The fracture resistance of a chemically stabilized base or subbase layer is important to the durability and sustainability of a pavement structure. Thus, an appropriate test protocol to characterize the fracture resistance of stabilized bases, subbases, and subgrade soils is essential to the design of pavement materials and structures. This paper proposes a protocol developed on the basis of the semicircular bending test to measure fracture resistance (i.e., fracture energy and fracture toughness) of chemically stabilized material. The effects of three test variables, including specimen thickness, notch length, and loading rate, on fracture properties were investigated, and appropriate values for these test variables were selected for the semicircular bending test protocol. The proposed semicircular bending test method was successful in characterizing the fracture resistance of three chemically stabilized materials. To address fracture properties of the chemically stabilized material more definitively, three-dimensional zone modeling was used and the simulations agreed very well with the experimental results. Both the fracture properties obtained from the experiment and the cohesive zone modeling indicated that polymer-stabilized limestone exhibited a much higher fracture resistance than cement-stabilized limestone and cement-stabilized sand. However, the polymer used demonstrated susceptibility to degradation in the presence of water. Correction of this limitation is the focus of ongoing research on this type of polymer.

Hydrated lime is widely used as a mineral filler to improve several properties of bituminous materials such as reducing the susceptibility of the composite to moisture-induced damage. Although experimental evidence supports the efficacy of using hydrated lime as a mineral filler, the molecular scale mechanism of reactivity of hydrated lime within the bitumen to reduce moisture damage is not understood. This is important when considering the durability of structural applications of bituminous materials such as asphalt concrete pavements subjected to both environmental and loading extremes. In this study, the interaction between hydrated lime and the key molecular building blocks of bitumen is modeled using density functional theory and compared against analogues of other common fillers such as calcite and quartz. Free energies of dissociation (ΔG dissoc) are calculated, and the nature of the bonds is characterized with contour maps of the Laplacian of the electron density. Hydrated lime is capable of reacting with specific functional groups in bitumen moieties and developing strong, water-resistant complexes. Among the functional groups investigated, carboxylic acids are the preferential reaction sites between hydrated lime and the bitumen moieties. Values as high as ΔG dissoc = +49.42 kcal/mol are reported for hydrated lime with water as the surrounding solvent. In contrast, analogues of calcite (ΔG dissoc = +15.84 kcal/mol) and quartz (ΔG dissoc = +4.76 kcal/mol) are unable to chemically react as strongly as hydrated lime in the presence of water. Contour maps of the Laplacian of the electron density indicate that the bonds between hydrated lime and model asphalt moieties are of an ionic nature. The atomistic modeling results correlate with thermodynamic calculations derived from experimental constants and are consistent with infrared spectrometric data.

Agregar un nuevo canal de ventas genera nuevos desafíos en términos de gestión de inventarios debido a la diferencia de tamaño de los pedidos y tiempos de cumplimiento además de la incertidumbre en la demanda de ambos canales. El objetivo es diseñar un modelo de gestión de inventarios mixto compuesto por un modelo de reaprovisionamiento conjunto para el canal tradicional de tiendas minoristas y un modelo de revisión continua con para el canal Online, ambos con demanda estocástica, por la diferencia que presentan en su gestión operativa. Se desarrollo un método heurístico para la solución del problema y para su validación se evaluaron ejemplos numéricos donde se encontró una reducción de 11% en el costo de la política de inventario del almacén de doble canal con el modelo propuesto el cual busca representar una aproximación de la gestión como lo es el reaprovisionamiento conjunto en los minoristas.

In 2012, a geophysical survey was conducted inside the open space of a Hispanic Dominican convent in Panama (Central America); its ruins form part of the Panamá Viejo Historical Monument Complex, which was declared a UNESCO World Heritage site in 2003. he geophysical survey consisted of measuring the apparent electrical resistivity values along 24 parallel proiles inside the convent; the aim of this approach was focused on generating 3D electrical resistivity tomography in order to detect buried structures that could be associated with a possible cloister in this area of the convent. his dataset was inverted using a smooth inversion algorithm and shows important electrical anomalies on three horizontal maps at depths of 0.29, 0.90 and 1.60 m. he main electrical anomalies presented linear and isolated geometries that, in accordance with the archaeological excavations conducted at the site, are linked to a series of buried cultural features associated with the convent's cloister, such as perimeter walls, pillar footings and bases made of stone as supports for the gallery of a second loor. his study was also able to identify other archaeological features that could be linked to the initial stages of the construction of this important building. Résumé : En 2012, une prospection géophysique a été faite sur l'espace libre d'un couvent hispanique dominicain au Panama (Amérique centrale). Ses ruines font partie du Complexe Monumental Historique de Panamá Viejo qui a été classé au Patrimoine Mondial de l'Unesco en 2003. L'étude géophysique a consisté à mesurer les valeurs de la résistivité électrique apparente le long de 24 proils parallèles à l'intérieur du couvent. Cette approche par tomographie de résistivité électrique 3D avait pour but de détecter les structures enterrées qui pourraient être associées à un cloître dans cette partie du couvent. Les données ont été inversées à l'aide d'un algorithme d'inversion lisse. Les variations de la résistivité sont importantes, elles sont présentées pour 3 sections horizontales aux profondeurs de 0,29, 0,90 et 1,60 m. Les principales structures présentent des périphériques linéaires bien identiiables qui, conformément aux fouilles archéologiques menées sur le site, peuvent être associées au cloître du couvent : murs périfériques, pieds et bases en pierre supports de la galerie d'un deuxième étage. Cette étude a également permis d'identiier d'autres caractéristiques archéologiques qui pourraient être liées aux états antérieurs de la construction de cet important bâtiment.