prevent the JCP from distresses such as pumping and faulting. Even though PJS have an important role in concrete pavement structures, most of the test methods that assess PJS focus on evaluating their basic mechanical and chemical properties rather than performance-related properties. In this study, a tester for PJS is developed and utilized to determine the resistant stiffness, which is considered to be a performance-related parameter, of PJS in transverse joints. The resistant stiffness is determined by dividing the peak force by the displacement; and the normalized value, which is used to simplify the relationship between the joint width and the sealant width, is determined by dividing the joint width by the sealant width. From laboratory tests performed on the developed tester, it is found that the resistant stiffness and normalized value are representative parameters that can be used to recommend the proper width of the joint, regardless of the joint width and joint type. Also, the relationship between the slip-down distress and the joint width, which is obtained from field survey results, can be utilized to recommend a minimum width for PJS. [ABSTRACT FROM AUTHOR]