Resumen La estabilización con cemento hidráulico de materiales granulares para bases y subbases, es un proceso muy utilizado en la construcción de pavimentos debido a sus grandes ventajas y aportes estructurales. En la actualidad, ha surgido la necesidad de desarrollar métodos constructivos novedosos que contribuyan a la sostenibilidad del medio ambiente y reduzcan los costos constructivos de la red vial. En este trabajo se analizaron dos materiales granulares diferentes, uno que cumple con las características solicitadas por la normativa costarricense (CR-2020) para ser considerado en la construcción de capas de base estabilizada y otro que no. En estos se agregaron distintos porcentajes de fibras sintéticas de tereftalato de polietileno (PET) reciclado para determinar si mediante esta adición se puede disminuir la cantidad del material cementante requerido, con el fin de reducir costos en el proceso constructivo de bases estabilizadas y, por otro lado, para analizar si es posible obtener las resistencias a la compresión mínimas requeridas por la normativa utilizando otro material granular que no está destinado para tal fin. Utilizando diferentes porcentajes de cemento tipo MM/C (C-P)-28 con los dos materiales granulares, se fabricaron cilindros para una muestra patrón (sin PET) y también para muestras con varios porcentajes de adición de fibras recicladas de PET. A partir de una evaluación mecánica, se obtuvieron resultados positivos en los que se pudo observar que, mediante esta adición de fibras, se puede reducir la cantidad de material cementante inclusive por debajo del mínimo permitido por la normativa costarricense vigente (3 %) sin comprometer la resistencia a la compresión. Por ejemplo, durante la investigación se observó que al utilizar un 2,5 % de cemento en los materiales granulares con adición de fibras sintéticas de PET, se obtuvo una resistencia a la compresión promedio de 3,33 MPa, la cual se encuentra sobre el mínimo permitido de 3,0 MPa.

Abstract Stabilization of granular materials for bases and subbases with hydraulic cement is a process widely used in pavement construction due to its great advantages and structural contributions. Currently, the need has arisen to develop novel construction methods that contribute to environmental sustainability and reduce the construction costs of the road network. In this research, two different granular materials were analyzed, one that complies with the characteristics required by Costa Rican standard (CR-2020) to be considered in the construction of stabilized base layers, and other that doesn't. Different percentages of recycled polyethylene terephthalate (PET) synthetic fibers were added to these materials to determine whether the addition of PET can reduce the amount of cementitious material required in order to reduce costs in the construction process of stabilized bases, and, on the other hand, to analyze whether it is possible to obtain the minimum compressive strengths required by the standards by using another granular material that is not intended for that purpose. Using different percentages of cement type MM/C (C-P)-28 with the two granular materials, cylinders were manufactured for a standard sample (without PET), and for samples with various percentages of recycled PET fibers. From a mechanical evaluation, positive results were obtained in which it was possible to observe that, through this addition of fibers, the amount of cementitious material can be reduced even below the minimum allowed by current Costa Rican standard (3 %) without compromising the compressive strength. For example, during the investigation it was observed that by using 2,5% cement in the granular materials with the addition of synthetic PET fibers, an average compressive strength of 3,33 MPa was obtained, which is above the minimum allowed of 3,0 MPa.

Resumen La rehabilitación de pavimentos deteriorados requiere de diversos recursos tanto naturales como económicos. Ante tal problemática esta investigación tuvo como objetivo elaborar un diseño de mezcla para la estabilización de un suelo reciclado con emulsión asfáltica tipo CSS-1h, utilizando el método de diseño Marshall modificado. El estudio analizó la influencia del porcentaje de emulsión asfáltica (3,0 % a 6,0 %) respecto a las propiedades físicas y mecánicas del suelo estabilizado según los parámetros que exige el manual peruano de carreteras EG-2013. Los resultados muestran que, con una dosificación de 4,8 % de emulsión asfáltica y 2,88 % de residuo asfáltico se logra el mejor comportamiento en comparación a los demás porcentajes planteados, obteniendo una máxima estabilidad de 980 kg superando el mínimo valor de 227 kg establecido por la norma. Se concluyó que con dicha dosificación se obtiene una mezcla asfáltica estable con la que se puede estabilizar el pavimento deteriorado para soportar un tránsito vehicular mediano.

