Browsing by Author "Araya Letelier, Gerardo Andrés"

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    A detailed experimental mechanical characterization of multi-perforated clay brick masonry
    (2023) Calderón Díaz, Sebastián Andrés; Sandoval Mandujano, Cristián; Araya Letelier, Gerardo Andrés; Aguilar, Víctor
    Multi-Perforated Clay Bricks (MPCLBs) are widely used in the construction of modern masonry structures worldwide, including earthquake-prone areas. However, few experimental studies have been carried out aimed at performing a detailed mechanical characterization of their behavior under different loading conditions. In the present paper, tests on masonry constituent materials and assemblages (triplets, rectangular prisms, and panels) made of MPCLBs are carried out, and some relationships between masonry properties useful for design purposes or numerical simulations are derived, including compression strength, Young's modulus, shear strength, and shear modulus. From the results, it is observed that decreasing mortar compressive strength and increasing joints' height are detrimental to masonry properties. Furthermore, a masonry compressive strength equation is fitted to the test results representative of Chilean masonry construction, which significantly overperforms the current Chilean standard formula. Also, digital image correlation is used to confirm the effect of mortar entering bricks' perforations on the shear response of the mortar-brick interface.
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    Animal fibers as water reservoirs for internal curing of mortars and their limits caused by fiber clustering
    (2021) Antico, F. C.; Rojas, P.; Briones, F.; Araya Letelier, Gerardo Andrés
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    Behavior of Partially Grouted Concrete Masonry Walls under Quasi-Static Cyclic Lateral Loading
    (2020) Calderón Díaz, Sebastián Andrés; Vargas, Laura; Sandoval Mandujano, Cristián; Araya Letelier, Gerardo Andrés
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    Biopolymer-Waste Fiber Reinforcement for Earthen Materials: Capillary, Mechanical, Impact, and Abrasion Performance
    (2020) González Calderón, H.; Araya Letelier, Gerardo Andrés; Kunze, S.; Burbano García, C.; Reidel, R.; Sandoval Mandujano, Cristián; Astroza, R.; Bas Mir, Fernando
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    Caracterización y mejoramiento del comportamiento sísmico de tabiquería de estructura metálica con planchas de yeso-cartón
    (2021) Fuente Navarro, Christopher de la; Araya Letelier, Gerardo Andrés; Pontificia Universidad Católica de Chile. Escuela de Construcción Civil
    Los tabiques no estructurales confeccionados con paneles de yeso-cartón con montante metálico doblado en frío (tabiques en adelante, por brevedad) son elementos altamente utilizados en las edificaciones y se caracterizan por su alta vulnerabilidad sísmica. A modo de ejemplo, estudios recientes han mostrado que los tabiques pueden representar un 27% de las pérdidas económicas de los elementos no-estructurales ante un terremoto y el terremoto Mw 8.8 del 27 de febrero de 2010 en Chile generó pérdidas que alcanzaron los 33 billones de dólares siendo un gran porcentaje de estas debido a daño de tabiques. Pese a lo anterior, el diseño y construcción de tabiques se sigue realizando de manera tradicional y, por lo tanto, estos elementos continúan siendo muy susceptibles a dañarse incluso ante pequeñas deformaciones laterales generadas por sismos de baja y mediana intensidad. Estos sismos de baja y mediana intensidad, que generalmente no dañan los sistemas estructurales, se presentan con alta frecuencia en la vida útil de los edificios en lugares sísmicos como Chile y, por lo tanto, pueden dañar estos tabiques de manera frecuente lo que explica su alto impacto en términos de pérdidas económicas en ciclo de vida debido a daño sísmico.Debido a lo anterior, la caracterización probabilística del comportamiento sísmico de los tabiques, en relación a sus daños consecutivos debido a la imposición de deformaciones laterales normalizadas