Recent Submissions

  • Sustainable Concrete with Coconut Fibers to Improve its Mechanical Characteristics in Buildings

    Anderson, Mas Mendez Jhonn; Smith, Solano Roman Ruthenford; Carmen, Carrera Cabrera Elsa (Trans Tech Publications Ltd, 2022-01-01)
    In the search for a dosage that allows us to design a sustainable concrete with greater resistant capacity. Different solutions are proposed that allow us to find the right addition to achieve a better performance in the physical and mechanical characteristics of concrete in fresh and hardened state. For the development of the research, the influence of the addition of coconut fiber in concrete is evaluated. For this reason, various mix designs were developed: The pattern and with the addition of coconut fiber in partial replacement of fine aggregate with designs of 0.50 %, 1.00%, 1.50% and 2.00%, making a total of 90 concrete specimens which are represented in cylindrical and rectangular specimens. For each mixture, tests were carried out for its fresh state and hardened state. From the analysis it is concluded that the most optimal relationship is achieved with 1.00% coconut fiber addition, achieving compressive and flexural strengths at 28 days of 231.60 kg / cm2 and 83.10 kg / cm2, representing percentages of increase in 11.00% and 9.00% respectively.
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  • Mechanical Behavior of Low Plasticity Clay Soil Stabilized with Rice Husk Ash

    Jayo, B.; Duran, G. (Trans Tech Publications Ltd, 2022-01-01)
    There is much research on how the addition of rice husk ash (RHA) and lime improves the mechanical behavior of the soil, particularly in clayey soils. RHA is a waste material and polluting for the environment; Therefore, its use can be considered as an economic and ecological alternative. The main objective of this analysis is to determine the influence of rice husk ash (RHA) to stabilize this type of soil. This research is based on the development of an alternative method for the improvement of low plasticity clay soils using an agricultural residue such as rice husk ash and lime for use in civil works. Soil mixtures with rice husk ash were made in different percentages to evaluate its geotechnical behavior as a stabilizer. Laboratory tests like OMC, MDD tend to increase when RHA is added. Shear strength increased as ash was added, where it reached a higher value with the addition of 40% RHA, increasing from 197.70 kPa to 323.00 kPa. Finally, the results obtained show an improvement due to the presence of RHA, however, the investigation is still in process to determine if the addition of higher RHA continues to improve or decrease its shear stress.
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  • Settlement Comparison Research in Response to Gravel Columns with Concrete under a Distributed Vertical Dynamic Load

    Cardenas, V.; Agreda, N.; Vásquez, J. (Trans Tech Publications Ltd, 2022-01-01)
    Currently there are different techniques of soil improvement. One of them is the gravel columns that is one of the most popular and profitable techniques for soil improvement. This method of breeding increases the physical and mechanical properties of the soils. However, it has limitations, because part of the aggregates in non-specific areas can generate settlement that affects the structure. In this study, it reduces the settlement of the gravel column by making a change in a certain percentage in its structure by a concrete that is not reinforced. Different heights of the concrete are visualized, in addition to having different variants such as columns that are next to the base, as well as the columns that are on the sandy ground. The research was carried out with the simple compression machine with the concept of unit cell. The yield of the hybrid columns (gravel and concrete) had a better yield which was 20% compared to the traditional gravel columns.
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  • Influence of the P-delta Effect and Stiffness Irregularity on the Structural Behavior of Reinforced Concrete Buildings

    Zavala, D. J.; Torres, C. J.; Moreno, J. D. (Institute of Physics, 2022-01-01)
    In this research, the influence of the stiffness irregularity and the p-delta effect on the structural behavior of a reinforced concrete building is analyzed. The main objective is to determine the impact of the stiffness irregularity and the p-delta effect on the structural behavior in regular and irregular buildings. First, the linear dynamic analysis procedure is performed in order to determine the structural response in terms of drifts, shear force and moments per floor. Subsequently, we proceed with the nonlinear static analysis procedure to obtain the capacity curve of the structure. The post elastic stiffness and the overall ductility of the structure are determined from the capacity curve. Finally, a comparative analysis of the responses from the linear and nonlinear analysis is carried out to determine the percentage variation of the results. When analyzing the structures that consider the stiffness irregularity and the p-delta effect, variations of up to 16.50%, 11.00% and 14.00% have been obtained in drifts, shear force and moments per floor respectively, which are considerable values. When the p-delta effect is considered in structures with the presence of stiffness irregularity, there is a variation in stiffness of up to 59.85%. With this result it is explained that the p-delta effect produces a greater degradation of the overall stiffness of the structure.
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  • All Conditions for Synchronous Harmonic Natural Oscillations in LC Circuits