Abstract The rehabilitation of deteriorated pavements requires various natural and economic resources. Given this problem, this research aimed to elaborate a mix design to stabilize recycled soil with asphalt emulsion type CSS-1h, using the modified Marshall design method. This study analyzed the influence of the percentage of asphalt emulsion (3,0 % to 6,0 %) regarding the physical and mechanical properties of the stabilized soil according to the parameters required by the Peruvian road manual EG-2013. The results show that with a dosage of 4,8 % of asphalt emulsion and 2,88 % of asphalt residue, the best performance is achieved compared to the other percentages proposed, obtaining a maximum stability of 980 kg, exceeding the minimum value of 227 kg established by the regulations. It was concluded that with the aforementioned dosage a stable asphalt mixture is obtained with which the deteriorated pavement can be stabilized to withstand medium vehicular traffic.

Resumo O crescimento da quantidade de resíduos provenientes da indústria e do meio urbano tem motivado a realização de pesquisas visando o seu aproveitamento em obras de infraestrutura. No estado brasileiro do Rio Grande do Norte ocorre a exploração do mineral scheelita, que é fonte de obtenção do raro elemento químico tungstênio, que apresenta importantes aplicações industriais. O seu processo de beneficiamento provoca uma elevada geração de resíduos e danos ambientais decorrentes da formação de pilhas de resíduos. Assim, nesse contexto, o presente trabalho apresenta uma análise do aproveitamento dos resíduos da mineração de scheelita associados a três tipos de solos provenientes de jazidas de três regiões do estado do Rio Grande do Norte. Com base em dados de análises granulométricas desses materiais, foram analisadas misturas com incrementos de 20%, 40% e 60% de resíduos de scheelita, em massa, associados aos três solos. Os resultados mostraram que a mistura com melhor composição granulométrica para camadas de base de pavimentos é composta pelo solo mais grosso entre os solos avaliados com 20% de resíduo, conforme normas internacionaisda AASHTO e ASTM econforme norma nacional do DNIT.

Abstract The growth in the amount of waste from the industry and the urban environments has motivated the realization of research aimed at its use in infrastructure works. In the Brazilian state of Rio Grande do Norte the scheelite mineral is exploited, which is a source for obtaining the rare chemical element Tungsten, which has important industrial applications. Its beneficiation process causes a high generation of waste and environmental damage resulting from the formation of waste piles. Thus, within this context, the present work presents an analysis of the use of scheelite mining waste associated with three types of soils from deposits in three regions of the state of Rio Grande do Norte. Based on data from particle size analysis of these materials, mixtures with increments of 20%, 40% and 60% of scheelite waste, by mass, associated with the three soils, were analyzed. The results showed that the mixture with the best granulometric composition for pavement base layers is composed of the coarsest soil among the soils evaluated with 20% waste, according to international standards of AASHTO and ASTM, and according to the national DNIT standard.

Resumen El fenómeno subsidencia ocasionado por la sobreexplotación excesiva de algunos acuíferos para el abastecimiento de agua potable, ha provocado la aparición de agrietamientos y asentamientos diferenciales en los pavimentos, repercutiendo en un sin número de daños en las vías terrestres en diferentes estados de la República Mexicana y del mundo. En efecto, la tecnología ha progresado y de esta manera se han incorporado nuevas técnicas para acelerar la solución a este tipo de problemas como el Vehículo Aéreo No Tripulado (VANT) y el Sistema de Posicionamiento Global (GPS); estas tecnologías han influido en distintas tareas como: a) levantar grandes áreas en periodos pequeños, b) disminuir el alto requerimiento de personal y c) la poca demanda de los recursos necesarios para cubrir las necesidades de uso. Esta investigación presenta una metodología para la medición de los agrietamientos en pavimentos con la finalidad de acelerar el proceso de identificación y predicción de asentamientos en un área, misma que presenta continuos movimientos por subsidencia desde hace años, provocando cuantiosos daños en la infraestructura existente. Se consideró monitorear el área por doce meses, obteniendo un ortomosaico y cinco Modelos Digitales de Elevación (MDE) cada dos meses y procesando mediante softwares especializados en fotogrametría VANT usando Puntos de Control Terrestres (GCP o BN) para poder corregir los MDE mediante la ortorectificación de las fotografías. Los resultados obtenidos muestran cómo se reduce el tiempo de identificación de daños en los pavimentos, asimismo, se han obtenido asentamientos de magnitud con 5.7 cm en el área, además de un procesamiento de datos de dos horas cubriendo un área de 27,224 m2. De la misma manera, con este procesamiento es posible conocer un valor más aproximado, se han podido medir la longitud y ancho de las grietas por la relación GSD (cm/pix) que es programada en el vuelo del VANT.

