One of the key principal goals of pavement asset management is to develop and implement cost-effective pavement construction and maintenance strategies that achieve the required levels of service and performance. A sustainable, cost-effective technique for rehabilitating pavements is foamed bitumen stabilization. This paper presents a study on the performance of foamed bitumen pavements tested in the Canterbury Accelerated Pavement Testing Indoor Facility (CAPTIF), for full scale testing of pavements. Six pavement sections were tested; the variables were bitumen and cement content; one control section with the untreated unbound material was tested. Results showed that surface deflections decreased at sections with higher bitumen contents. After the application of 5,710,000 Equivalent Standard Axles (ESAs), the sections stabilised with cement only, bitumen only, and the control section all showed large amounts of rutting. Conversely, little rutting was observed in the three sections stabilised with foamed bitumen and 1.0% cement, showing that cement and FB together significantly improve pavement performance. The rutting results were used to develop models to describe the stable and unstable performance of the tested pavements. The paper concludes by outlining some of the practical benefits of utilising this technology in pavement asset management.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 05-17. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200001
José Armando Chávez Hernández, Jorge Luis Broche Lorenzo, Carlos A. Recarey Morfa., Fernando Sánchez García, Miguel Angel Maestre Mesa, Noel Pérez Martínez
Exactly in the same spot where the Villa of San Cristóbal of Havana was founded, a monument that looks like a petty temple from Ancient Greece rises: the Templete. This important building of the city has been suffering structural lesions not very common for one with its characteristics, small, of robust texture, adequate materials and good construction, therefore of excellent structural stability. Different interventions have not been able to avoid these structural lesions that appear from time to time. Therefore it became necessary to study the problem using more sophisticated techniques which allowed us to determine its cause. In this paper a description is made of the procedure of pathologic diagnosis followed to identify the lesions and the techniques employed to figure out cause of the problem and to give a definite solution to the lesions found.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 19-33. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200002
Civil projects executors are constantly dealing with the challenge of increasing productivity through resources optimization and their interaction; this has been addressed from different points of view using computational tools and manual tools. This challenge demands also, the implementation of new information technologies and digital tools as an effective strategy to capture reliable data that could contribute to improve the productivity quality and security indicators. This work presents a value generation in construction projects, through the use of new technologies to capture digital information that allows a construction process re-engineering using Lean Construction philosophy and digital simulation. At first, the design and development of an autonomous and programmable module is presented, powered with solar energy, used to capture digital images of construction processes. This system includes hardware and electronic components such as cameras, video cameras, electronic cards, computers, solar panels, web platform and communication systems; all controlled by a specially designed software which simplifies the control of the equipment and its components. This system simplifies the decision-making process regarding the construction methods and the resources involved, in order to minimize the costs and to increase the performance. The results obtained in the implementation of the module in a construction project in Bogota, Colombia, are presented in the second part of this paper. The analysis of the results, the constructive process characterization using Time-Lapse videos and a digital simulation model of the construction process are presented. These results allow reducing cycle times and using better the resources, which is translated into resources savings for the project.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 35-53. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200003
Consistency assessment permits to study road safety regarded to speed. There exist several speed-geometry models that assessed isolated components of roads, which are used for consistency assessment of single elements of roads. For instance, single horizontal curves or reverse curves. Aggregated consistency assessment models, permit to assess long segments of roads.Therefore, continuous speed profiles are needed. In that case, speed-geometry models for single elements are not suitable. Today satellite positioning technology is an efficient way to develop continuous speed profile for long sectors of roads, particularly useful for aggregated consistency assessement. This paper study the Polus' consistency assesment model, which need as input continuous speed profiles. First, Polus' model is discussed. After a method for speed data collection and processing using in-field measurements and models is discussed. Method was applied to 5 roads using a GPS device. Data were processed with Kalman filter and smoothed with loess smoother. With the speed profile processed, filtered and smoothed, Polus' consistency method was used to estimate consistency index in each road. It was concluded that Polus' method and continuous speed profiles are suitables to rate consistency of long road segments. However, special attention should be given to road segmentation to avoid under or over-estimation of the road consistency, particularly in straight and steeped segments.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 55-70. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200004
Among the aspects that influence road accidents, geometric design is the most relevant. The most used method for evaluating the design all over the world is based on the design consistency with speed profile models of operation. Cuba does not have proprietary models that consider the characteristics of the roads and drivers, so it is necessary to develop predictive models for the evaluation of design consistency. The development of operating speed profile prediction models for different alignment conditions on rural roads with two lanes in the context of Cuba is made from the geometric characteristics and point speeds with statistical analysis of the main variables related with the operating speed. Once models are developed they are applied to a sectíon of road designated as an accident concentration section (TCA) of the province of Villa Clara located in central Cuba, these results confirm the validity of the models developed to determine the operating speeds, thus evaluating the design consistency, with the aim of detecting the locations of greater difficulties with respect to the geometric design.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 71-82. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200005
The purpose of this paper is to investigate how the knowledge of real estate market can be used to support user requirement identification. A construction project well adjusted to the user requirements increase value and causes minors changes during its life cycle. As a consequence, renewal, refurbishments, and demolition are less present, reducing waste generation, reworking and material consumption. It is especially important in housing customization markets. However, one of the challenges faced by designers is frequently concerned about how properly to identify user requirements, wishes and needs, which is on the essence of the briefing phase. In this context, real estate data can be useful to designers, since it reflects the users’ evaluation of the building attributes. The research strategy uses a knowledge discovery mechanism, composed by five steps: (1) formulation of a general database; (2) specific data selection using Case-Based Reasoning; (3) enrichment of data-sample; (4) development of hedonic price models using regression analysis; and (5) simulation of the value of design alternatives. Based on an application of an hedonic price model, using data from the medium-class housing market of Porto Alegre, Brazil, the main results indicate that adjusted price models have sufficient detailing and statistical precision to support decisions in the initial stage of design.
Rev. ing. constr. [online]. 2012, vol.27, n.2, pp. 83-98. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732012000200006
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