Crack detection has recently gained credence in the field of engineering automation. Engineered cementitious composites (ECC) are a durable, and environmentally friendly construction material and a suitable replacement for conventional concrete. As such, there is a need to automate the process of detecting the unique ductile crack formation and growth in ECC. This research focuses on detecting ECC cracks, accurately mapping the crack morphology, and predicting the crack growth patterns of this advanced material. We design and present a novel generative adversarial algorithm named Residual Pyramidal Generative Adversarial Network (RP-GAN), capable of ECC crack detection. RP-GAN is an enhanced and improved version of the typical Pix2Pix GAN for paired image-to-image translation. It is an extensive network that could be used for macro and micro-segmentation purposes in addition to domain translation tasks. In this research, we first investigate the ability of RP-GAN to detect ECC micro-cracks… Details

Leak proof tube-to-tube sheet joints are mandatory for the optimal operation and longevity of the shell and tube heat exchanger. Tube-to-tube sheet joints play a crucial role as fluid barriers, ensuring effective separation between the tube and shell side fluids within shell and tube heat exchangers. Non-conventional friction stir welding, known for imparting less residual stresses, is not commercially used for the fabrication of tube-to-tube sheet joints due to complex joint configuration and geometrical limitations. An extensive study on friction stir welding considering the geometrical parameters of tube-to-tube sheet arrangement is highly demanded. This research examined the mutual influence of radial clearance ranging from 0 mm to 0.5 mm and tube projection lying from 1 mm to 2 mm in friction stir welding of tube to tube sheet configuration on the pull-out strength, extension and, hardness at the stirring and fusion zones. Optimum radial clearance and tube projection for achieving… Details

This paper aims to comparatively evaluate the compressive and flexural response of high strength and ultra-high-performance polyvinyl Alcohol (PVA)- and polyethylene (PE)-reinforced ECCs at fiber contents of 1.75 vol% and 2.25 vol%, utilizing the same base mixture design. The base mixture was formulated with the objective of reducing the reliance on Portland cement by replacing 55% of it with supplementary cementitious materials (fly ash and silica fume). The flexural loading protocol consisted of monotonic loading with a displacement rate of 0.3 mm/min and 2.0 mm/min, and a repeated/cyclic loading with a displacement rate of 2.0 mm/min. The developed PVA- and PE-reinforced ECCs exhibited significant enhancements in average compressive strength, with PVA-reinforced ECC showing a 19% improvement and PE-reinforced ECC demonstrating a 39% improvement compared to the control specimen. In terms of flexural strength, PVA-reinforced ECC exhibited a 51% enhancement, while PE-reinforced ECC achieved… Details

The primary challenge encountered by polymers and their composites when exposed to saline water is their inadequate ability to withstand wear and tear over time. With a potential to replace conventional materials the long-term performance of FRP composites is still a novice area. This manuscript thus, reports an experimental investigation and prediction of the durability of fiber-reinforced polymer composites exposed to seawater at different temperatures. E-glass/epoxy and E-glass/polyurethane samples were exposed to 23 °C, 45 °C and 65 °C seawater for up to 2700 days (90 months). Tensile tests evaluated the mechanical performance of the composite as a function of exposure time, and strength-based technique was used to assess the durability. The experimental results revealed that the tensile strength of E-glass/epoxy composite decreased by 6.3% and 48.9% after 90 months in seawater at 23 and 65 °C, respectively, whereas it declined by 37.6% and 63.6% respectively for E-glass/Polyurethane… Details

This project addresses the contemporary challenges faced by the transportation workforce, influenced by demographic shifts, labor market fluctuations, and the growing demand for interdisciplinary skills. Using a case study of the southeastern United States, five main objectives guided the project: a) synthesizing the current state of workforce development practices, b) identifying key challenges in the transportation workforce, c) defining the term “workforce development” within this context, d) exploring potential roles of University Transportation Centers (UTCs) in tackling these challenges, and e) offering actionable recommendations for enhancing transportation workforce development. The research used findings from a literature review, stakeholder meetings, a survey of transportation professionals, and personal interviews with selected experts. The findings were integrated to derive conclusive results instead of independently interpreting each dataset. The study revealed that workforce… Details