Abstract The subsidence phenomenon caused by the excessive overexploitation of some aquifers for the supply of drinking water, has caused the appearance of cracks and differential settlements in the pavements, affecting countless damages to land roads in different states of the Mexican Republic and of the world. Indeed, technology has progressed and thus new techniques have been incorporated to speed up the solution to these types of problems, being: the Unmanned Aerial Vehicle (UAV) and the Global Positioning System (GPS); These technologies have influenced different tasks such as: a) raising large areas in small periods, b) reducing the high requirement of personnel and, c) the low demand for the resources necessary to cover the needs of use. This research presents a methodology for the measurement of cracks in pavements in order to speed up the process of identification and prediction of settlements in an area, which has had continuous movements due to subsidence for years, causing extensive damage to existing infrastructure. It was considered to monitor the area for twelve months, obtaining an orthomosaic and five Digital Elevation Models (DEMs) every two months and processing through specialized UAV photogrammetry software using Ground Control Points (GCP or BN) in order to correct the DEMs through orthorectification. of the photographs. The results obtained show how the time to identify pavement damage is reduced, likewise, settlements of a magnitude of 5.7 cm have been obtained in the area, in addition to a two-hour data processing covering an area of 27,224 m2. In the same way, with this processing it is possible to know a more approximate value, it has been possible to measure the length and width of the cracks by the GSD ratio (cm/pix) that is programmed in the UAV flight.

La utilización de materiales no convencionales ha sido una técnica ampliamente estudiada y utilizada en el mundo. Se reporta los resultados del análisis comparativo desde el punto de vista técnico y económico de una mezcla densa en frío con la adición de asfaltita. El diseño se realizó por las metodologías Marshall y Ramcodes, previa caracterización de los agregados, esto con el fin obtener puntos de comparación en el cumplimiento de las especificaciones y propiedades volumétricas obtenidas y determinar si la asfaltita puede ser utilizada en la construcción de capas de estructuras de pavimentos flexibles en nuestro país. La mezcla diseñada con asfaltita, para la gradación del límite central de las especificaciones, cumple los criterios de diseño para una mezcla densa en frio usada en labores de bacheo, con excepción del flujo. Estas mezclas, pueden llegar a tener un mejor comportamiento que las mezclas convencionales, a un costo no muy alto. Es prometedor el uso de las asfaltitas de Pesca Boyacá, como agregado fino en una mezcla densa en frio con emulsión asfáltica, una vez que aumenta su estabilidad a un costo de fabricación inicial, inferior al costo de una mezcla convencional.

The use of unconventional materials has been a widely studied and used technique around the world. The results of the comparative analysis of a dense cold mix of aggregates with the addition of asphaltite from a technical and economic point of view is reported. The study was carried out using the methods developed by Marshall and Ramcodes, which characterized the aggregates first, in order to make an accurate comparison between the specifications and volumetric properties obtained and determine if asphaltite can be used in the construction of layers of flexible pavements in Colombia. The mix designed for the gradation of the central limit of the specifications using asphaltite meets the design criteria for a cold dense mix used in patching work except for flow. These mixtures can have a better performance than conventional mixtures while remaining economic. The use of Pesca, Boyacá asphaltites as a fine aggregate in a dense cold mix with asphalt emulsion is promising. This is due to its increased stability at an initial manufacturing cost which is lower than the cost of a conventional mix.

