Search results for "Civil Engineering"
showing 10 items of 1216 documents
Simplified analytical models for compressed concrete columns confined by FRP and FRCM system
2017
In order to consider the response of concrete columns confined by FRP and FRCM system, proper models have to be formulated. In this context the present paper shows a generalized criterion for the determination of the increase in strength, in ductility and in dissipated energy for varying corner radius ratio of the cross section and fiber volumetric ratio. The procedure is based on the best fitting of several experimental data and unlike the usual empirical approaches available in the literature, the proposed technique relates the confinement effectiveness to a single parameter representative of the relative stiffness between the original concrete core and the reinforcement system. Furthermo…
Selecting a small run-of-river hydropower plan by the analytic hierarchy process (AHP): A case study of Miño-Sil river basin, Spain
2015
Hydroelectric power is obtained by harnessing the potential energy of a mass of water flowing along a river bed to convert it first into mechanical and then into electrical energy. The system is therefore both clean and autonomous and has a high potential for development. A small hydropower plant has an installed power capacity of below 10 MW and is considered run-of-river when it diverts part of a river flow to generate its electricity. The use of multicriteria techniques in environmental decision making, including selecting between various alternatives, is important when it involves complex decisions in a number of disciplinary fields. The most widely used of these techniques is the analy…
Contributions to risk assessment in the departments of welding mechanical engineering companies
2017
The risk assessment professional should cover every activity and every workstation in an enterprise engineering, considering each component of the production system (the system working), each duty, work equipment and working environment. This represents an extremely complicated and complex problem because of production system that is a powerful polluting technology, especially of the atmosphere and soil. The formation of gas welding process is the result of electrodes burning, fluxes, and development of bath fused metal the welded seam. In welding processes, human operators are exposed to smoke and toxic gases, arising from the welding process, which can be dangerous to health. Many acute i…
Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 1-Review of Design Methods
2012
AbstractWhen selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating soils that are not suitable for road or railways construction.Advances in lime stabilization technique allowed the successful use of this technique also for improving the bearing capacity of the subgrade, with noticeable savings on both aggregate and disposal charges.In this paper a review of internationally adopted design methods for soil-lime mixture is presented, in order to compare testing methods and requirements of the adopted criteria, as discussed in Part 2.
Environmental analysis of different construction techniques and maintenance activities for a typical local road
2017
Abstract In this paper, considering the sever impact of road infrastructures on both the surrounding environment as well as on the consumption of locally available natural resources, different road construction techniques have been studied and compared, in order to be able to rank the best solution in terms of environmental sustainability. For the aims of this study, a Life Cycle Analysis has been carried out on a road infrastructure with the most representative geometrical characteristics among those widely used in Italy, in suburban areas, with the help of an appropriate software, the PaLATE. The environmental effects due to both the use of recycled materials, such as the Reclaimed Asphal…
Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 2-Experimental Validation
2012
AbstractAs detailed in Part 1, the most common Italian Technical Specifications refer to different design methodologies for design of lime-soil mixtures, some being quite different from those internationally adopted. Therefore, it seemed appropriate to the Authors to compare these methodologies, via a wide experimental program.It is shown that the Italian methodology of the National Road Agency is different not only from those used in Italy, but also from the main international standards. The experimental results highlight that a revision of that methodology is needed in order to bring it into line with what is prescribed by the European standard.
Polymer-Functionalised Nanograins of Mg-Doped Amorphous Calcium Carbonate via a Flow-Chemistry Approach
2019
Calcareous biominerals typically feature a hybrid nanogranular structure consisting of calcium carbonate nanograins coated with organic matrices. This nanogranular organisation has a beneficial effect on the functionality of these bioceramics. In this feasibility study, we successfully employed a flow-chemistry approach to precipitate Mg-doped amorphous calcium carbonate particles functionalized by negatively charged polyelectrolytes&mdash
Immobilised Humic Substances as Low-Cost Sorbents for Emerging Contaminants
2021
Environmental pollution with contaminants of emerging concern (CECs) is a worldwide problem that is receiving increasing attention. Although these substances have been released in the aquatic environment for a long time, wastewater treatment plants are still incapable of removing emerging contaminants completely. Consequently, trace metals, metalloids and pharmaceuticals, as well as surfactant leftovers, are often found in environmental samples. Environmentally friendly and cost-effective sorbents such as humic substances can be used for purification if their sorption properties are increased by immobilization. To our knowledge, immobilized humic substances have not been widely studied as s…
Novel biomass fly ash-based geopolymeric mortars using lime slaker grits as aggregate for applications in construction: Influence of granulometry and…
2019
Abstract This work discusses the influence of the aggregate granulometry and the binder/aggregate ratio on the engineering properties of novel green geopolymeric mortars. Two wastes generated by a Portuguese Kraft pulp industry are employed to manufacture the material: lime slaker grits (used as aggregate) and biomass fly ash (to partially replace the metakaolin − 70 wt% substitution). The novel geopolymeric mortars could find innovative applications as sustainable construction materials. The studied mix design foresees the use of several grits granulometric ranges and ratios binder/aggregate to discuss workability, water sorptivity, and mechanical performance of the novel mortars. To date,…
Mathematical Modeling and Parameters Estimation of Car Crash Using Eigensystem Realization Algorithm and Curve-Fitting Approaches
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/262196 Open Access An eigensystem realization algorithm (ERA) approach for estimating the structural system matrices is proposed in this paper using the measurements of acceleration data available from the real crash test. A mathematical model that represents the real vehicle frontal crash scenario is presented. The model's structure is a double-spring-mass-damper system, whereby the front mass represents the vehicle-chassis and the rear mass represents the passenger compartment. The physical parameters of the model are estimated using cu…