This paper describes the development of a method to estimate the quality of work performed by masons in lowincomehousing construction projects. The method described is focused on measuring the level of fulfillment of project'sconstruction specifications in a context where usually quality control standards for construction processes either are notfollowed or do not exist. The method starts assessing standards to qualify the performance of masons. Measuringprocedures included in this method are based on direct observation to identify the level of fulfillment of those standards.These standards were defined for three quality levels (QL) reflecting the fulfillment of project specifications during theconstruction process. With the QL data, weighted quality levels were obtained and applying a Quality-Index-Sampling(QIS) method, the quality indexes (Q) were calculated for each activity. The Quality index is a parameter used to estimatethe percentage of defect (PD), and allows the identification of critical activities that should be taken into account due tonon-fulfillment of project specifications. Benchmarking of two different housing construction projects proved the usefulnessof information obtained through this method to aid the identification of factors affecting on-site labor quality.
One of the most important tasks which public and private agencies must undertake to either preserve or improve the level of service of the existing road network is that of determining the set of projects to be included in the preservation program for the period. In Chile as in most countries, resource allocation for the period is strongly influenced by two aspects: constraints affecting resources that can be allocated and the large number of variables requires for managing the process of evaluating and selecting pavements at network level. Selecting and prioritizing projects at network level requires for a structural and functional evaluation of pavements. Besides, it is necessary to include operating costs during a period under analysis that reflects the life cycle of the pavements. During the investigation, a simplified methodology to select and prioritize those projects having a greater need for maintenance were selected, mathematical formulas to calculate priority were developed, for both asphalt as well as PCC pavements. The priority formulas were developed modeling a group of pavements with different structural and serviceability conditions, evaluating the benefits that users derive from using a road in good serviceability condition. The priority formulas presented a correlation higher than 95%. The scope of the methodology to prioritize is such that it may be used by any agency responsible for a pavement network, without the need of sophisticated computer software.
In Colombia, when a structural review of steel bridges is performed, the design loads, materials specifications andsafety factor are verified as established in the Colombian Code of Bridges Seismic Design (CCDSP). This evaluation is notat all reliable, since it does not bear in mind topics related to structural changes, that could occur due to materials qualityalterations, some element deformation by temperature changes or by the difference in loads that bridges have to support. Ifwe bear in mind that there exists factors of unknown nature that can alter the operation structure, it is necessary to apply anevaluation method that combines stochastic and statistical functions with the structural analysis as the one based onstructural reliability, which shows a bridge's real working conditions. This paper develops the methodology for steelbridges evaluation using structural reliability techniques based on American an European studies, mentioning the maindifferences found during the structural evaluation of Puerto Salgar bridge. The method stated presents the possibility ofprojecting the safety of bridge, which involves a preventive method with big advantage over CCDSP.
This paper describes organizational issues addressed by seven companies in their attempt to introduce “LeanConstruction” practices and techniques in their organizations. Seven Chilean construction companies are currentlydeveloping a collaborative research and implementation effort to improve their competitiveness in the local an internationalmarket. These companies have committed to develop several activities together: a) The implementation of methods toidentify and reduce waste in construction projects, b) The development and implementation of a performance measuringsystem for internal and external benchmarking, and c) Implementation of the “Last Planner” concepts in their projectplanning systems. The paper provides an overview of the research and implementation activities and then focus onorganizational and management issues faced by the companies during this project. The organizational approach of each ofthe companies is described together with their successes and failures, in an early stage of the project. These findings arecompared with others reported in the literature in an effort to identify the ingredients of the most successful strategies.
Construction is a highly risk-prone industry with not a very good track record of coping with risks. The participants in the industry, as a result, have been enduring the agonizing outcomes of failure in the form of unusual delays in project completion, with cost surpassing the budgeted cost and sometimes failed to meet quality standards and operational requirements. Thus, an effective analysis and management of construction associated risks remains a big challenge to the industry practitioners. This paper via, questionnaire survey and in-depth interviews, evaluates the current practices of risk analysis and management adopted by the general contractors in the Florida construction industry and presents the comparison with four other US states considered to have highly profitable and modernized construction industry. The results reveal that in the Florida construction industry, risk analysis and management techniques are rarely used by the general contractors due to a lack of knowledge coupled with doubts on the suitability of these techniques for the construction industry. It is recommended that formal and informal training of general contractors and construction managers is essential to implement such techniques in Florida. This will lead to improved profitability, reduced conflicts and on time and within budget project completions.
The performance relationships developed by the World Bank, mainly those in the HDM-III and HDM-4 models, must be adapted by adjusting certain calibration factors in order to use them in the pavement management system of a country or region. This work presents the results obtained from calibrating the structural cracking models using HDM-4, as well as a comparison with the results obtained from equivalent HDM-III models. This work involved the use of the "windows" methodology, which consists of selecting roads that present similar characteristics (such as traffic, structural capacity and climate) but with different ages, in order to record the distress conditions of each one and in this way to reconstruct the curve of distress. Based on the results of this research, recommendations have been developed for calibrating the performance models, as well as establishing calibration factors for asphalt pavement structural cracking models which are more appropriate for Chilean roads. The results of the comparison of the HDM-III and HDM-4 calibrated models indicate that both yield similar values. Therefore, the HDM-4 cracking models are recommended, due to their operational advantages.
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