RESUMEN Objetivo: Esta investigación presenta una novedosa metodología multicriterio que permite evaluar dos materiales asfálticos utilizados en el sector de la pavimentación, en aras de aportar directrices al momento de seleccionar un material bajo un perfil sostenible. Esta herramienta metodológica permite evaluar características e indicadores asociados al comportamiento de una mezcla asfáltica de forma integrada, consistente y con impacto medioambiental. Metodología: Se obtuvo un parámetro de sostenibilidad asociado al estudio de dos materiales del sector de la pavimentación. Se evaluaron las principales características de una mezcla asfáltica en caliente y una mezcla fría bajo las mismas condiciones de contorno. Con respecto al modelo multicriterio, se tomó el concepto de teoría de la decisión, con apoyo de la metodología MIVES y la función de utilidad, permitiendo evaluar y comparar los indicadores propuestos para este caso de análisis. Resultados: Se obtuvo el índice de sostenibilidad para los dos materiales estudiados. La mezcla asfáltica fría obtuvo un valor de 0,76, representando de forma global un mejor desempeño en los tres ejes analizados (medioambiental, económico y de operación). Por otro lado, la mezcla en caliente obtuvo un índice de 0,57, valor inherente a una respuesta menos positiva que la mezcla fría. Conclusiones: La metodología desarrollada permitió incorporar variables e indicadores con unidades de medición distintas y de naturaleza diversa. La obtención de un índice de sostenibilidad en materiales asfálticos supone un avance significativo en la aplicación de metodologías multicriterio.

ABSTRACT Objective: This research presents a novel multi-criteria methodology that allows evaluating two asphalt materials used in the paving sector, aiming to provide guidelines for selecting a material under a sustainable profile. This methodological tool allows evaluating characteristics and indicators associated with the behavior of an asphalt mixture in an integrated and consistent way as well as with environmental impact. Methodology: A sustainability parameter associated with the study of two materials from the paving sector was obtained. The main characteristics of a hot asphalt mixture and a cold mixture under the same contour conditions were evaluated. Regarding the multi-criteria model, the concept of decision theory was taken, supported by the MIVES methodology and the utility function, thus allowing to evaluate and compare the indicators proposed for this analysis case. Results: The sustainability index was obtained for the two materials studied. The cold asphalt mixture obtained a value of 0,76, representing an overall better performance in the three axes analyzed (environmental, economic, and operation). On the other hand, the hot mixture obtained an index of 0,57, a value inherent to a less positive response than the cold mixture. Conclusions: The developed methodology allowed for the incorporation of variables and indicators of different units of measurement and diverse nature. Obtaining a sustainability index in asphalt materials represents a significant advance in the application of multi-criteria methodologies.

Resumo O uso de polímeros na indústria está em expansão, principalmente o de polímeros reforçados com fibra de vidro (PRFV). Na produção de peças com PRFV, inevitavelmente, são geradas quantidades significativas de resíduos, que carecem de destino em aterros industriais, o que representa um custo para o setor industrial e um problema ambiental. A busca por soluções que possam incorporar esses resíduos no processo ou como substituinte de matérias-primas é um dos focos atuais de pesquisas na área de materiais. Assim, este estudo avaliou a aplicação do resíduo de PRFV em misturas de concreto para a produção de peças para pavimento intertravado. O resíduo apresentou granulometria de agregado miúdo, com módulo de finura de 1,71. A morfologia revelou haver uma superfície heterogênea, com grânulos de diferentes tamanhos e bastonetes alongados lisos. A substituição parcial da areia pelo resíduo de PRFV (5%, 10% e 15%) resultou em peças com menor resistência à compressão (< 31 MPa) quando comparadas ao controle, sem PRFV. Entretanto, os resultados de resistência permitem a aplicação dos pavers em lugares com tráfego leve ou mesmo em calçadas, com a vantagem de a peça ser mais leve.

Abstract The use of polymers in industry is expanding, especially glass fiber reinforced polymers (GFRP). The production process of GFPR parts generates significant amounts of waste, which then needs to be disposed of in industrial landfills, which both generates financial costs for the industrial sector and constitutes an environmental problem. The search for solutions that incorporate the waste either in the process or as a substitute for raw materials is one of the current concerns of research into materials. This study evaluates the application of GFRP waste in concrete mixtures for the production of interlocking pavers. The waste presented fine aggregate granulometry, with a fineness modulus of 1.71. The morphology revealed a heterogenous surface, with granules of different sizes and smooth and elongated stems. The partial replacement of sand by GFRP residue (5%, 10% and 15%) resulted in pavers with lower compressive strength (< 31 MPa) when compared to the control specimens without GFRP, however, the strength results allow the application of pavers in places with light traffic or on sidewalks, with the advantage that these pavers are lighter.

