Permanent deformation of asphaltic mixtures in the Metropolitan Area of Valle de Aburra – Antioquia, which are built under IVIAS’ specifications (Instituto Nacional de Vías) and Valle de Aburrá, were studied by employing a constitutive model proposed previously. This model had proved to be effective in predicting deformations of asphaltic mixtures in the United Kingdom under different kinds of loads; under uniaxial and triaxial conditions and temperatures at intervals between 0 ºC and 40 ºC. For the specific case of Valle de Aburra, temperatures ranged between 20 ºC and 50 ºC and the model was implemented in order to predict susceptibility to permanent deformation. By means of an experimental study on mixtures, it was found that their behavior under steady state condition followed the model modified by Cross2, thus mixtures showed a visco-linear and non-linear behavior at low and high stress levels, respectively. It was observed that under loading and unloading conditions, there is a temperature dependence on the material behavior, which was properly predicted by Arrhenius3 under the studied temperatures interval. When modeling mixtures behavior, it was found that that their strain susceptibility varied widely depending on the constituent materials, especially on the aggregate, in spite of the fact that the mixtures are similar.
Rev. ing. constr. [online]. 2011, vol.26, n.2, pp. 128-149. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732011000200001
The paper presents a review of the Bogota bike-path network management system. The results of the study showed that it is necessary to establish a specific manual for bicycle paths with the potential damage in such structures. The prediction of the distress on the bike paths requires the definition of monitoring sections to feed a database that allows the development of empirical models. The document proposed key elements that must contain an infrastructure management system, such as: models for deterioration development, definition of maintenance standards and social assessment at the stage of prioritizing interventions. These factors should be considered to structure a future version of the bike-path management system. The results of the study showed different topic that must be improved and developed, such as; the definition of a comfort index to bike-path user and the necessity of establishing a maintenance guidebook.
Rev. ing. constr. [online]. 2011, vol.26, n.2, pp. 150-170. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732011000200002
The first part of this research shows that in the works of shafts and tunnels construction, incidents and accidents are mostly caused by factors involving directly the workers behavior, even when the work safety conditions have been provided completely. The research is based on the data collected during two years in the construction of a deep drainage system in the Mexico City, which was carried out by four major Mexican construction companies. This research was developed from by external project monitoring, which allows using representative data without the problem of affect or benefit participating companies. Considering that the construction of the project will require three more years, the second part of the research aims to develop and implement a plan of labor risks prevention (LRP) based on the behavioral intervention of workers, in order to minimize the presence of accidents at work.
Rev. ing. constr. [online]. 2011, vol.26, n.2, pp. 171-186. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732011000200003
This paper proposes a methodology for estimating greenhouse gas emissions from road traffic. The method uses information about the cities and their growth estimates in order to model traffic by using a gravity model. These kind of mathematical models allow study the number of trips “originated in” or “destined for” a particular area and distribute them to calculate the greenhouse gases emissions from these trips. In this way the information regarding these emissions can be used in urban planning phase and preventive and compensatory measures can be included in these processes.
Rev. ing. constr. [online]. 2011, vol.26, n.2, pp. 187-207. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732011000200004
This work presents some experiences in producing building materials, such as clay bricks, from an alternative energy source that replaces wood or firewood by waste lignocellulosic material submited to the process of densification under low pressure. The densification process at low pressure involves the use of a binder; this paper proposes the use of clay material as binder. The main objective of this study was to evaluate the effect in the consumption of biofuel during the production of handmade bricks, partially replacing wood by densified biomass. Some properties of the biofuel are identified to increase the bricks-to-fuel consumption ratio from 1.1 to 1.4. This improves the efficiency of the production process, reduces specific consumption regarding the use of traditional fuels with its consequent environmental improvement of the process.
One of the most important parameters to define bituminous mixture behavior in service is the toughness that the bitumen provides when binding the aggregate particles; that is; the dissipated energy during the materials fracture process. The greater the dissipated energy in fracture, the better the bituminous mixture quality is. Hence, a relationship will have to exist if the toughness is removed during one load cycle (direct tension) or during many cycles along time (fatigue). The purpose of this study is to determinate relationships between the toughness of different bitumens and the fatigue behavior of their corresponding bituminous mixtures, for which, the toughness has been obtained by means of direct tension test and has been compared with the value of the fatigue law and dissipated energy obtained by fatigue bending test. Results showed that, this study expect to give important means for further research to predict fatigue life from a static test.
Rev. ing. constr. [online]. 2011, vol.26, n.2, pp. 224-239. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732011000200006
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