Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 6 Articles
This paper presents a practical approach for prioritization of bridge maintenance within a given bridge network. The maintenance\nprioritization is formulated as a multiobjective optimization problem where the simultaneous satisfaction of several conflicting\nobjectives includes minimization of maintenance costs, maximization of bridge deck condition, and minimization of traffic\ndisruption and associated user costs. The prevalence of user cost during maintenance period is twofold; the first case refers to the\nperiod of dry season where normally the traffic flow is diverted to alternative routes usually resurfaced to regain traffic access. The\nsecond prevalence refers to the absence of alternative routes which is often the case in the least developed countries; in this case the\nuser cost referred to results fromthe waiting time while the traffic flow is put on hold awaiting accomplishment of the maintenance\nactivity. This paper deals with the second scenario of traffic closure in the absence of alternative diversion routes which in essence\nresults in extreme user cost. The paper shows that themultiobjective optimization approach remains valid for extreme cases of user\ncosts in the absence of detour roads as often is the scenario in countries with extreme poor road infrastructure...
Reinforced concrete structures, especially those in marine environments, are commonly subjected to high concentrations of\nchlorides, which eventually leads to corrosion of the embedded reinforcing steel. The total time to corrosion of such structures\nmay be divided into three stages: corrosion initiation, cracking, and damage periods. This paper evaluates, both empirically and\nexperimentally, the expected time to corrosion of reinforced concrete structures. The tested reinforced concrete samples were\nsubjected to ten alternative curing techniques, including hot, cold, and normal temperatures, prior to testing. The corrosion\ninitiation, cracking, and damage periods in this investigation were experimentally monitored by an accelerated corrosion test\nperformed on reinforced concrete samples. Alternatively, the corrosion initiation time for counterpart samples was empirically\npredicted using Fick�s second law of diffusion for comparison. The results showed that the corrosion initiation periods obtained\nexperimentally were comparable to those obtained empirically. The corrosion initiation was found to occur at the first jump of the\ncurrent measurement in the accelerated corrosion test which matched the half-cell potential reading of around ?350mV....
Watershed has been adopted as an approach for the implementation of area development programs namely DPAP, DDP, IWDP and HARIYALI. A watershed is a natural geo-hydrological area that drains out rain water to a common point. Based on available budget, local people support and intervention with technologies, the watershed area is developed. Such viable watershed unit aims at conservation, development and optimum use of natural resources for increasing productivity and upliftment of socio-economic status of rural community on sustained basis.Jharkhand is endowed with natural resources such as surface water and ground water, land with immense bio-diversity, moderate climate, manpower, adequate availability of power, which are the basic essentials for the growth and development of agriculture based industries. Modalities of watershed development program are community organization, capacity building and conservation of natural resources i.e. land, water, vegetation, livestock and human.The paper is based on a review of watershed development program operational in villages of Jharkhand. This paper has identified lots of specific technical (water and soil) and behavioral issues for proper planning and implementation of watershed development program in Jharkhand....
Optical imaging is a commonly used technique in civil engineering for aiding the archival of damage scenes and more recently for\nimage analysis-based damage quantification. However, the limitations are evident when applying optical imaging in the field.The\nmost significant one is the lacking of computing and processing capability in the real time.The advancement ofmobile imaging and\ncomputing technologies provides a promising opportunity to change this norm. This paper first provides a timely introduction of\nthe state-of-the-art mobile imaging and computing technologies for the purpose of engineering application development. Further\nwe propose a mobile imaging and computing (MIC) framework for conducting intelligent condition assessment for constructed\nobjects, which features in situ imaging and real-time damage analysis. This framework synthesizes advanced mobile technologies\nwith three innovative features: (i) context-enabled image collection, (ii) interactive image preprocessing, and (iii) real-time image\nanalysis and analytics.Through performance evaluation and field experiments, this paper demonstrates the feasibility and efficiency\nof the proposed framework...
In this paper a general solution to the geometrically nonlinear dynamic analysis of plates stiffened by arbitrarily placed parallel\nbeams of arbitrary doubly symmetric cross-section, subjected to dynamic loading, is presented.Theplate-beamstructure is assumed\nto undergo moderate large deflections and the nonlinear analysis is carried out by retaining nonlinear terms in the kinematical\nrelations. According to the proposed model, the arbitrarily placed parallel stiffening beams are isolated fromthe plate by sections in\nthe lower outer surface of the plate, making the hypothesis that the plate and the beams can slip in all directions of the connection\nwithout separation and taking into account the arising tractions in all directions at the fictitious interfaces. These tractions are\nintegrated with respect to each half of the interface width resulting in two interface lines, along which the loading of the beams and\nthe additional loading of the plate are defined. Six boundary value problems are formulated and solved using the analog equation\nmethod (AEM), a BEM-based method. Both free and forced transverse vibrations are considered and numerical examples with\ngreat practical interest are presented demonstrating the effectiveness, wherever possible, the accuracy, and the range of applications\nof the proposed method....
This study investigates the ameliorative effects on some properties of cement-based materials which can be obtained by\nincorporating rubber particles as part of the fine aggregates. The aim is to find out optimal cement composite/mortar mixtures,\ncontaining recycled-tyre rubber particles, suitable for specific engineering applications. Different percentages of rubber particles,\nfrom 0% to 75%, were used and, for each percentage, the suitable amount of sand was investigated in order to achieve the best\nfresh/hardened performances. In particular the following characteristics were examined: density, compressive strength, modulus\nof elasticity, shrinkage, weight loss, flexural behaviour, thermal conductivity, rapid freezing and thawing durability, and chloride\npermeability. The experimental results were compared with the ones of cement composite specimens without rubber aggregates.\nTest results show that the proposed rubberized mortar mixes are particularly suitable for some industrial and architectural\napplications, such as under-rail bearings, road constructions, paving slabs, false facades, and stone backing....
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