Recent revisions to federal guidelines require state departments of transportation (DOTs) to rate bridges in their inventory with special hauling vehicles (SHVs) and emergency vehicles (EVs). In this research, refined analysis method was used to compute live load distribution factors of steel girder bridges considering the impacts of SHVs and EVs on the live load distribution behavior. To determine the live load distribution factors for interior and exterior girders under different lane loading conditions, finite element models of twenty-one steel girder bridges from the state of Virginia were developed and then analyzed. The effects of vehicle type and transverse position on the results of the refined analysis were evaluated. The results were comparatively evaluated with those obtained using AASHTO LRFD equations. The live load distribution factor of steel girder bridges with various geometrical parameters were predicted using a series of linear regression models that were built using… Details

Crack morphology is a major indicator of pavement distress and can indicate the extent of pavement rehabilitation required. Researchers have investigated the detection of cracks using images captured at close proximity. This is often time-consuming, labor-intensive, and inefficient. This research implemented the weighted ensemble technique for detecting pavement cracks on a pixel level using UAV images obtained at high elevations. The images were trained using five deep convolutional neural network architectures: UNet, Vgg-UNet, Resnet-UNet, Inception-UNet, and PaveNet. The pixel-level crack detection results are combined using the ensemble technique to maximize performance. The performance of the ensemble methodology was evaluated and compared with some of the state-of-the-art networks. The predictions obtained were used to estimate the area, length, and mean width of the cracks in the pavement images. It is worth noting that the proposed system can be applied to a specific road segment.… Details

Concrete is the most utilized material (i.e., average production of 2 billion tons per year) for the construction of buildings, bridges, roads, dams, and several other important infrastructures. The strength and durability of these structures largely depend on the compressive strength of the concrete. The compressive strength of concrete depends on the proportionality of the key constituents (i.e., fine aggregate, coarse aggregate, cement, and water). However, the optimization of the constituent proportions (i.e., matrix design) to achieve high-strength concrete is a challenging task. Furthermore, it is essential to reduce the carbon footprint of the cementitious composites through the optimization of the matrix. In this research, machine learning algorithms including regression models, tree regression models, support vector regression (SVR), ensemble regression (ER), and gaussian process regression (GPR) were utilized to predict the compressive and tensile concrete strength. Also, the… Details

Tube-to-tubesheet joints play a crucial role in providing structural integrity to the shell and tube heat exchangers. This research investigated the combined effect of roller expansion percentages and grooves on the performance of expanded and welded-expanded tube-to-tubesheet joints. The results indicated that the joint strength of welded-expanded (except for 6% tube expansion and 2 grooves) and welded joints exceeded the nominal axial strength of the tube, 404.90 MPa. The highest tube pull-out strength of 290.77 MPa in the expanded only joint (10% tube expansion and 2 grooves), lesser than the axial strength of the tube by 28.25%, suggested avoiding the expansion process alone for 23 mm thick tubesheets. High dilution and inadequate minimum leak path (<1.78 mm) result in the failure of the welded-expanded joint. The highest hardness of 216 HV is formed at the weld zone comprising of a ferrite and widmanstatten ferrite. From 4% to 10% tube expansion percentages, the grains at the inner… Details

Precast concrete sandwich panels (PCSPs) are utilized for the external cladding of structures (i.e., residential, and commercial) due to their high thermal efficiency and adequate composite action that resist applied loads. PCSPs are composed of an insulating layer with high thermal resistance that is mechanically connected to the concrete. In the recent decades, PCSPs have been a viable alternative for the fast deployment of structures due to the low fabrication and maintenance cost. Furthermore, the construction of light and thin concrete wythes that can transfer and resist shear loads has been achieved with the utilization of high-performance cementitious composites. As a result, engineers prefer PCSPs for building construction. PCSP design and use have been examined to guarantee that a building is energy efficient, has structural integrity, is sustainable, is comfortable, and is safe. Hence, this paper reviews the expanding knowledge regarding the current development of the mechanical… Details