Nondestructive techniques applied on experimental sections built with Recycled aggregates from CDW

La presente Tesis Doctoral estudia el uso de los Áridos reciclados (AR) de los residuos de construcción y demolición (RCD), de diferente naturaleza (hormigón y mixtos) en la formación de capas estructurales granulares no ligadas de capas granulares de pavimentos de carretera y vías ciclistas. Para ello se estudió la evolución de las prestaciones estructurales y funcionales de tres tramos experimentales reales donde se emplearon seis tipos de AR distintos. El primer estudio se realizó en la vía de servicio de la autovía A-376. Se emplearon dos tipos de AR: un suelo reciclado mixto (SRM), el cual fue obtenido del precribado a partir del rechazo de la fabricación de una zahorra reciclada mixta (ZRM). En la obtención de estos AR se emplearon RCD no seleccionados en origen mezclados con suelos de excavaciones. El SRM se empleó en la capa de formación de explanada, mientras que la ZRM se empleó como capa granular en el firme. Se construyó una sección de referencia con suelo seleccionado y zahorra artificial. Sobre toda la superficie del tramo experimental se extendió una capa de mezcla bituminosa de 5 cm de espesor. En una primera fase, todos los materiales fueron caracterizados, posteriormente en una segunda fase se controló su puesta en obra y una vez abierto al tráfico durante siete años se controló la evolución de las deflexiones y la regularidad superficial, siendo los resultados obtenidos en las secciones construidas con AR similares a las de los AN. En el segundo estudio se emplearon dos AR de RCD en la construcción de la vía ciclista que une el núcleo urbano de Córdoba con el Campus de Rabanales de la Universidad de Córdoba. Se empleó un suelo reciclado mixto en la explanada, obtenido del precribado en la fabricación de una ZRM en planta de tratamiento, esta zahorra se utilizó en la capa granular del firme. En la capa de rodadura se emplearon 4 cm de mezcla bituminosa en caliente. Todos los áridos empleados en el tramo experimental se caracterización mecánica, física y químicamente, posteriormente se controló su puesta en obra y una vez fue abierta al tráfico se estudió la evolución de la capacidad portante y módulos de elasticidad del firme durante tres años. Los resultados mostraron que la ZRM y el SRM pueden sustituir al suelo seleccionado y a la zahorra artificial en vías ciclistas y peatonales sin afectar a su funcionalidad. En el tercer estudio se emplearon dos AR obtenidos de la demolición de 105 viviendas próximas al aeropuerto de Córdoba con los que se construyeron un tramo experimental en la carretera CH-2, en concreto se empleó un AR mixto (ARM) en la formación de la explanada y un AR de hormigón (ARH) en la capa granular del firme. El ARH se obtuvo a partir de la trituración insitu con una machacadora móvil de mandíbulas de los RCD obtenidos de las cimentaciones y de las losas de hormigón de los pavimentos existentes, mientras que los ARM se obtuvieron a partir de las estructuras aéreas de las viviendas, muros y tejados. Como tramo de referencia se construyó una sección con zahorra artificial en la capa de firme. Se realizaron ensayos en laboratorio para caracterizar los tres materiales granulares empleados en el tramo experimental y una vez terminada la ejecución del tramo experimental de la carretera se puso en servicio, la evolución deflexiones y regularidad superficial se estudió durante 10 años, se midió el tráfico determinando que el número de vehículos diarios superaba los 9000, siendo su categoría de tráfico la T2 (200-799 vehículos pesados/día), los AR obtuvieron una mayor capacidad portante y mejor evolución con el paso del tiempo que la zahorra artificial empleada. Las características estructurales y funcionales de los firmes ejecutados con AR son similares a las de los firmes construidos con AN en carreteras de baja y media intensidad de tráfico, por tanto, los AR de RCD pueden sustituir a los AN en capas no ligadas de pavimentos sin que sus prestaciones mecánicas y funcionales se vean alteradas por el paso del tiempo. El empleo de los AR en detrimento de los AN reduciría la sobreexplotación de canteras y graveras, así mismo, se evita el depósito de RCD en vertedero o su vertido, con el consiguiente daño al medio ambiente, esta reutilización contribuye significativamente a la economía circular. Esta tesis incluye el cálculo de módulos a través de cálculos directos e inversos para los áridos reciclados, lo cual es un aspecto clave en el diseño de firmes.This Thesis studies the use of Recycled Aggregates (RA) obtained from Construction and demolition wastes (CDW) in unbound granular layers of roads and biking lanes. Six different types of RA were used in three different real scale experimental sections. The first study took place in the service road of the A-376 motorway, two different RA composed the granular layers, Mixed recycle soil (MRS) obtained from the screening wastes of a recycled mixed aggregate with excavation soil (RMAS), unselected CDW mixed with excavation soil was the raw materials of these RA, MRS formed the granular subbase and RMAS composed the granular base, there was a comparison section built with natural aggregates (NA) in its granular layers, 5 cm of hot mix asphalt (HMA) covered the surface of the Experimental Section. Chemical and physical properties were studied in laboratory, densities and moisture content were controlled during the construction of the road, deflections and surface regularity was measured for a period of seven years, results showed that RA and NA had a similar structural and service performance. The second study materialized in an Experimental Bike Lane (EBL) near the Rabanales Campus, two different RA obtained from CDW composed its granular layers, Recycled mixed aggregates with screening wastes (RMSW) formed the granular subbase, these RMSW were obtained from the wastes of the crushing of a recycled mixed aggregate (RMA) that constituted the granular base. A comparison section was built with NA in the base layer. Chemical and physical properties were studied in laboratory, during the construction of the experimental biking lane densities and moisture content were controlled, 4cm of HMA covered the Surface of the EBL, bearing capacity and elastic moduli of the layers were evaluated for a period of three years, results proved that RA can substituted NA in pedestrian and bike pavements. In the third study, two RA were obtained from the demolition of 105 dwellings near to the Cordoba Airport, these RA formed the granular layers of an Experimental section in the road CH-2, RMA composed the granular subbase and RCA constituted the granular base layer. A mobile jaw crusher made from the foundations and concrete of the existing rigid pavements the RCA, while structural parts of the houses, walls and roofs constituted the RMA. A comparison section was built with NA in the base layer. Chemical and physical properties were studied in laboratory, densities and moisture content were controlled during the construction of the road, deflections and Surface regularity was measured for a period of ten years. The number of daily vehicles was above 9000, this road would be classified as a T2 (200-799 heavy traffic vehicles per day and lane). RA obtained a higher bearing capacity than NA. Structural and functional characteristics of pavements built with RA are similar to those pavements constructed with NA, therefore RA from CDW can replace NA in unbound pavement layers. RA use in pavements can help to avoid landfilling with CDW and mitigate overexploitation of quarries and river gravels, this reuse of materials contributes significantly to the circular economy

