Construction industry stands for a very important part of the economy in developed and developing countries. Nevertheless, investment in research, development and innovation (R&D&i) in the construction industry is less than in other economic sectors. This paper addresses R&D&i management in construction as another business process, taking into account the possibility of systematizing R&D&i activities using the set of standards UNE 166000. The literature review delivers an affinity diagram that shows the main ideas regarding innovation in the construction industry. Taking into account these previous concepts, a general model of competitiveness focused in innovation is proposed; finally, a model of R&D&i management for construction companies is also displayed. This model states the need to ease the information flow inside the organization, thus the knowledge generated by innovation in construction sites allows a substantial raise in the business competitiveness. The implementation of a systematic innovation process in construction companies presumes the need to build new organizational hierarchies that differ from the current ones
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 5-14. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100001.
The purpose of the present study was to analyze the performance of reinforced concrete with 28-day compressive strength of 25 MPa and cement content of 300 kg/m³ used in caissons sustaining two wharfs on the Mediterranean coast. The caissons studied are permanently submerged. The preliminary conclusions suggest that whereas the rate of chloride penetration in submerged concrete is much higher than expected, the absence of oxygen offsets the deleterious effects of this development by substantially raising the chloride ion concentration required to initiate corrosion.
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 15-22. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100002.
The traditional construction education model based on precise, well-defined problems and formal definitions is not satisfactorily fulfilling its mission of educating the decision-makers of tomorrow. This realization has moved several researchers to explore alternatives where problem solving is carried out in conjunction with the environment and concepts are embedded in the context promoting learning within the nexus of the activity. Several efforts have been undertaken to develop these environments resulting in a variety of special-purpose situational simulations. However, special-purpose situational simulations exhibit inherent limitations related to their application breadth, flexibility, and promotion of collaborations. These limitations cannot be resolved within the framework of special-purpose learning environments. A general-purpose environment is required to overcome these shortcomings and take full advantage of the situational learning paradigm. This paper presents theoretical aspects related to situational simulation environments as the conceptual framework to introduce a pilot application called Virtual Coach. The implementation and preliminary evaluation of this software system are also discussed in this paper.
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 25-32. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100003.
Based on studies with finite element method, a model able to predict the quantity of steel corrosion (rcrit) necessary for the first visible crack appearance in the surface of the concrete cover was obtained. For the finite element analysis the software ANSYS was used, which has the element SOLID65, with which is possible to model plain concrete, since has the capacity to show crushing in compression and to cracking in tension. The case of the oxide layer is modeled by means of contact elements CONTA174 and the steel with SOLID65, but without the crushing and cracking options. The obtained model is in function of the free cover, diameter of the reinforcement, and concrete type and the longitude of corrosion, known as anodic longitude. The results show the great influence that has the localized corrosion (small-size anode vs large-size cathode) on the prediction of rcrit, and that effect is only possible to analyze it in a three-dimensional way. Likewise, the efficiency of using the contact elements CONTA174 to represent the growth of oxide is shown. The obtained model explains in 92% the phenomenon and which is compared with experimental results found in literature.
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 35-42. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100004.
The quality costs are a quality management tool to measure the continual improvement. It was made a bibliographical revision and discussion of present publications on the generic models of quality costs. It was observed that the most frequently used generic model, continues being traditional approach PAF (prevention, appraisal and failures). So, this model was established in a construction firm context as a quality management tool, pointing out the form in that the effective management of these can be reflected in the utilities and productivity of a construction firm. Also, is suggested that quality costs can be calculated and be recorded in a countable form, providing a parameter to decide on the benefits that its control brings. The objective of a quality costs system is to find the level of quality that minimizes total quality costs; this will give the security that the construction firm is working efficiently in relation to its processes and products.
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 43-56. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100005.
Two different high performance lightweight concretes (HPLC) with strengths of 55 and 69 MPa were developed. They had an air-dry unit weight of 1855 and 1890 kg/m³, respectively. Creep, shrinkage and prestress losses were investigated on 36 cylinder specimens and on four AASHTO Type II girders. Prestress losses measured on the AASHTO Type II girders made with HPLC were less than those predicted using AASHTO, PCI and ACI-209 methods which means that the design codes give conservative estimates of the actual prestress losses of this new concrete. Based on experimental data, final, total prestress losses were estimated to be 14.3 and 9.6% of the initial prestressing force for the 55-MPa and 69-MPa HPLC, respectively
Rev. ing. constr. [online]. 2007, vol.22, n.1, pp. 59-69. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732007000100006.
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