This paper presents research results diagnosing processes and performance of leading construction firms in Barquisimeto, Venezuela. Studied topics include: constructability application concepts, recognition of constructability barriers, top management recommendations to adopt the methodology, decision making process to lead program consolidation through change management. In addition, several internal aspects relative to construction firm management were analyzed, such as: scheduling and planning, construction difficulties, procurement, personnel characteristics, optimization process and technology implementation.
Rev. ing. constr. [online]. 2008, vol.23, n.1, pp. 04-17. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000100001.
The use of industrial and agricultural waste substitutions for Portland cement has greatly contributed to sustainable development practices. The increase in cement demand will be met by the use of supplementary cementing materials, in order to minimize the clinker consumption. In this study, the effects of silica extracted from rice husk (SRH) as a partial replacement of cement in concretes with low water/binder are reported. The properties investigated include compressive strength, splitting tensile strength, water absorption by immersion, water absorption by capillarity and resistance to chloride ion penetration. The research indicates that SRH is an effective mineral addition for designing durable concrete presenting an optimal performance when the replacement ratio of Portland cement is around 10%.
Rev. ing. constr. [online]. 2008, vol.23, n.1, pp. 18-25. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000100002.
Over the last 10 years an increasing number of companies have implemented lean construction practices in an attempt to improve performance in construction projects. Most companies, and also some researchers, have reported satisfactory results from their implementation. However, there is still a need to provide more extensive analysis of the empirical evidence available to assess the impact of the implementation of lean construction. The authors have researched the implementation of the Last Planner System and other Lean Construction techniques in over one hundred construction projects over the last five years. They have also developed strategies and support tools for implementation. This paper analyzes some of the main impacts observed in the studied projects, and some of the lessons learned from implementations. The paper discusses difficulties and barriers for implementation, productivity improvements, variability reduction and effectiveness of implementation strategies. The paper also provides recommendations for future implementation and research.
An investigation of characterization of a sandy soil mixture with rice husk ash (RHA) and lime is presented. Their objective was to study the physic and mechanic properties of the mixtures, trying to find an economical solution for low-volume transit pavements and to solve an environmental problem like is the deposition of the residual ash from de husk rice burning. The soil was extract in the nearness of Montevideo. A residual RHA of the husk incineration, carried out in an oven of the rice parboilization plant localized in Treinta y Tres City, was used. An analysis of the influence of different mixtures of soil with RHA and lime in the mineralogical composition by x-ray difractograms, optimum compaction parameters, CBR, unconfined compression and split tensile strength and durability is made.
Rev. ing. constr. [online]. 2008, vol.23, n.1, pp. 34-41. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000100004.
In this work, the value is on presenting the results of an application of the model of evaluation of housing project, that it aims at, mainly, to extend and to improve the conditions of analysis of the housing under the perspective of the market. This instrument of evaluation assists the decision-maker to prevent mistakes that generate unnecessary costs in a real estate enterprise. The application of the model enables to identification and the measurement of the satisfaction, of the expectations and the necessities of the user of this sectorand, at the same time, it generates information that can be used during the process of project of housing. The presented model part of the attributes of the physical structure, localization and cost, such as are perceived by the market-target. It consists of the application of standardized procedures that organize and process the information, generating, as result, performance pointers and the unnecessary costs proceeding from elements of the construction, that they do not add value to the housing. These unnecessary costs are on to the functions of the housing perceived by the user.
Rev. ing. constr. [online]. 2008, vol.23, n.1, pp. 34-41. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000100004.
Software VIAS, free versions, allows to make the complete design or a stage anyone within a project of a highway. It has controls easy to use, is in Spanish, and provides clear information, of easy handling and interpretation in addition an excellent presentation. The software can be easily installed in any version of Autocad, the most popular CAD software in the world. It executes completely each one of the stages in a highway design . The horizontal alignment can be made using curved circular or spiral. VIAS software obtains profiles, makes the vertical design, calculates and draws automatically the superelevation, obtains cross sections, calculates the earthwork, affectation of lands and draws the road projected in 3 dimensions. Besides to make the graphical design it provides a complete information in text and Excel files that can easily be manipulated and be incorporated to any report. In addition, it presents some practical applications for survey and GIS.
Rev. ing. constr. [online]. 2008, vol.23, n.1, pp. 52-59. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000100006.