Abstract

The IRI International Regularity Index is a performance indicator that evaluates the functional condition of a pavement structure. Its value is a key input for the management of road assets, allowing to establish the opportune moment for carrying out interventions on the pavement. In addition, it is used to receive road surfaces, assess vehicle operating costs, evaluate the profitability of road projects and establish the cash flow in the financial administration of the project. The IRI data obtained from measurements carried out in the field, feed the deterministic deterioration model that allows future estimations of the indicator and the development of pavement maintenance programs. This research proposes to evaluate in a probabilistic way the model of the IRI International Regularity Index of the HDM-4 program, by assigning probability density functions to the input variables from real data taken in the field. To achieve this objective, a Montecarlo-type simulation model was developed, where roads must be classified by their geographical location, structural capacity of the pavement and traffic intensity expressed in Number of Equivalent Axes. The research results provide the IRI characterized by probability density functions, allowing its estimation from an expected reliability value.

Abstract

Las ondas sísmicas que se transfiere a la cimentación de una edificación causan daños significativos a la estructura ocasionando su deterioro e inestabilidad. El presente artículo exhibe los resultados de someter una estructura a los efectos del sismo y a las propiedades físico – mecánicas del suelo, realizando la comparación de un modelo teórico de apoyo empotrado con el modelo de dinámica estructural de Barkan – Savinov. Se evaluaron tres hipótesis; i) Los efectos negativos causados en las edificaciones planteadas son indirectamente proporcionales, al incremento de las características de la respuesta sísmica que se detectan en los suelos; ii) Las características que presentan los estratos de los terrenos, es directamente proporcional al incremento de las características de la respuesta sísmica de los suelos y iii) El modelo de Barkan – Savinov presenta un rango inferior que el modelo teórico de apoyo empotrado, que simulan una cimentación aplicada en los suelos. Entre sus conclusiones más relevantes se deriva que el modelo de dinámica estructural de Barkan –Savino presenta un rango más específico en las reacciones producidas ante las fuerzas sísmicas y la relación en ambos casos se asevera que es indirectamente proporcional respecto a las características indicadas.

Abstract

This paper introduces a novel non-linear weighting model to evaluate the different aspects of infrastructure. In this regard, three approaches are presented to compute the percents of infrastructure indicators, namely analytical hierarchy process, Shannon entropy and fuzzy set theory. A unified weighting model is then proposed to aggregate the weighting vectors obtained from the three approaches. The developed model is designed to model the feedback of the experts, actual condition of the infrastructure and encountered uncertainties. Results highlighted that water has the highest relative importance with 52.65% followed by electricity with 34.12% while telecommunication has the least relative importance with 2.69%. To apply a more practical sense to the proposed framework, a sample assessment of the Lebanese city of Tripoli’s civil infrastructure was carried out in this paper. The developed model is expected to support planners and policymakers with a platform that enables them to efficiently evaluate the infrastructure’s condition

Abstract

Nowadays, an approximation of the concepts of engineering and art is required, since they are nothing more than modes of expression with which the engineer, like the artist, becomes a maker of form. Beyond the materiality of bridges, dams, or buildings, the engineering work configures a product of sensibility that intellectually provokes the spectator in the same way that conceptual art does, so that the value of engineering must be adjectivized as significant. Just as one cannot claim that art that is recognized as commercial is not art because it has a market value; it is pure reductionism to deny that engineering and art share qualities, beyond its primary function. What both manifestations have in common is significant value, and this is what allows us to unify properties in an attempt to define what can be considered art.

Abstract

Through this paper, three main approaches were adopted to evaluate the effectiveness of waste paper ash (WPA) for stabilization on clay soil. First, the physical properties of mixing soil were studied. Furthermore, the swelling potential of mixing soil with different percentage was also discussed. Finally, the compressive strength using unconfined compressive strength (UCS) apparatus was evaluated. It was found that after mixing with waste paper ash (WPA), the percentage of soil passing sieving number 200 and plasticity index reduces by increasing of the waste paper ash (WPA) percentage. It might be attributed to the bonding of the chemical content of waste paper ash (WPA) to the soil particles. In addition, the swelling potential slightly reduces by increasing of waste paper ash (WPA) percentage. Furthermore, the compressive strength increases with waste paper ash (WPA) 5% and 10%.

Abstract

Scope of study is to evaluate durability characteristics of ferrocement blended geopolymer mortar after subjected to fire. ferrocement element is made of geopolymer mortar and its fire resistance behaviour is compared with the conventional ferrocement element made of cement mortar. Previously, the molar concentration of sodium hydroxide solution used for preparing geopolymer mortar is standardized by finding the residual strength of mortar cubes prepared by various NaOH concentrations. The residual flexural strength of Ferro-geopolymer concrete and normal Ferrocement specimens of various volume fractions (1.5 %, 1.8 %, 2.1%) are exposed to three different temperature levels for two hours from 300 degree Celsius to 900 degrees Celsius are determined and compared. For the same volume fractions, the specimens are exposed to elevated temperature of 900ºc to find the residual impact strength. The fire resisting characters in terms of residual flexural strength, residual impact strength and loss of weight after fire exposure are determined. In all aspects, Ferro-geopolymer concrete shows superior performance than the conventional ferrocement.