por la altura inicial (story drift ratio (SDR), en inglés, o simplemente drift), junto a proposición de nuevas estrategias para mejorar estos desempeños sísmicos son aún materia de interés. En consecuencia, el presente documento aborda estos dos temas.En primer lugar, este estudio consolida 14 investigaciones experimentales referidas a la evaluación de los daños progresivos generados en los tabiques debido a la imposición de niveles crecientes de SDR. Se establecen 3 estados de daño (DS, por su abreviación del inglés damage state) consecutivos y relativos a los mecanismos de reparación asociados al daño de los tabiques: DS1 (fisuras superficiales que pueden ser reparadas mediante empaste y pintura) , DS2 (grietas y trituración de la plancha que pueden ser reparadas mediante reemplazo de la plancha) y DS3 (daño total del tabique, incluyendo la estructura montante del tabique, la cual debe ser reparada mediante la demolición del tabique dañado y la construcción de un nuevo tabique). Los resultados de esta investigación encontraron medianas para DS1, DS2 y DS3 equivalentes 0.31%, 0.81% y con 1.5%, respectivamente, lo que confirma la muy baja resistencia de estos tabiques ante deformaciones laterales impuestas por sismos.En segundo lugar, este estudio aborda el mejoramiento de los tabiques, el cual tiene algunas alternativas, incluyendo opciones como: (1) aislar los tabiques de las deformaciones laterales; y (2) el mejoramiento de los componentes constitutivos de los tabiques de manera de hacerlos más resistentes a las deformaciones laterales, lo cual se puede explorar (entre otras estrategias) mediante la adición de fibras a las planchas de yeso-cartón, siendo esta la opción seleccionada en este estudio para una revisión bibliográfica. Este estudio consolida 8 investigaciones que adicionaron fibras a paneles de yeso-cartón, concluyendo que el uso de fibra de vidrio, fibra de madera y tableros de yeso-cartón más densos se obtienen resultados favorables, aumentando los drift asociados a DS1, DS2 y DS3 en comparación a los tabiques con planchas de yeso-cartón tradicional. Finalmente, se propone un plan experimental, para evaluar la incorporación de fibras comerciales de polipropileno, complementarias a las evaluadas en los estudios previos, cuya ejecución se propone como trabajo futuro.
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    Collapse assessment of a chilean code-conforming reinforced concrete office building
    (Earthquake Engineering Research Institute, 2018) Araya Letelier, Gerardo Andrés; Parra Torres, Pablo Fernando; López-García, Daniela; García Valdés, Óscar Andrés; Candia, G.; Lagos, R.
    Chilean buildings are periodically subjected to earthquakes and their satisfactory performance preventing collapse is widely known. Yet, as a result of the Mw 8.8 2010 Chile earthquake, one reinforced concrete building collapsed and many others were severely damaged, raising concerns about the collapse margin of these structures. Modifications to the Chilean codes were introduced after this earthquake, but Chilean codes are still prescriptive and assessments of the collapse risk of current Chilean buildings is limited. This study evaluates the collapse potential of a code-conforming reinforced concrete office building in Santiago, Chile, whose structural system has a core of two cantilever C-shaped walls surrounded by intermediate moment frames. The architectural layout was designed based on a statistical analysis of the building inventory in Santiago. Incremental dynamic analyses using 45 Chilean earthquakes were performed over a nonlinear model of the building to estimate its collapse fragility, which was combined with a site specific seismic hazard analysis to estimate the mean annual frequency of collapse (γc), and the probability of collapse in 50 years (Pc(50)). Results of γc and Pc(50) were 1.2x10-4 and 0.6%, respectively, and deaggregation of γc is dominated by small to medium earthquake intensities.
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    Collapse risk assessment of a Chilean dual wall-frame reinforced concrete office building.
