Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Construction industry comprises a high degree of competition; the performance of construction projects is highly affected by the performance of civil engineers who are the core of construction productivity. Professional development is one of the essential milestones toward improving the performance of civil engineers. This paper, critically, evaluates the professional development and training of civil engineers in Baghdad. This encompassed the study of the existing programs offered for the professional development, the expected impact, and suggestions. Data were collected from 113 professional civil engineers about the existing professional development programs and training courses and analyzed. Large variations were found in terms of the time spent for professional development, despite the fact that they are comparable to some developed countries. Pitfalls in the field of professional training and development were clear. Remedial suggestions including professional development program and appraisal system were presented. It was emphasized that collaborative efforts by all stakeholders are required to ensure sustainable professional development.

As a part of an on-going research program on the mechanical instability of granular soils in our laboratory, defined contents of sand and silt in soil mixtures are studied through the triaxial apparatus, full range of initial relative density states (loose, medium and dense) are experimented and analyzed. In this work, the investigated soil is collected from different depths of Kharouba coastal region in the province of Mostaganem (Lat: 35.96° N; Long: 0.1° E). It consists mainly of sand with a low percentage fraction of non-plastic silt, below 30%. The coastal region of Mostaganem (Kharouba) is very close to the harbor and it experiences a significant seismic activity, then it would be very susceptible to the phenomenon of liquefaction under static or dynamic loads, hence the importance and relevance of this study which introduces the identification parameters of this instability due to liquefaction. Undrained triaxial tests under monotonic loading are carried out in the laboratory on saturated reconstituted samples. These results are presented and analyzed. New parameters for assessing the influence of fines content and density state on the behavior of heterogeneous soils (sand-silt) will be introduced to the liquefaction. New correlations expressing the undrained critical shear with these new parameters will be deducted for full range of initial relative density (loose, medium and dense) for design purpose.

A solution for measuring creep compliance of asphalt binders is obtained by testing samples using a spherical indenter at intermediate temperatures. The initial assumptions considered a semi-infinite medium with no friction. Solutions were obtained to correct for the finite height and radius of the samples. Three non-modified asphalt binders were tested at intermediate temperatures (20 – 25 °C) using three load levels (25 – 50 – 75 g). Three sample radius (25 – 35 – 50 mm) and three sample heights (15 – 30 – 50 mm) were considered, thus obtaining a total of nine sample sizes. The binders were also tested in creep using a dynamic shear rheometer and results were compared with indentation. For the three asphalt binders analyzed, creep compliances obtained by indentation turned to be lower than the values measured using dynamic shear rheometers. One probable reason for this difference is the excessive aging that is induced on the surface of samples to be indented during sample preparation, as well as the effects of friction and indentation depth during testing. Future studies should consider the effect of friction in the indentation, which seem not to be totally negligible.

The aim of this research is to compare the uniformity of the color histograms of the RGB color space between the traditional surface treatment with fire against the controlled surface treatment of colorless acids in liquid state on construction timbers, developed by the authors. A “conceptual translation” is proposed as a starting point, from the processes applied on construction timbers with treatments by means of fire (whose aim is not the color) to controlled surface treatment of colorless acids in liquid state on construction timbers. The color histograms of the RGB color space are compared of both treatments and it is concluded that the controlled surface treatment of colorless acids in liquid state on construction timbers obtains a more uniform distribution of color histograms than the traditional surface treatment with fire.

Architecture is totally linked to the knowledge and study of geometry. The re-entrant hexatruss structure is part of the auxetic structures. These structures, characterized by its negative Poisson’s ratio, change their geometric configuration from a line to a surface and from a surface to a volume or spatial framework. This project is based on establishing those re-entrant hexatruss geometries to be able to build new spaces in architecture, studying analytically geometric and structural properties of auxetic materials and structures that can be a part of the architecture construction.

