Civil Engineering

The 3R program is a waste management program that starts from upstream to downstream through reducing, reusing and recycling waste. This study aims to evaluate the success level of 3R based waste management and to identify the level of importance and satisfaction of the community towards the construction of 3R waste treatment facility in Aceh Province. This research uses qualitative method through observation and interview and quantitative method through questionnaire. Evaluation of 3R TPS management activities was conducted through observation and interviews with KSM chairmen based on technical guidance from the Ministry of Public Works and People's Housing (2016). The identification of the level of importance and satisfaction of the community towards the development of 3R TPS facilities is done through the distribution of questionnaires to the local community. Data processing used validity and reliability test, while data analysis used descriptive analysis through Statistical ...

A new simple “four-variable shear deformation” plate model is proposed in this work to demonstrate the hygro-thermal environment effects on dynamic and buckling of functionally graded material “sandwich plates” supported by “Winkler–Pasternak” elastic foundations. Equations of motion are obtained from Hamilton’s principle containing the hygro-thermal influences. This model uses only “four variables” and considers trigonometric variation of “transverse shear stress.” In addition, these stresses become zero at the upper and lower surfaces of the “sandwich plate.” The novelty of this formulation is the addition of the integral term in the field of displacement, which leads to a reduction of the number of unknowns and basic equations. Various kinds of functionally graded material “sandwich plates” are examined in this study. To verify the validity of the model, the calculated results are compared with the existing results. Comparison investigations reveal that the computed results of th...

Purpose This paper aims to investigate the role of shapes of containers (nine different containers) on entropy generation minimization involving identical cross-sectional area (1 sq. unit) in the presence of identical heating (isothermal). The nine containers are categorized into three classes based on their geometric similarities (Class 1: square, tilted square and parallelogram; Class 2: trapezoidal type 1, trapezoidal type 2 and triangular; Class 3: convex, concave and curved triangular). Design/methodology/approach Galerkin finite element method is used to solve the governing equations for a representative fluid (engine oil: Pr = 155) at Ra = 103–105. In addition, finite element method is used to solve the streamfunction equation and evaluate the entropy generation terms (Sψ and Sθ). Average Nusselt number ( Nub¯) and average dimensionless spatial temperature ( θ^) are also evaluated via the finite element basis sets. Findings Based on larger Nub¯, larger θ^ and optimal Stotal v...

The paper considers 4 types of mineral additives for concrete - metakaolin, silica fume, wollastonite and zeolite - and their influence on the rheological properties and strength of fine-grained concrete, in which part of the cement is replaced by a mineral additive. It is shown that the replacement of 5-10% of cement with active mineral additives with a specific surface area 1.5 times or more greater than the specific surface area of cement (metakaolin, silica fume) leads to a decrease in the flowability of the mixture in proportion to the increase in the amount of additive in the system. When replacing 10% of cement with additives, the specific surface of which relative to cement is in the range of 0.88-1.2 (wollastonite, zeolite), on the contrary, increases the flowability of the mixture. The strength of all samples with mineral additives at 28 days of age was greater than that of the control composition. An increase in strength by 1.7-1.76 times is noted for compositions with th...

Vineyards represent complex Mediterranean agrosystems that deliver significant ecosystem services to society. Yet, many vine-growers still need to assimilate the importance of crop and soil management to the conservation of soil and water resources. The main objective of this study was to evaluate water use and the water balance terms in rainfed and irrigated vineyards in Italy and Portugal, respectively, in both cases aiming at the sustainability of natural resources use. The SIMDualKc model is used for both sites after calibration and validation by fitting soil water content measurements. The Italian case study focused on the impacts of inter-row conservation management in hillslope vineyards while the Portuguese case study analyzed irrigation water management under scarcity in flat vineyards. For the Italian vineyards, the model results focused on the evapotranspiration fluxes and their partition, control of surface runoff, and soil water recharge provided by the inter-row soil m...

As a non-destructive technique for concrete compressive strength assessment for existing concrete structures, Ultrasonic Pulse Velocity (UPV) test method has been widely used. Since the UPV affected by many factors, it is not easy to accurately assess the concrete compressive strength. Effect of some factors which are coarse aggregate grading type, slump, the water-cement ratio (w/c), sand volume ratio, coarse aggregate volume ratio, testing age, concrete density, and pressure of steam curing, were analyzed on the relationship between ultrasonic pulse velocity and concrete strength. 436 records of data, extracted from published research work, were used to build seven supervised machine learning regression models which are; Artificial Neural Network (ANN), Support Vector Machine (SVM), Chi-squared Automatic Interaction Detector (CHAID) decision tree, Classification and Regression Trees (CART) decision tree, non-linear regression, linear regression, and stepwise linear regression mode...

Highways are of essential importance, since they are the main mode of transportation in the country, with a vast territorial extension of roads. However, many of these highways present some kind of alteration in their initial shape. The concept of paving, pathologies and their causes, as well as their recovery, are thus constituted. These problems were visually evaluated according to the Asphalt Pavement Restoration Manual of the DNIT (National Department of Transportation Infrastructure) in accordance with the TER 005/2003 and PRO 009/2003 standards, in a different area of the city of Manaus, namely the South Zone, consisting of the roads of the Industrial Complex, which allows the transportation of containerized cargo to the ports. The results, based on the visual surveys carried out and the current serviceability values, indicated roads with a concept between bad and regular.

Structures built along near shore tend to disrupts coastal processes at different levels depending on the type and manner of construction. This disruption will result into poor water circulation which may affect biological activities, sediments dynamics and coastal protection from inclement weather. Breakwaters are often constructed to minimize impact of stronger waves. Rock mound oyster bed was proposed to help rock oyster producer improve their production, however some environmental issues were noted such as uneven oyster density distribution and sediments accumulation which are associated to water circulation/movement disruption and more importantly the resilience of the mounds itself from stronger waves. This paper explores proposed strategy how the environmental impact to the rock mounds can be enhanced using a laboratory model of a typical coastal zone where rock oyster mounds can be established.

This paper presents a new strengthening concept proposed for road bridges in the project SUREBridge (Sustainable Refurbishment of Existing Bridges), co-funded by the European Commission through the ERA-NET Plus Infravation 2014 Call. The project proposes an innovative and holistic refurbishment approach by using fiber-reinforced polymer (FRP) materials. The approach is designed for bridge upgrading, including repair and strengthening actions in the most effective and efficient way in terms of reducing construction time, resource consumption, and traffic disruption. SUREBridge concept consists of bonding prestressed carbon fiber reinforced polymer (CFRP) laminates to the tensile parts of flexural members (such as bottom flange of girders), and installing glass fiber reinforced polymer (GFRP) panels to the compressive parts (such as top of the existing concrete deck). A novel prestressing system is used to apply prestressed CFRP laminates eliminating the need for mechanical anchorage ...

This study allows to analyze the influence of the teeth number of the milling cutter during end milling machining on the surface quality, mechanical characteristics, cutting forces, are valuable in terms of providing high precision and efficient machining in order to give a new approach to improve the surface quality of a mechanical part, reducing residual stresses, cutting forces by the material removal process. The Surface roughness is particularly sensitive to the runout errors of the insert, number of cutter teeth and the nose radius during this type of machining. This paper is a comparative study of the surface finish, stresses, and cutting forces when machining with a 2, 6 and 8 tooth cutter under the same cutting conditions. In addition to the investigations on the surface integrity and the comparative geometrical study, we have provided a calculation tool to simulate the influence of the residual stresses and the loads applied on the mechanical part. This approach examines t...