resumo: Neste trabalho os autores têm por objetivo investigar uma metodologia para determinação dos pavimentos ótimos ao implementar outriggers (ORs) e belt-trusses (BTs) ao longo da altura de um edifício alto para reduzir tanto o máximo deslocamento lateral (MDL), quanto o momento na base do núcleo (MBN), de forma separada e concorrente. Além disso, analisa-se a influência destes elementos sobre outros critérios como a máxima aceleração e as frequências naturais. Ao longo do trabalho verifica-se o comportamento da estrutura quando a relação de rigidez dos principais elementos do sistema de contraventamento (núcleo, colunas perimetrais, OR e BT) são variados. Sendo assim, um modelo tridimensional de um edifício alto sob ação lateral de vento é analisado, empregando o método dos elementos finitos usando o software ANSYS. As otimizações mono e multiobjetivo foram resolvidas, respectivamente, pelo método Nelder-Mead modificado para variáveis inteiras pelos autores e pela função de utilidade. Diante dos resultados, conclui-se que ao introduzir de forma específica os ORs/ORs-BTs em edifícios altos a influência na redução dos objetivos mencionados é extremamente relevante, podendo chegar a 68% para o MBN e 71% para o MDL, dependendo de suas quantidades empregadas.

abstract: This paper aims to investigate a methodology for determining the optimum floor positioning of outriggers (ORs) and belt-trusses (BTs) over tall buildings height. The primary goal is to reduce the maximum lateral drift (MLD) and the core base moment (CBM), individually and concurrently. Furthermore, the influence of these elements on other criteria such as maximum acceleration and natural frequencies are analyzed. Throughout the work, the behavior of the structure is verified when the stiffness ratio of the main elements used in the bracing system (core, perimeter columns, OR, and BT) are varied. Therefore, a three-dimensional model of a tall building under lateral wind load is analyzed, using the finite element method with ANSYS software. The mono and multi-objective optimizations were solved, respectively, by the Nelder-Mead method with the author’s modifications to deal with integer variables and by a utility function. Based on the results, it is concluded that by specifically adding ORs/ORs-BTs in tall buildings the influence on the reduction of the mentioned objectives is extremely relevant, reaching up to 68% for the CBM and 71% for the MLD, depending on the amounts employed.

resumo: Este trabalho apresenta um estudo comparativo da influência de pilares-parede no comportamento de um edifício de concreto de vários andares quando submetido a ações sísmicas. Foram avaliadas duas estruturas com diferentes sistemas sísmicos. Uma é composta por pórticos de concreto com detalhamento usual em ambas as direções (x e y), e a outra é formada por um sistema dual, composto por pórticos e pilares-parede com detalhamento usual. Os Métodos das Forças Horizontais Equivalentes e Espectral apresentados pela norma técnica brasileira ABNT NBR 15421:2006 foram considerados. Verificou-se que a edificação de sistema dual apresentou maior rigidez com os pilares-parede dispostos paralelamente à direção y. Na direçãox, as respostas são equivalentes em ambos os edifícios. Os esforços horizontais obtidos pelo método das forças equivalentes na base dos edifícios foram maiores que os espectrais.

abstract: This paper presents a comparative study of the influence of shear walls on the behavior of a multi-storey concrete building when subjected to seismic actions. Two structures with different earthquake-resistant systems were evaluated. One is composed of concrete frames with usual detailing in both directions (x and y), and the other one is formed by a dual system, composed of frames and shear walls with usual detailing. The Equivalent Lateral Force procedure and the Modal Response Spectrum analysis presented by the Brazilian Technical Code ABNT NBR 15421:2006 were considered. The dual system building presented a greater stiffness with the shear walls arranged parallel to direction y. In the x direction, the responses are equivalent in both buildings. The horizontal forces obtained by the Equivalent Lateral Force method at the base of the buildings were greater than the Modal Response Spectrum method.