The Balearic Islands’ Housing Institute (Instituto Balear de la Vivienda-IBAVI), in collaboration with the Directorate General of Nature, Environmental Education, and Climate Change of the government of the Balearic Islands, has received a European grant worth €754,012 from the LIFE+2012 program to carry out the building and monitoring of 14 public housing units in Sant Ferran, Formentera. The main objective of the project is to contribute to the development of technologies, methods, and innovative instruments in the field of nature conservation, climate change, environmental policy, the production of information, and communication on environmental issues in all EU member states. This paper, a collaborative effort between the University of the Balearic Islands and the IBAVI, presents the results obtained for the determination of the bulk density of a layer of Posidonia oceanica used as an insulating material, and which complied with the limitations of thermal conductivity for a thermal insulation solution in a flat roof.

The aim of this research is to assess the influence of the effective water-cement ratio on the concrete workability and strength. This study was carried out with a concrete used for the manufacture of concrete caissons for the construction of a harbour in the south of Tenerife. This commercial concrete was elaborated with basaltic aggregates but with a partial replacement of basalt sand by a sand called "African Sand". As a reference, a concrete containing only basaltic aggregates was manufactured. The water absorption of the aggregates influence the amount of water available for the hydration of the cement. The value of water absorption for the basaltic sand is higher than African sand. This presence of aggregates with different water absorption in the concrete allowed the proposal of a methodology for the determination of the effective water-cement ratio in the fresh concrete. This methodology was used for the calculation of water available for the hydration of the cement in the fresh concrete. The results allowed the answer for two questions regarding the behaviour of these concrete mixes. Firstly, how the incorporation of this African sand influences effective water-cement ratio and the concrete workability. Secondly, how this incorporation influences the strength of the concrete.

Considering the loss of lives and economical loss arising out of earthquake motions, it becomes necessary to determine the safety levels and vulnerability of the existing buildings especially in the urbanized areas and to take due precautions. As a matter of fact, it is not convenient to determine the safety levels of a large number of structures by using the common analysis methods with respect to the temporal and economical aspects, because there are great numbers of structures, fewer expert engineers in proportion to number of structures, the said process is economically large-scaled, and it takes too long to determine the structural safety, as well as the fact that it is possible to determine the safety level of a structure by using many parameters. In order to determine the safety levels of structures, it is required to develop fast evaluation methods which are free from any subjective parameters and based on local specifications and compatible with production techniques and practices. In line with this purpose, it is necessary to carry out structural surveys to determine the safety levels of structures by using the parameters, which should be chosen in the minimum basis, but assuring the reliability criteria. The algorithm containing the minimum evaluation criteria, which are essential to evaluate the present condition of structures in accordance with the mathematical bases, and a quick evaluation method featuring the said algorithm are introduced in the presented study. The structural safety of many structures against earthquake effects has been determined fast and correctly by using the developed method.

Completion of the activities within optimal time and cost plays a significant role in construction projects. Recently, project managers have to decrease the total durations and costs of the projects more than before due to the competitive environment. Mostly, decision makers usually seek different alternatives which reduce time and cost. As well as being one of the most major topics of construction management, this problem called time-cost trade-off (TCTO) which is extremely difficult to solve with traditional mathematical methods. In recent years, metaheuristic algorithms are outstanding methods in this field due to their flexible and adaptable structure. This paper presents a new algorithm called F-PSO which consists of hybridizing Firefly Algorithm (FA) with Particle Swarm Optimization (PSO). In this method, the problem is modelled with various execution modes to select the optimal one for each activity. The applicability and validity of the proposed method is confirmed by performing 18-activity project as a benchmark problem. Comparison of numerical results with different metaheuristic algorithms demonstrates the effectiveness and efficiency of F-PSO with regard to optimality of time and cost outcomes.

There is an increasing quest for sustainable development in the built environmental through the use of alternative construction materials. Basalt fibre is one of those materials that is currently gaining interest in concrete production, because it is environmentally friendly, and also has good mechanical features. The current study evaluates the workability, strength properties, impact resistance and hydration characteristics of high strength chopped basalt fibre-reinforced concrete. Basalt fibre was used in varying proportions, and manufactured sand was used as a total replacement of natural fine aggregate, while other natural materials were kept constant, when casting concrete specimens. The results showed that increasing the cut length of basalt fibre could enhance the strength characteristics and impact resistance of concrete. Overall, the study revealed an improved impact resistance in the tested concrete, which could be traced to be a result of rapid hydration.