Complete Real-Scale Application of Recycled Aggregates in a Port Loading Platform in Huelva, Spain

The application of recycled aggregates (RA) from construction and demolition waste and crushed concrete blocks is a very important challenge for the coming years from the environmental point of view, in order to reduce the exploitation of natural resources. In Spain, the use of these recycled materials in the construction of road bases and sub-bases is growing significantly. However, presently, there are few studies focused on the properties and behavior of RA in civil works such as road sections or seaport platforms. In this work, two types of RA were studied and used in a complete real-scale application. Firstly, recycled concrete aggregates (RCA) were applied in the granular base layer under bituminous superficial layers, and secondly mixed recycled aggregates (MRA) which contain a mix of ceramic, asphalt, and concrete particles were applied in the granular subbase layer, under the base layer made with RCA. Both RA were applied in a port loading platform in Huelva, applying a 100% recycling rate. This civil engineering work complied with the technical requirements of the current Spanish legislation required for the use of conventional aggregates. The environmental benefits of this work have been very relevant, and it should encourage the application of MRA and RCA in civil engineering works such as port platforms in a much more extended way. This is the first and documented real-scale application of RA to completely build the base and sub-base of a platform in the Huelva Port, Spain, replacing 100% of natural aggregates with recycled ones

De la impotencia al poder-no. Tópicos de la resistencia en la cultura iberoamericana

