This research is aimed at investigating the mechanical behavior of the bitumen by the addition of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) obtained from waste plastic bottles and bags. Polymers (HDPE and LDPE) with percentages of 0%, 2%, 4%, and 6% in shredded form by weight of bitumen were used to evaluate the spectroscopic, structural, morphological, and rheological properties of polymer-modified binders. The rheological properties for different factors; viscosity (ἠ) from Rotational Viscometer (RV), rutting factor G*/Sin (δ), fatigue characteristics G*. Sin (δ), for the modified binder from dynamic shear rheometer (DSR), Short and long-term aging from rolling thin film oven (RTFO), and pressure aging vessel (PAV) was determined. The thermal characteristics, grain size, and texture of polymers for both LDPE and HDPE were found using bending beam rheometer (BBR) and X-ray diffraction (XRD), respectively. Fourier transform infrared (FTIR) analysis revealed the presence of polymer contents in the modified binder. Scanning electron microscopy (SEM) images revealed the presence of HDPE and LDPE particles on the surface of the binder. Creep Rate (m) and Stiffness (S) analysis in relationship with temperature showed a deduction in stress rate relaxation. Results have revealed the best rutting resistance for 6% HDPE. It also showed an improvement of 95.27% in G*/Sin (δ) which increased the performance of the bituminous mix. Similarly, the addition of 4% LDPE resulted in maximum dynamic viscosity irrespective of the temperatures. Moreover, fatigue resistance has shown a significant change with the HDPE and LDPE. The festinating features of waste plastic modified binder make it important to be used in the new construction of roads to address the high viscosity and mixing problems produced by plastic waste and to improve the performance of flexible pavements all over the world.

Road safety is the main problem in developing countries. Every year, millions of people die in road traffic accidents, resulting in huge losses of humankind and the economy. This study focuses on the road traffic accident analysis and identification of black spots on the Lahore-Islamabad Highway M-2. Official data of road traffic accidents were collected from National Highway and Highway Police (NH & MP) Pakistan. The data was digitized on MS Excel and Origin Pro. The accident Point weightage (APW) method was employed to identify the black spots and rank of the top ten black spots. The analysis shows that the trend of road traffic accidents on M-2 was characterized by a high rate of fatal accidents of 35.3%. Human errors account for 66.8% as the major contributing factors in road traffic accidents, while vehicle errors (25.6%) and environmental factors (7.6%) were secondary and tertiary contributing factors. The main causes of road traffic accidents were the dozing on the wheel (27.9%), the careless driving (24.6%), tyre burst (11.7%), and the brakes failure (7.4%). Kallar Kahar (Salt Range) was identified as a black spot (223 km, 224 km, 225 km, 229 km, and 234 km) due to vehicle brake failure. The human error was a major contributory factor in road traffic accidents, therefore public awareness campaign on road safety is inevitable and use of the dozen alarm to overcome dozing on the wheel. Doi: 10.28991/cej-2020-03091629 Full Text: PDF

Increasing the cost of electricity and the global obligations for efficient use of energy have added additional pressure to industrial companies in an already challenging market. Manufacturing companies are adopting methods to have a greater agility to respond quicker to the market dynamics and varying demands by changing production configurations. In recent years, deploying virtual engineering design approaches and extensive simulation methods have facilitated an early insight into how a system may perform, in advance of the physical build. However, the impact of system reconfiguration on the cost of energy consumption is typically unknown. Much research has been carried out on the development of new energy-efficient drives (e.g. motors and actuators) and also the possibility of turning off the drives when idle to save energy. However, in this article, the authors propose a new method of energy saving for engineering production lines by fine tuning the low level device motions to optimise energy consumption. An integration method between virtual engineering design and simulation modelling is proposed, and as a result a simulation method for energy optimisation is developed. In this article the method of interpreting virtual design data for use in simulation modelling of a production assembly line in an automotive industry is discussed. Furthermore, a developed algorithm for optimising energy usage based on adjusting dynamic properties of the system components (e.g. accelerations, torque and mass) is discussed and the result of implementing the concept in an experimental application in the powertrain industry is reported.