RESUMO Este trabalho consiste na avaliação do comportamento mecânico, em especial da vida de fadiga, de algumas misturas asfálticas tradicionalmente utilizadas no estado de Goiás, Brasil. Para a preparação das amostras, a granulometria dos agregados foi definida por meio da metodologia Bailey e em seguida verificada pela Fração do Agregado Dominante (FAD). Além dos ensaios de fadiga, outros ensaios laboratoriais foram realizados para avaliação do comportamento mecânico das misturas. Os resultados obtidos nesta pesquisa indicaram que somente a seleção granulométrica a partir da metodologia Bailey não foi suficiente para que as mistura estudadas apresentassem melhorias quanto à deformação permanente, sendo necessário, portanto, a análise da porosidade FAD bem como da realização de ensaios mecânicos como o ensaio uniaxial de carga repetida para determinação do Flow Number. As misturas estudadas apresentaram bom comportamento quanto à fadiga se enquadrando na Classe 4 da metodologia utilizada no software brasileiro de dimensionamento de pavimentos (MeDiNA). Assim, constata-se que quanto à fadiga, as misturas estudadas podem ser consideradas satisfatórias. No entanto, em termos de deformação permanente elas não apresentaram o desempenho necessário, sendo que a adequação granulométrica baseada apenas na metodologia Bailey não foi suficiente para melhorar o Flow Number. A partir desses resultados, recomenda-se que a faixa indicada para o FAD seja atendida e que outros tipos de ligantes asfálticos sejam incorporados nessas misturas para obter melhor desempenho.

ABSTRACT This paper consists in the evaluation of asphalt mixtures regarding their mechanical behavior, especially the fatigue life of some asphalt mixtures traditionally used in the state of Goiás, Brazil. For sample preparation, the grain size distribution of the aggregates was defined using the Bailey methodology and then checked by the Dominant Aggregate Size Range (DASR). Besides the fatigue tests, other laboratory tests were performed to evaluate the mechanical behavior of the mixtures. The results obtained in this research were able to demonstrate that only the particle size selection from the Bailey methodology was not enough for a given mixture to present improvements in terms of permanent deformation. Therefore, analysis of the DASR porosity as well as mechanical tests such as the uniaxial repeated load test for determination of the Flow Number were necessary. The studied mixtures presented good fatigue behaviour and fit in Class 4 of the methodology used in the Brazilian design software (MeDiNA). Thus, this study points that for fatigue performance, the studied mixtures can be considered satisfactorily. However, in terms of permanent deformation they do not showed the necessary behavior, and the grain size adjustment based only at the Bailey method was not enough to improve the Flow Number. From these results, it is recommended that the DARS porosity range must be considered and other types of asphalt binders be incorporated into these mixtures to achieve their best performance.

Resumen La demanda del uso de pavimentos flexibles va creciendo raudamente debido a su buen desempeño, pero este está siendo afectado de manera considerable debido al aumento del tráfico y las variaciones climáticas, esto trae consigo la presencia de fallas considerables en el pavimento, causando que su desempeño disminuya y por ende se acorte su tiempo de vida útil. Este documento tiene como objetivo realizar una revisión sistemática de los distintos tipos de fibras usados en las mezclas asfálticas para la mejora de sus propiedades mecánicas, además de estudiar los porcentajes y longitudes óptimas, las pruebas utilizadas, el desempeño de las mezclas según el tipo de betún, el tipo de mezcla asfáltica, y finalmente se revisa la rentabilidad que proporciona el uso de fibras en las mezclas asfálticas. Se revisaron 81 artículos publicados en las bases de datos de Scopus y Ebsco, entre los años 2014 al 2021, los cuales tuvieron el mismo objetivo de estudiar las características mecánicas de las mezclas asfálticas con adición de fibras. Se concluyó que las fibras además de mejorar las propiedades de los pavimentos flexibles son rentablemente buenas, ya que a pesar de tener un aumento en el costo inicial demuestran un incremento en el ciclo de vida, siendo así económicamente factibles para proyectos viales que se realicen con el uso mezclas asfálticas, además se recomendó proseguir con estudios encaminados a utilizar este tipo de mezclas asfálticas.

Abstract The demand for the use of flexible pavements is growing rapidly due to its good performance, but this is being affected considerably due to increased traffic and climatic variations, this brings with it the presence of considerable failures in the pavement, causing its performance decrease and therefore its useful lifetime is shortened. This document aims to carry out a systematic review of the different types of fibers used in asphalt mixtures to improve their mechanical properties, in addition to studying the optimal percentages and lengths, the tests used, the performance of the mixtures according to the type of bitumen, the type of asphalt mix, and finally the profitability provided by the use of fibers in asphalt mixes is reviewed. Eighty-one articles published in the Scopus and Ebsco databases were reviewed, between 2014 and 2021, which had the same objective of studying the mechanical characteristics of asphalt mixtures with the addition of fibers. It was concluded that the fibers in addition to improving the properties of flexible pavements are profitably good that despite having an increase in the initial cost, they demonstrate an increase in the life cycle, thus being economically feasible for road projects that are carried out with the use flexible pavements, it is also recommended to continue with studies aimed at using this type of asphalt mix.

