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This study was conducted to evaluate the strength and volume change characteristics of a sedimentary residual soil mixed with bentonite (S1) when treated with three different enzymes. In addition, three reference clays including bentonite, illite, and kaolinite were also treated with enzymes to study the effect on their strength characteristics. Soil samples prepared at the optimum moisture content (OMC) were sealed and cured for four months. After curing, reference clays were tested for unconfined compressive strength (UCS). For swell tests, the S1 soil samples were placed on porous stones, which were immersed in water to allow capillary soaking of the samples. S1 samples were allowed to dry at ambient temperature for shrinkage test until the rate of reduction in volume became negligible. On completion of swell tests, the samples were tested for UCS to determine the decrease in strength due to saturation. No increase in strength and decrease in volume change were observed for any of the enzymes and dosages. Field Emission Scanning Electron Microscope (FESEM) showed some dense packing of particles for treated samples, whereas X-ray diffraction (XRD) did not reveal any change; in fact, the pattern for untreated and treated soil samples were indistinguishable. [ABSTRACT FROM AUTHOR]

The use of fiber-reinforced polymer (FRP) jackets as external confinement is becoming popular, especially in seismic areas, because of its ability to enhance the strength and ductility of reinforced concrete to perform as a sustainable symmetric structural member. Therefore, various researchers have worked out for the prediction of strength and strain models of FRP-confined concrete. This study presents the improved strain models for the FRP confined cylindrical concrete members. Different previously proposed models of axial strain of FRP-confined concrete were evaluated based on a large database of 678 specimens from previous experiments and an improved model was proposed using the general regression analysis technique. Furthermore, the proposed model was validated using the previous experimental work of FRP-wrapped concrete cylinders and their finite elements analysis (FEA) using the ABAQUS software. The accuracy of the proposed strain model was quite satisfactory in comparison with the previous experimental and FEA results of the present study. Moreover, the proposed empirical strain model was used for the parametric study to investigate the effect of different geometric and material parameters such as the compressive strength of unconfined concrete, diameter of the cylinder, elastic modulus and thickness of the FRP layers, on the axial strain of FRP-wrapped cylinders. A close agreement among the proposed strain models and experimental outputs was observed. This study will help in understanding the behavior of sustainable FRP-confined symmetric concrete members. [ABSTRACT FROM AUTHOR]

The development of the bus rapid transit system (BRTS) is tremendously growing in developing countries of the world. In large cities, the projection of transportation intends to enhance economic growth and changes the image of the city for both residents and outsiders. The purpose of this research was to study the application of alternative options for energy efficient BRTS in developing countries. The BRTS has some of its accessibility patterns that relate to the socio-economic strata. A decision-making efficiency analysis methodology has been applied to analyze the comparative analysis of both conventional fuel and hybrid bus systems for the Multan city of Pakistan. The section-wise application of a hybrid energy-based bus system has been analyzed in comparison to the conventional bus system. Out of 21 stations, the efficiency-wise hybrid bus system remained superior or equivalent to the standard value of 1 except one midpoint section. The finding of the analysis indicates that the hybrid mechanism of buses can not only replace a conventional fuel-based system, but will also help as an energy-efficient and eco-friendly economical solution. This study will help to revolutionize the bus rapid transit system in developing countries. [ABSTRACT FROM AUTHOR]

During the development of symmetric asphalt concrete material samples, aggregates play a vital role in the performance of its production. Shape characteristics and aggregates geology are two major factors influencing strength parameters of the asphalt concrete mix. In this study, two different geological sources of aggregates with different shape characterizations have been utilized for the development of the asphalt concrete mix. In addition to that, the stability analysis has been performed under different temperature conditions ranging between 25 and 60 °C. By the application of the destructive technique (DT) and non-destructive technique (NDT), the performance of the asphalt concrete mix has been analyzed and compared based on the geology of aggregates under various temperatures. Furthermore, a statistical model has been developed to analyze the stability and performance of the developed asphalt concrete mix with reference to regional climatic conditions. This study will help in the development of symmetric formation of sustainable asphalt materials. [ABSTRACT FROM AUTHOR]