    (2019) Araya Letelier, Gerardo Andrés; López-García González, Diego; García, Andrés; Parra, Pablo Fernando; Candía, G.; Lagos, René
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    Design of partially grouted reinforced masonry shear walls in an earthquake-prone area: Proposal based on the LRFD approach
    (2025) Vargas Carvajal, Laura Andrea; Aguilar,Víctor; Calderón, Sebastián; Araya Letelier, Gerardo Andrés; Sandoval Mandujano, Cristián
    There is a lack of reliability assessment of modern structural masonry design. Hence, a novel reliability-based calibration of the in-plane shear ultimate limit state for partially grouted reinforced masonry shear walls (PGRMSWs) is presented. This calibration allows for the proposal of a load and resistance factor design (LRFD) methodology oriented to in-plane shear design, responding to the need to update the reinforced masonry Chilean code, which is currently based on the allowable stress design (ASD) format. An extensive database of material and assembly tests and numerical research that made this code update proposal feasible are summarized. The reliability-based calibration was performed aiming to define a target reliability index (βT) and the corresponding strength reduction factors (φ) were recommended. A value of βT = 2.5 is defined based on the reliability analysis of representative existing structures against earthquake-induced shear force. The results allow for recommending φ = 0.60 for walls made of multi-perforated clay bricks and φ = 0.70 for walls made of hollow concrete blocks. Additionally, φ = 0.85 and φ = 0.65 are recommended for flexural and axial strength of compression-controlled walls by adapting international standards to Chilean practice. Comparisons of the required horizontal reinforcement between ASD and LRFD methodologies are presented for a 4-story case study building. The results show that the total reinforcement quantities from ASD and LRFD methodologies are similar, which means the proposal does not imply a more restrictive and expensive design; yet, the LRFD proposal provides designs with a uniform reliability level across various load scenarios.
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    Development and Testing of a Friction/Sliding Connection to Improve the Seismic Performance of Gypsum Partition Walls
    (2019) Araya Letelier, Gerardo Andrés; Miranda, Eduardo; Deierlein, Gregory G.
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    Development of seismic fragility functions of partially grouted reinforced masonry shear walls
    (2019) Sanhueza, Matías.; Araya Letelier, Gerardo Andrés; Calderón Díaz, Sebastián Andrés; Sandoval Mandujano, Cristián; Murcia Delso, Juan.
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    Effectiveness of polypropylene fibers on impact and shrinkage cracking behavior of adobe mixes
    (2019) Araya Letelier, Gerardo Andrés; Antico, Federico Carlos; Concha Riedel, José; Glade, Andres; Wiener, María J.
    Earth has been used as construction material for thousands of years and still at present earthen shelters are widely inhabited due to their comfort and low environmental impacts. Despite their advantages, earthen materials are brittle and their performance can be enhanced with the addition of fibers. This study addresses the use of different dosages of micro-polypropylene fibers in adobe mixes. The results show that adobe mechanical damage performance is sensitive to the dosage of polypropylene fibers increasing impact strength and reducing drying shrinkage cracking.
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    Enhancing seismic performance of reinforced concrete dual wall-frame buildings: Integrating alternative modeling and design approaches
    (HUMANA PRESS INC, 2025) López Machado, Nelson Andrés; López-Garcia González, Diego; Parra, P. F.; Araya Letelier, Gerardo Andrés
    This study delves into two critical issues related to the seismic analysis and design of Chilean reinforced concrete dual wall-frame buildings. First, it evaluates the efficacy of Special Boundary Elements (SBEs) in shear walls, whose seismic performance enhancement remains uncertain despite recent (i.e., after the 2010 earthquake) mandates in Chile. Second, it investigates the relevance of explicit inclusion of slabs in 3D nonlinear models (in dual wall-frame buildings slabs are often not modeled for computational expediency). Various analytical models of a representative 16-story dual wall-frame archetype building are meticulously evaluated using Perform3D. Different vertical heights of the SBEs (ranging from 0 to 5 stories) and different values of the effective flexural stiffness of the slabs (ranging from 0 to 100% of the gross cross-section stiffness) are considered. Subduction ground motions representative of the Chilean seismicity are selected and scaled based on detailed seismic hazard analyses. Evaluation metrics include collapse fragility functions and 50-year collapse probabilities. Inelastic deformations in the shear walls are thoroughly analyzed. It was found that the effective flexural stiffness of the slabs has a non-negligible influence on the analytical collapse probability, and that SBEs do not provide ductility but they do reduce the collapse probability.