Resumen La presente investigación se basó en la innovación y elaboración de una mezcla asfáltica en caliente (MAC), debido al deterioro prematuro de los pavimentos flexibles, y poca capacidad de cumplir con su vida útil. He aquí la necesidad de asegurar una buena calidad de materiales para la mezcla asfáltica y una búsqueda de nuevo material que sea capaz de dar mayor durabilidad y evitar un prematuro deterioro del pavimento. Se evaluó así la incorporación de escoria de acero para el diseño de MAC, con el objetivo de determinar la estabilidad y flujo de la mezcla asfáltica en caliente incorporando escorias de acero. Para esto, se empleó la metodología Marshall con un porcentaje de escoria de acero respecto al agregado grueso en 0% - 15% - 25% - 50% - 75%. Los resultados obtenidos, en cuanto a calidad de los agregados, cumplieron con los estándares de calidad. Se concluyó que la mezcla asfáltica modificada con la escoria de acero al 15% es la mejor combinación, de igual forma, este porcentaje cumple para tránsito liviano, mediano, al 25% - 50% - 75% solo cumplen para transito liviano. Se logró aumentar la estabilidad y flujo de la mezcla asfáltica al incorporar hasta un máximo de 25% para una MAC respecto a la mezcla de control.

Abstract The present investigation was based on the innovation and elaboration of a hot asphalt mix (HMA) due to the premature deterioration of flexible pavements, and low capacity to fulfill its useful life. Then, it is recognized the need to ensure a good quality of materials for the asphalt mix and a search for a new material that can give greater durability and avoiding premature deterioration of the pavement. Thus, the incorporation of steel slag for the HMA design was evaluated with the objective to determine the stability and flow of the hot asphalt mixture incorporating steel slags. To achieve this, the Marshall methodology was developed with a percentage of steel slag with respect to the coarse aggregate in 0 % - 15% - 25% - 50% - 75%. The results obtained, in terms of quality of the aggregates, complied with the standards of quality. It was concluded that the modified asphalt mixture with 15% steel slag is the best combination, in the same way this percentage complies for light-medium traffic, the remaining combinations (25% - 50% - 75%) only comply for light traffic. It was possible to increase the stability and flow of the incorporated asphalt mixture up to a maximum of 25% for a HMA-2 with respect to the control mixture.

Resumen El factor camión es uno de los principales factores dentro de la estimación de la demanda de cargas que tendrá el pavimento de una carretera. El objetivo de este estudio es analizar los pesajes realizados entre los años 2008 y 2017. A partir de lo anterior, se contabilizaron más de 12 millones de vehículos pesados, los cuales estaban distribuidos en la estación de pesaje de Limón y Cartago. Para cada vehículo se calculó el factor camión asociado y se determinó si el vehículo, según el peso de cada uno de sus ejes, incumplía lo establecido en el Decreto n.° 31363 del Ministerio de Obras Públicas y Transportes (MOPT, 2003). A partir de las variables factor camión y el incumplimiento se realizan modelos econométricos. Estos modelos toman el efecto de distintas variables de tipo de camión, espaciales y temporales, y el tipo de medición, sobre el factor camión y el incumplimiento. Los modelos econométricos consideran las siguientes variables: año, mes, tipo de vehículo, día, hora y el tipo de medición aplicado en las estaciones analizadas. Uno de los resultados más relevantes del presente estudio es que hubo un incremento en los factores camión y porcentajes de incumplimiento analizados al pasar de un sistema de pesaje manual a uno automatizado.

Abstract The truck factor is one of the main components in computing the load demand for highway pavements. The aim of this study is to analyse the databases on weighing’s carried out between 2008 and 2017. Therefore, more than 12 million heavy transport vehicles were counted, these vehicles were distributed in Limon and Cartago weighing stations. For each vehicle, the associated truck factor was calculated. Besides, according to the weight of each of its axles, it was determined if the vehicle did not comply with the provisions of the Legal Decree n.o 31363 of the MOPT. The econometric models are computed from the truck factor variables and non-compliance percentages. These models take the effect from different variables of the type of truck on the truck factor and non-compliance: spatial and temporal, and the type of measurement. The econometric models consider the following variables: year, month, type of vehicle, day, hour, and the type of measurement applied in the analysed stations. One of the results of this research is that there was an increase in the truck factors and non-compliance percentages analysed when going from a manual weighing system to an automated one.