La pujante presencia de Iberoamérica en el ámbito geopolítico, así como en la literatura y las artes a nivel global, es indiscutible en nuestros días. A partir de ello, cobra vigencia analizar ciertos tópicos culturales de la demarcación. El marco teórico posestructuralista añade grandes posibilidades reflexivas al escrutinio investigativo. Gilles Deleuze y Félix Guattari, junto con Giorgio Agamben son los principales pensadores que introducen los ejes paradigmáticos de los estudios aquí reunidos, los cuales son producto de la colaboración internacional entre académicos de la Universidad Autónoma del Estado de México y la Universidad Pontificia Bolivariana de Medellín, Colombia, a través de la Red de investigación “Crítica a las manifestaciones del poder: violencia y resistencia”.Universidad Autónoma del Estado de Méxic

Nuevo repositorio multimedia de la Universidad de Murcia "tv.um.es"

El objetivo principal de este artículo es dar a conocer el nuevo repositorio multimedia de la Universidadde Murcia, el renovado portal Web�tv.um.es�, accesible desde . El portal está desarrollado haciendo uso de los estándares Web, así como de tecnologías muy distribuidas entre los usuarios. En el artículo se analizan los servicios disponibles desde el portal, y se destacan las novedades de esta versión. Entre ellas figuran el acceso autenticado de los usuarios para gestionar sus propios vídeos, y el nuevo buscador de objetos multimedia ordenados según la nomenclatura Internacional de la UNESCO1 para los campos de Ciencia y Tecnología. Esta iniciativa aporta nuevas herramientas en materia audiovisual, con el fin de dar respuesta a las necesidades del EEES2, especialmente para facilitar al profesorado su tarea docente, pero está abierta a toda la comunidad universitaria y a la sociedad en general

Recycling screening waste and recycled mixed aggregates from construction and demolition waste in paved bike lanes

This research conducts a full-scale study on the use of recycled mixed aggregates from construction and demolition waste and its screening waste in an experimental bike lane. The subgrade and the natural and recycled materials used as the base and subbase courses were characterized in a laboratory. During the construction of the experimental section, densities and deflections were measured to evaluate the mechanical behaviour of the structural layers and to determine the Young's modulus of the natural and recycled materials. After the lane was open to traffic for two years, the moduli evolution of the materials were studied. For the first time, the results obtained have shown the feasibility of using screening waste that does not meet the physical-mechanical and chemical requirements for use on paved roads as structural layers in bike lanes

Real-scale study of a heavy traffic road built with in situ recycled demolition waste

This real-scale study carries out a research of the behaviour of building demolition wastes in a road with high intensity traffic. A mobile recycling plant treated in situ the demolition wastes from 105 single-family homes. Recycled aggregates were made from two different sources: one aggregate came from concrete taken out of slabs and foundations (recycled concrete aggregate) and the second aggregate came from the remaining reinforced concrete structures, walls and roofs (recycled mixed aggregate). Both recycled materials and a crushed stone formed the granular base and subbase of the experimental paved section. A leaching test analysed the potential pollutant emissions of the recycled aggregates. Different tests were performed during construction of the experimental section, such as densities, loading plates and falling weight deflectometry. This research evaluated deflections and surface roughness for a period of seven years to study the behaviour of these recycled materials long term. The recycled aggregates used did not satisfy all the stipulations of the Spanish standards for granular material as road subbases/bases, such as size distribution, Los Angeles test limit, soluble salt and organic matter content in subbases. Despite this lack of compliance, the results of on-site tests over time compared the mixed recycled aggregate as subbase and the recycled concrete aggregate as the base with natural aggregates; the recycled aggregates presented a better structural behaviour and less surface deterioration than natural aggregates under a mean daily heavy vehicle flow of 371 vehicles per lane and an average daily traffic of 4469 vehicles per lane on average. The article includes the calculation of moduli through forward and back calculations for the recycled aggregates, which is a key aspect in pavement design The bearing capacity of recycled materials increased with time in the structural layer, which is unlike the trend in bearing capacity of the natural aggregates

Functional and structural parameters of a paved road section constructed with mixed recycled aggregates from non-selected construction and demolition waste with excavation soil