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    Enhancing seismic performance of reinforced concrete dual wall-frame buildings: Integrating alternative modeling and design approaches
    (2025) López Machado, Nelson Andrés; López-Garcia González, Diego; Parra, P. F.; Araya Letelier, Gerardo Andrés
    This study delves into two critical issues related to the seismic analysis and design of Chilean reinforced concrete dual wall-frame buildings. First, it evaluates the efficacy of Special Boundary Elements (SBEs) in shear walls, whose seismic performance enhancement remains uncertain despite recent (i.e., after the 2010 earthquake) mandates in Chile. Second, it investigates the relevance of explicit inclusion of slabs in 3D nonlinear models (in dual wall-frame buildings slabs are often not modeled for computational expediency). Various analytical models of a representative 16-story dual wall-frame archetype building are meticulously evaluated using Perform3D. Different vertical heights of the SBEs (ranging from 0 to 5 stories) and different values of the effective flexural stiffness of the slabs (ranging from 0 to 100% of the gross cross-section stiffness) are considered. Subduction ground motions representative of the Chilean seismicity are selected and scaled based on detailed seismic hazard analyses. Evaluation metrics include collapse fragility functions and 50-year collapse probabilities. Inelastic deformations in the shear walls are thoroughly analyzed. It was found that the effective flexural stiffness of the slabs has a non-negligible influence on the analytical collapse probability, and that SBEs do not provide ductility but they do reduce the collapse probability.
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    Escoria de cobre: una alternativa sustentable para la construcción de pavimentos rígidos
    (Departamento de Ingeniería Civil de la Universidad Católica de la Santísima Concepción, Chile., 2025) Valdes Kern, Benjamin Eduardo; Burbano Garcia, Claudia Patricia; Silva, Yimmy; Araya Letelier, Gerardo Andrés; González Hormazabal, Marcelo Andrés
    Este artículo investiga el uso de escoria de cobre (EC), residuo masivo de la industria minera, como material cementicio suplementario (MCS) en mezclas de hormigón con posibles usos en pavimentos, evaluando las propiedades mecánicas y durabilidad frente a agentes agresivos. Experimentalmente, se observó que reemplazar hasta un 20% (volumen) del cemento con EC no reduce significativamente la resistencia a la flexo-tracción (FT), y que un 10% de EC aumenta en un 3,3% la resistencia a la FT a largo plazo (360 días) respecto al hormigón de referencia (sin EC). Además, se registró una reducción de la profundidad de penetración de agua en un 36% y 38%, a los 28 y 90 días respectivamente. Se concluye que la EC tiene un uso potencial para mezclas de hormigón para pavimentos, con un adecuado desempeño estructural y un menor impacto medioambiental, aunque son necesarios estudios adicionales específicos de pavimentación para validar estos hallazgos
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    Evaluación de la probabilidad de colapso de un edificio de oficinas chileno de hormigón armado debido a actividad sísmica
    (2019) Araya Letelier, Gerardo Andrés; López-García González, Diego; García, Andrés; Parra, Pablo Fernando
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    Experimental mechanical-damage assessment of earthen mixes reinforced with micro polypropylene fibers
    (2019) Araya Letelier, Gerardo Andrés; Concha-Riedel, J.; Antico, F. C.; Sandoval Mandujano, Cristián
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    Fragility functions for partially-grouted masonry shear walls with bed-joint reinforcement
    (2019) Araya Letelier, Gerardo Andrés; Calderón Díaz, Sebastián Andrés; Sandoval Mandujano, Cristián; Sanhueza, Matías; Murcia Delso, Juan
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    Hydration kinetics and mechanical performance of cement pastes with copper slag as supplementary cementitious material
    (2025) Burbano García, Claudia Patricia; Silva Urrego, Yimmy Fernando; Araya Letelier, Gerardo Andrés; González Hormazabal, Marcelo Andrés
    The growing global demand for concrete infrastructure and cement highlights the need to mitigate the environmental impact of cement production. Incorporating alternative supplementary cementitious materials (SCMs) has emerged as a promising strategy. This research investigates the effect of copper slag (CS), a significant global mining-sector waste, as SCM in cement pastes, focusing on hydration and mechanical performance in both the short and long term. CS was used as SCM at dosages of 0 %, 10 %, 20 %, 30 %, and 50 % by volume. The hydration evolution of cement paste mixtures was evaluated using isothermal calorimetry, compressive strength tests, X-ray diffraction (XRD), differential thermogravimetry (DTG), and field emission scanning electron microscopy. Results indicate that up to 20 % CS replacement did not negatively affect compressive strength in the long term, while dosages above 20 % led to a monotonic reduction. XRD and DTG analyses validated the pozzolanic effect of CS, evidenced by the formation of new Fe-siliceous hydrogarnet phases and a reduction in CH content at later ages. Additionally, a predictive model combining random forest and polynomial regression techniques was developed to accurately forecast compressive strength as a function of CS dosage and curing time. This study concludes that incorporating up to 20 % CS as SCM can reduce CO2 emissions associated with the clinker factor without significantly compromising long-term mechanical performance, and offers a viable alternative for greener cement production.