Resumen La siguiente investigación tiene como objetivo determinar la serviciabilidad y capacidad resistente en el pavimento flexible del Azángaro-Salinas km 0+000 al km 3+000, en Puno, Perú. Los resultados determinan que, para el tramo indicado, se tiene un PSI (Índice de serviciabilidad de pavimento) de 3,41 de acuerdo con el método de Merlín, teniendo una clasificación de serviciabilidad buena. Así mismo, mediante los resultados de laboratorio, se establece la capacidad resistente en la subrasante, subbase y base. Con los CBR más críticos encontrados para cada una de las capas de la estructura del pavimento y con los espesores encontrados en campo, se logra realizar un diseño estructural obteniendo como resultado que sí se cumple con los requisitos del diseño. Las conclusiones son que la serviciabilidad es buena debido a que se determinó un IRI para cada tramo con un promedio de 2,15. Asimismo, se obtuvo un PSI promedio total de 3,41 correspondiendo una serviciabilidad buena de todo el tramo estudiado.

Abstract The following investigation aims to determine the serviceability and resistant capacity in a flexible pavement in Azángaro-Salinas km 0+000 to km 3+000, in Puno, Peru. From the results it was possible to determine that for the indicated section there is a PSI (Pavement Serviceability Index) of 3,41 according to the Merlin method, meaning that it has a good serviceability classification. Likewise, through the laboratory results, the resistant capacity is established for the subgrade, subbase, and base. After the most critical CBR was found for each of the layers of the pavement structure, and with the thicknesses found in the field, it is possible to carry out a structural design obtaining as a result that the design requirements were met. As conclusion, it was found a good serviceability of each section, since the determined IRI showed an average of 2,15. Likewise, the PSI total average of 3,41 corresponds to a good serviceability of the entire section studied.

Resumo A rápida urbanização das cidades tem gerado inúmeras consequências para os sistemas de drenagem de águas pluviais: aumento do escoamento superficial, piora da qualidade das águas subterrâneas e de sua escassez, causando inundações e afetando a saúde da população urbana. Uma alternativa para mitigar esses efeitos adversos é a inserção de práticas de low impact development, tais como pavimentos permeáveis, telhados verdes e células de biorretenção. Utilizando o modelo computacional Hydrus-1D, foi realizada uma simulação dos fluxos de água em meio poroso similar ao que ocorre em uma biorretenção, com dados de amostras de solo de uma área localizada em João Pessoa (PB). A infiltração do solo foi avaliada em ensaios de campo com o uso do infiltrômetro modificado Philip-Dunne. Parâmetros de desempenho hidrológico de um sistema de biorretenção foram investigados variando-se a altura de perfis de solo (100, 120, 130 e 150 cm), a profundidade de retenção na superfície (10, 20 e 30 cm) e a duração da chuva (20 e 60 min). Os resultados da simulação demonstraram que os melhores benefícios hidrológicos foram obtidos com chuvas de menor duração, com redução do pico de fluxo e do escoamento superficial de 100% para retenções de 20 e 30 cm.

Abstract The rapid urbanization of cities has generated numerous consequences for rainwater drainage systems: increased surface runoff, worsening quality, and scarcity of groundwater, causing floods and affecting the health of the urban population. An alternative to mitigate these adverse effects is the insertion of Low Impact Development (LID) practices such as permeable pavements, green roofs, and bioretention cells. Using the HYDRUS-1D computational model a simulation of water flows in a porous medium was performed, similar to what occurs in a bioretention, with data from soil samples from an area located in João Pessoa-PB. Soil infiltration was evaluated in field trials using a modified Philip-Dunne infiltrometer (MPD). Hydrological performance parameters of a bioretention system were investigated by varying height of soil profiles (100, 120, 130, and 150 cm), surface retention depth (10, 20, and 30 cm), and duration of rainfall (20 and 60 min). The simulation results showed that better hydrological benefits were obtained with shorter rainfall, with peak flow and surface runoff reduction by 100% for retentions of 20 and 30 cm.