Abstract

One of the under-investigated branches of performance design approaches is the design of non-structural elements. Non-structural elements are all those that do not participate directly in the structural resistance of a building, however, they present damage in the event of an earthquake. One of the methods developed in recent years is through direct displacement, which consists of restricting the non-structural element by giving it a maximum allowable displacement and calculating the allowable force by Hooke's law. Therefore, the nonstructural elements for different configurations of a reinforced concrete building were designed using the direct displacement methodology and compared with the design according to the force-based design. Five reinforced concrete buildings (structural wall system) with the same floor were modeled for five different seismic movements and the design was carried out by the two methods for a certain anchoring system. In conclusion, the design based on direct displacement is more efficient than the traditional design, since it considers inelastic parameters. In addition, any non-structural element must be designed by both methods and apply the envelope criteria so as not to violate local regulations.

Abstract

This article evaluates the physical and mechanical properties of a paving block with added ash from artisanal brick kilns in the city of Juliaca to reduce the environmental pollution generated by the ash. For this purpose, data and test results were collected at the GEOCONTROL laboratory in Juliaca. It was designed for a compressive strength of f’c=340 kg/cm2 for type II pavements, adding ash from artisanal brick kilns of 0%, 5%, 10%, 15% and 20% as a partial replacement of cement. Aggregates from the Cabanillas quarry, Portland cement type I and ash from artisanal brick kilns were used as raw materials for the mixture design. From the results obtained, it is concluded that the addition of 5% ash from artisanal brick kilns improves the compressive strength at 28 days of curing. It is important to mention that if the percentage of added ash from artisanal brick kilns increases above 10%, the resistance decreases. Finally, the dimensional tolerance and absorption of conventional paving blocks and additions of 5% ash from artisanal brick kilns meet the established criteria of NTP 339.611.

Abstract

Since 2000 sustainability has become one of the main criteria for assessing and constructing road infrastructure projects. Several methodologies proposed measurements on the pavement's environmental impacts. One of the most relevant is the life cycle assessment (LCA), which estimates emissions generated by each life-cycle stage. A rating system is a tool for decision-making through an environmental rating of a project obtained by applying the best practices in sustainability that could generate impact reductions. This study makes a literature review of methodologies reported in the last years and evaluates the strengths and weaknesses.

Abstract

This document discusses the results obtained in the estimation of compression strength through the readings of the rebound hammer and ultrasonic pulse velocity on 9 columns of reinforced concrete. The estimation was performed by applying different SonReb models. The objective of the study is to evaluate which of the applied models is more consistent with the compression resistance value of 27.0 MPa obtained by press-breaking assay, for concretes manufactured with Ordinary Portland Cements P-35 (Type I) of domestic production and aggregates from Cuban quarries. The results obtained showed that the models proposed by RILEM and Tanigawa et al. were closest to the reference value with percentage difference below 4%. This research will allow the performance of non-destructive tests with more accurate results, in the restoration processes of the Historic Center of Havana, Cuba.

Abstract

Historically, public buildings are not importantly addressed in Brazil, resulting in several buildings dropped to the ruins and unnecessary acquisitions of new spaces by public institutions. The present study was carried out in a building part of the extinct industrial building of the Anglo fridge in Pelotas. The main objective was to evaluate state of degradation state through non-destructive tests in a case study of a public building of Federal Education Institution. Visual analysis, damage map, measurement of nominal coverings, sclerometry tests, silver nitrate spray and phenolphthalein test were performed. The building presents worrying deterioration levels, chlorides, and carbonation presence and several stains moisture. These facts lead concrete detachment, reinforcements corrosion and losses in slabs, beams, and pillars sections.

Abstract

This article addresses the development of a model for the material supply planning and management in the construction industry, using System Dynamics, supported by AHP supplier selection methods, evaluation and monitoring with ABC classification, all mediated by Vensim data analysis software. The supply management in the construction industry is studied and analyzed based on a collaborative model between suppliers and builders, under the CPFR model and the integration of the Last Planner System, which contributes to optimize the use of resources that allow completing all social interest housing (VIS) construction projects. The model simulates the impact and performance produced in the collaborative system, compliance with planning and profitability in VIS projects, appropriate selection, and supplier evaluation and monitoring. Finally, this model allows those who make strategic decisions in VIS projects to identify the most critical variables, assess their contribution, and make the right decisions to eliminate waste due to waiting time.

Abstract

El hormigón es uno de los materiales más usados en la ingeniería civil. No obstante, la industria de la construcción exige el uso de materiales de más livianos y el hormigón celular es una alternativa. Este tipo de hormigón es reconocido por su baja densidad, alta trabajabilidad, baja conductividad térmica y acústica y su alta resistencia al fuego. En estado endurecido, las propiedades del hormigón tales como la densidad, resistencia a la compresión, permeabilidad, retracción y aislamiento termoacústico se encuentran íntimamente relacionadas con su porosidad y distribución del tamaño de sus poros. La diferencia en la estructura de los poros se debe principalmente al tipo de espuma, razón agua-cemento y estabilidad de la espuma. Dada la importancia de la porosidad en la evaluación del comportamiento de un hormigón celular en estado endurecido, este trabajo busca determinar las relaciones matemáticas existentes entre la porosidad, densidad y resistencia a la compresión, considerando el efecto del tipo de reactivo espumante usado y la razón agua-cemento.