This paper evaluates the lab and in situ mechanical properties of non-selected mixed recycled aggregates from construction and demolition waste (CDW) used as base and subbase unbound materials. Excavation materials are mixed with CDW to produce recycled mixed aggregates with soil, as well as a finer material referred to as mixed recycled soil. The research was divided into two different stages: a laboratory study characterizing the properties of recycling aggregates and a road test track evaluating the long-term performance of these materials under real traffic and weather conditions. During construction, several density, plate load, and falling weight deflectometer tests were performed to determine the bearing capacity of all layers. A laser profiler was also used to obtained the international roughness index. After the road was opened to traffic, a follow up of deflections and surface roughness was performed during the following seven years. Two different moduli calculation methods were used: back calculation and forward calculation. Both methods shown acceptable values for these recycled materials. Low quality recycled mixed aggregates can be used as substitutes for natural aggregates as unbound layers. The mechanical performance and surface roughness values obtained from the experimental road shown an acceptable behaviour

Migraciones y movilidades en el centro de México

Migraciones y movilidades en el centro de México es un esfuerzo interinstitucional en el que los científicos participantes ponen en la mesa problemáticas fundamentales para tratar de entender algunos de los fenómenos más significativos en la materia, ubicados en siete entidades de la república: la Ciudad de México y los estados de Hidalgo, Morelos, México, Puebla, Querétaro y Tlaxcala. La región que conforman estas entidades constituyen uno de los puntos neurálgicos del desarrollo nacional.Centro de Investigación y Estudios en Movilidades y migraciones Internacionales Consejo Nacional de Población Sociedad Mexicana de Demografía Consejo Nacional de Ciencia y Tecnología Red Temática Trabajo y Condiciones Laborales de la UNA

First measurement of the ∣t∣|t|-dependence of incoherent J/ψ\psi photonuclear production

International audienceThe first measurement of the cross section for incoherent photonuclear production of J/$\psi$ vector meson as a function of the Mandelstam $|t|$ variable is presented. The measurement was carried out with the ALICE detector at midrapidity, $|y|<0.8$, using ultra-peripheral collisions of Pb nuclei at a centre-of-mass energy per nucleon pair $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV. This rapidity interval corresponds to a Bjorken-$x$ range $(0.3$$-$$1.4)\times 10^{-3}$. Cross sections are reported in five $|t|$ intervals in the range $0.04<|t|<1$~GeV$^2$ and compared to the predictions of different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a $|t|$-dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data

Charged-particle production as a function of the relative transverse activity classifier in pp, p−-Pb, and Pb−-Pb collisions at the LHC

International audienceMeasurements of charged-particle production in pp, p$-$Pb, and Pb$-$Pb collisions in the toward, away, and transverse regions with the ALICE detector are discussed. These regions are defined event-by-event relative to the azimuthal direction of the charged trigger particle, which is the reconstructed particle with the largest transverse momentum ($p_{\mathrm{T}}^{\rm trig}$) in the range $8<p_{\mathrm{T}}^{\rm trig}<15$ GeV$/c$. The toward and away regions contain the primary and recoil jets, respectively; both regions are accompanied by the underlying event (UE). In contrast, the transverse region perpendicular to the direction of the trigger particle is dominated by the so-called UE dynamics, and includes also contributions from initial- and final-state radiation. The relative transverse activity classifier, $R_{\mathrm{T}}=N_{\mathrm{ch}}^{\mathrm{T}}/\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$, is used to group events according to their UE activity, where $N_{\mathrm{ch}}^{\mathrm{T}}$ is the charged-particle multiplicity per event in the transverse region and $\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$ is the mean value over the whole analysed sample. The energy dependence of the $R_{\mathrm{T}}$ distributions in pp collisions at $\sqrt{s}=2.76$, 5.02, 7, and 13 TeV is reported, exploring the Koba-Nielsen-Olesen (KNO) scaling properties of the multiplicity distributions. The first measurements of charged-particle $p_{\rm T}$ spectra as a function of $R_{\mathrm{T}}$ in the three azimuthal regions in pp, p$-$Pb, and Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV are also reported. Data are compared with predictions obtained from the event generators PYTHIA 8 and EPOS LHC. This set of measurements is expected to contribute to the understanding of the origin of collective-like effects in small collision systems (pp and p$-$Pb)