Impacts on ecosystem services, due to human activity, are already a fact. The objectives of Millennium Development Goals (MDGs), the alleviation and adjustment proposals from the Intergovernmental Panel on Climate Change (IPCC) in their consecutive reports, as well as the proposals by the Millennium Ecosystem Assessment (MA) cannot go unnoticed for general projects and for particular construction projects. The amount of waste material generated by the sector, as well as the amount of resources consumed (energy, raw materials) by the whole life cycle (construction, exploitation, maintenance and deconstruction) definitely contributes to increase the human ecological footprint. The goals and requirements for the Integrated Project Management must change. The objective is no longer the achievement of a triple goal (time, costs and quality) and the performance established by the developer. Nowadays there are new sustainability goals and requirements for construction projects. Tools and development techniques are analyzed in the construction field, in order to get a construction achievement in a more sustainable way; and a methodological framework for sustainable management according to standards of Integrated Project Management is proposed.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 147-160. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200001

Both the bid decision and the determination of the bid price are very important to every contractor. The importance of such decisions lies in the fact that, the success or failure of a contractor’s business depends on the outcomes derived from these decisions. The aim of this paper is to identify and analyze the factors which are believed to affect bidding and markup size decisions in the construction industry in Gaza Strip. A questionnaire survey elicited responses from 77 general contractors. The results indicated that, most of the contractors depend on subjective processes in making bid/no bid and markup size decisions are based on experience-based judgment. Some factors are considered important in both decisions while some other factors are considered important in one decision but not the other. The most important groups which affects bid no bid and mark up size were found to be "client and consultant of the project" group, and "project conditions contributing to profitability of the project" group. The results also showed that, the current financial capability of the client, project size and financial status of the company were the main factors affecting bid no bid decisions. Regarding mark up size decision, it was found that the duration of project, political environment, and terms of payment were the main factors affecting the mark up decision. Some recommendations are proposed in this study.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 161-214. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200002

Properties of fresh and hardened concrete are affected by the morphological characteristics of the aggregates. However, there is not an established correlation, between the aggregate shape and the concrete properties, to be taken into account during the mix design process. Conventional aggregate shape measurement methods are subjective, and that is why image analysis has been recently used to determine the morphological characteristics of particles. In this study, the morphological characteristics of coarse aggregates from two different sources are determined using both, conventional methods and image analysis by means of Fourier descriptors. Mechanical properties of concrete prepared with coarse aggregates having different elongation indexes were evaluated. Results indicate that the aggregate shape has little influence in the concrete compressive strength and elastic modulus, while its influence in workability is significant.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 215-240. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200003

Buildability is one of the most important factors affecting labor productivity. Nonetheless, an extensive search of the literature revealed a dearth of research into its effects on in situ reinforced concrete construction, especially at the formwork trade level. Despite the importance of this trade to in situ reinforced concrete material, the influence of buildability factors on formwork labor productivity of major structural elements are yet to be quantified in measurable terms. Grade beams are important structural elements which are primarily used to provide one, or a combination, of the following functions: (1) tie the building foundations to provide the required lateral stiffness at the sub-structural levels; (2) reduce the unsupported free length of columns below grade level; and (3) limit excessive differential settlements of isolated foundations. Therefore, the objective of this research is to investigate and quantify the effects and relative influence of the following buildability factors on formwork labor efficiency of this activity: (a) variability of beam sizes; (b) beam sizes; and (c) number of joints formed at beams intersections. To achieve this objective, a large volume of productivity data was collected and analyzed using the multiple regression method. As a result, the effects and relative influence of the buildability factors investigated are determined. Apart from the variability of beam sizes, the findings show significant effects of these factors on formwork labor productivity, which can be used to provide designers feedback on how well their designs consider the requirements of buildability principles, and the consequences of their decisions on labor efficiency. On the other hand, the depicted patterns may provide guidance to construction managers for effective activity planning and efficient labor utilization.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 241-266. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200004

Business Intelligence Process during recent years have provided a growing number of companies all over the world with the ability to control internal and external environments and to create appropriate know-how for decision making processes; to provide a new Strategic Management orientation; to reduce the potential risk margin and to increase competitiveness. Cuba represents a leading sector of Design and Construction Engineering Companies for the implementation of this new Cuban Management and Business Administration System, seeking to diversify services in the national and international construction market. The purpose of this paper is to demonstrate the use of different tools, such as the expertise calculation index procedure, orientation and information interviews, surveys, category correlation and focus groups, which allowed the diagnosis of initial data situation on the project approach for the implementation of such a process. The most important outcomes were the definition of organization stages to be implemented, by means of a Business Intelligence Project, those elements that limit and facilitate the process. From these elements, an on-going scientific investigation design was created, counting with the cosponsorship from several universities and companies. Concrete results are expected to design a Business Intelligence Process for such companies and a Manual to guide researchers and executive staff involved in the improvement of similar entities of management.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 267-284. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200005

This document presents the analysis of seismic vulnerability and load capacity for Cesar Gaviria Trujilo Viaduct, by means of structural reliability techniques based on instrumentation works. Such study includes: geophysical trial tests, trials tests on material mechanical properties, environmental vibrations, measurements on the effects of traffic load, wireless instrumentation, loading tests, wire strainers tensile strength, etc. Additionally, the study explains structural models on finite elements, which were developed for the bridge, as well as its calibration process based on the loading test, and dynamical properties determined on experimental basis. Furthermore, the study indicates the way stress records collection of all structural elements was conducted, during the construction process, in accordance with the job site log-book. As for reliability, a seismic threat analysis was made as well as dynamic responses on the bridge site, where nine spectrums were obtained at different return periods. By studying strength probability curves and seismic loads of pylons, it was found they have reliability indexes in accordance with recommendations by the international regulations. However, one of the superstructure’s elements, which were introduced to evaluate its capacity on traffic effects, has a reliability index far higher than the ranges recommended by international regulations. Finally, some wire strainers have higher level tensions than specifications admitted during its design and international recommendations for these kinds of bridges.

Rev. ing. constr. [online]. 2010, vol.25, n.2, pp. 285-323. ISSN 0718-5073.  http://dx.doi.org/10.4067/S0718-50732010000200006