Virtual engineering (VE) environment helps to verify process and resource design through visualisation. By using VE, the impacts of re-configurability and new-process additions in the machine stops can be viewed down to the component level. On the other hand, discrete event simulation (DES) typically forecasts the system behaviour over a period of time to predict future performance. During pre-build stages of machines, DES analysis comes with uncertainties, as most of the parameters in the model are based on the assumptions. Therefore, it was aimed to use the validated and verified data, for example ‘process time’ of a machine component available from the VE-emulated systems, in the DES model. Thus, a systematic algorithm was proposed to integrate the VE tool data, with the DES. This article presents the development of a package known as ‘virtual-driven discrete event simulation’ (VDSim), used to establish an integration between the VE and DES domains. The success of this integration depends upon the quality of information and the compatibility of data flow between these independent domains. VDSim integration will help productivity planners and schedulers to get the best possible options for resource selection at stages even when the resource is not physically present.

Despite its worldwide adoption in many countries, rubberized asphalt mixtures are not fully incorporated as an alternative paving material in current Italian road specifications. This reluctance stems from a lack of experience, resistance to change in established work practices, and, sometimes, insufficient evidence demonstrating tangible benefits with local specifications. Furthermore, conventional characterization methods such as void checks and indirect tensile strength testing by means of IDT may not accurately capture the true benefits of using alternative paving materials. This study introduces performance-driven characterization approaches with the final aim of evaluating whether more advanced procedures may provide additional information compared to current practices and, in turn, promote the use of alternative paving materials. Hence, an investigation has been conducted to compare the rutting behavior of conventional asphalt mixtures with those modified with engineered crumb rubber (ECR). This comparison utilized performance-driven characterization approaches, including a basic IDT-based methodology at higher temperatures (HT-IDT), as well as two more sophisticated approaches, the Stress Sweep Rutting (SSR) and Flow Number (FN) tests, using the asphalt mixture performance tester (AMPT). Finally, the results were compared with those obtained using the IDT, a conventional method as specified by the major Italian road authority. As a result, the addition of ECR proves beneficial in enhancing the qualities of dense mixtures tailored for use on urban and secondary roads; however, only performance-driven characterization, with both basic and advanced methodologies, can clearly describe the pivotal role of ECR in achieving discernible enhancements in the rutting behavior of asphalt mixtures.

Even though alternative paving materials, like rubberized asphalt, are sometimes present in specifications, these are still not widely adopted from road agencies mainly due to a lack of experience, reticence in changing work habits and, often, a lack of evidence of real gains in the change. Authors believe that performance-based laboratory characterization is a solution to highlight differences with conventional asphalt mixtures. Hence, this research wants to highlight the differences between designing asphalt mixtures modified with engineered crumb rubber (ECR) on the basis of conventional indirect tensile testing (ITS), as prescribed by Italian specifications, and by means of performance-related characterization. ECR allows to asphalt mixtures to be modified through a dry process without inconveniences such as uncontrolled swelling and the generation of fumes; on the other hand, performance-related characterization focuses on highlighting rutting behavior by using a basic approach, still based on ITS, and a more advanced viscoplastic methodology using the asphalt mixture performance tester (AMPT). As a result, performance-related characterization is necessary to highlight clear gains in the rutting behavior of the asphalt mixtures modified with ECR. Advanced methodology by means of AMPT provides a fine-tuned characterization; however, the basic approach by means of ITS already highlights the differences in performance. ECR could be widely used to improve the properties of dense mixtures for roads with low traffic; in fact, it solves many of the practical issues of adding crumb rubber through a dry process and greatly improves paving material properties compared to conventional asphalt mixtures, with an increase in cost of only 10%.