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    In-plane shear strength and damage fragility functions for partially-grouted reinforced masonry walls with bond-beam reinforcement
    (2021) Zhang, Zhiming; Murcia-Delso, Juan; Sandoval Mandujano, Cristián; Araya Letelier, Gerardo Andrés; Wang, Fenglai
    This paper presents a study on the in-plane shear response of partially-grouted reinforced masonry walls with bond-beam reinforcement. A database of 95 tests on partially-grouted walls made of concrete hollow blocks was compiled from experimental studies reported in the literature to characterize the capacity and damageability of walls subjected to in-plane lateral loading. The database has been used to evaluate the accuracy of existing design shear strength equations for partially-grouted walls. It is concluded that the shear strength expressions in the Masonry Standards Joint Committee (MSJC) code and Canadian standard are unconservative for partially-grouted walls. A modified equation based on the MSJC expression is proposed which better estimates the shear strength of this type of walls. Seismic fragility functions are also derived based on the experimental database to calculate the probability of experiencing moderate and severe damage in a partially-grouted wall for a given story-drift ratio deformation or normalized shear force demand. The resulting fragility functions show that the normalized shear demand is better correlated with the level of damage than the story-drift ratio.
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    Influence of different design parameters on the seismic performance of partially grouted masonry shear walls
    (2021) Calderón Díaz, Sebastián Andrés; Sandoval Mandujano, Cristián; Araya Letelier, Gerardo Andrés; Inzunza, Ernesto; Arnau, Oriol
    In recent earthquakes in Chile (e.g., Maule’s 2010 earthquake), buildings built with bed-joint partially grouted reinforced masonry (BJ-PG-RM) shear walls made of multi-perforated clay bricks (MPCB) have not collapsed, although significant damages have been reported. Additionally, experimental data on the influence of the different design parameters that control its seismic behavior is scarce, and the available expressions for estimating their lateral resistance are inaccurate. To address these issues, nine full-scale BJ-PG-RM walls made of MPCB were tested under axial pre-compression and cyclic lateral loads. The study addressed the influence of the aspect (height-to-length) ratio, axial pre-compression, mortar compressive strength, mortar joints’ thickness, bricks’ height, and horizontal and vertical reinforcement ratio. The results were analyzed in terms of hysteretic response, damage evolution, seismic performance parameters (shear strength, equivalent viscous damping ratio, ductility, and lateral stiffness degradation). All designed walls failed in a diagonal tension failure mode. Besides, all studied variables influenced the stresses and crack patterns. Also, the shear strength increases when: (i) lower aspect ratio or joint thickness are used; and (ii) higher axial load ratio, horizontal reinforcement ratio, vertical reinforcement ratio, or mortar compressive strength are used. Moreover, when damage progresses, the lateral secant stiffness decays faster as a result of: (i) larger joint thickness or vertical reinforcement ratio; (ii) lower mortar compressive strength. Most walls exhibited an equivalent viscous damping ratio between 5% and 10% for an intermediate state of damage. However, the evaluated design parameters did not considerably affect the development of the viscous damping ratio as a function of the drift ratio. The displacement ductility of the walls ranged from 1.5 to 2.5, where the height of bricks and the vertical reinforcement ratio had positive effects, and the joint thickness, the mortar compressive strength, and the horizontal reinforcement ratio a negative effect. The lateral resistance of tested walls was also estimated with six expressions, but none of them provided accurate results.