    Morales, Cesar A. (Institute of Electrical and Electronics Engineers Inc., 2022-01-01)
    The full set of conditions for synchronous harmonic oscillations in multiple LC circuits are established. These are for discrete lossless linear systems in source-free response. An Electric Networks literature review indicates that even the very basic condition for synchronous harmonic free oscillations is rarely presented, which is: initial conditions as an eingenvector for the initial charges and no currents (for t = 0). It is demonstrated herein that there are more conditions: three in total; in addition, simulation results are presented to illustrate all these possibilities, in which synchronous harmonic oscillation can actually be experienced. It is also noted here, that reactance or LC networks are correct models in Physics (pulsed power systems, metamaterials and metal-dielectric composites) and for Engineering devices (electrotherapy, ignition and radio). IEEE
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  • Modelling of a Stilling Basins with Sloping Apron in IBER to Improve Efficiency in High-slope Rivers

    Zabaleta, Y.; Espejo, O. K.; Fernández, J. M.; Santos, S. (Institute of Physics, 2022-01-01)
    This research shows the influence of stilling basin slopes on energy loss in rivers with a high gradient. This study takes as a case San Pedro water intake (Ayacucho, Peru). The main objective is to improve efficiency of stilling basins in rivers with high slope. Five dissipation pools of different slopes were modelled: 0%, 1.52%, 3.04%, 4.56% and 6.08% to propose the optimum pool among these, for the San Pedro intake. Results were validated by means of a Sensitivity Analysis, trough comparison with the results of previous investigation and results of modelling San Pedro river with HEC-RAS and IBER. It was obtained that the steeper the slope of the stilling basin, the higher the specific energy loss, the higher the output rate, the longer the stilling basin. It can be concluded that the 3.04% slope stilling basin is the most appropriate for the 6.08% slope river since the slope variation is not abrupt as in the case of the horizontal one, that is, 30% more energy loss with respect to the horizontal pool and velocity and Froude results similar to the modelling of the San Pedro river.
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  • Compressed earth blocks for rural housing in seismic zones using bagasse fibers from sugarcane

    Tello, Jose; Cabrera, Marlo; Rodríguez, Jose; Eyzaguirre, Carlos (Trans Tech Publications Ltd, 2022-01-01)
    The low resistance to compression and flexural of conventional earth techniques such as adobe in the occurrence of earthquakes causes the immediate collapse or failure of structures built with this material. These deficiencies are caused by the lack of stabilization and reinforcement processes of the block, which causes low mechanical performance in the face of seismic forces. The most common structures to collapse during earthquakes in developing countries such as Peru are the self-built adobe rural houses, being the most used in these areas due to the high housing deficit and the high demand for low-cost housing. One solution to this problem is the use of reinforced CEB in rural housing. In the present investigation some properties such as absorption, compressive strength and flexural strength are studied, the results indicate that the compressive strength and flexural strength increase when compared with an unstabilized earth block, however, the increase in absorption is proportional to the amount of fiber so it was used in small proportions less than 1% in the mixture.
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  • Consumer protection in Peru: origins, evolution, and main regulatory influences

    Carranza Álvarez, C.; Francia, O. A.Alcántara (Springer, 2022-03-01)
    In the following text, the authors address the origins and evolution of consumer protection in Peru, as well as highlighting the main regulatory influences of the current 2010 Consumer Protection and Defence Code with regard to consumer sales (defective products), and the regime of abusive clauses, to which is added a reference to protection of personal data.
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  • Concrete sustainable buildings using domestic wastewater treated

    Verde, Sharlys; Aranibar, Aderly; Rodriguez, Jose; Eyzaguirre, Carlos (Trans Tech Publications Ltd, 2022-01-01)
    During recent years, the rapid growth of the population in urban areas has promoted the development of housing, roads, shopping centres and industries; having increased the consumption of tap water in the concrete industry. A solution to this problem, is to use domestic wastewater treated, due to the large quantities produced and the need to include them within the life cycle of the water; thus bridging the gap of service in urban and rural areas. The present research seeks to use the domestic wastewater treated in the production of concrete for construction; the results show slightly for the slump, initial setting time and splitting tensile increase, and that the resistance to compression and flexural is decreased.
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  • Influence of cement on concrete mix designs through sustainability indicators

    Gil, Lucero; Ruiz, Sheyla; Rodriguez, José; Vise, Juan (Trans Tech Publications Ltd, 2022-01-01)
    Internationally, the most widely used concrete mix design methods are the American Concrete Institute, Department of Environment, Indian Standard, Fineness Modulus and Walker. These methods propose the dosage of materials from tables and graphs developed from multiple experiments and generalize the designs to achieve optimum strength, durability, and quality performance. However, sustainability does not contemplate the design, especially cement, which is responsible for CO2 emissions and the cost of concrete. The study analyzed the procedure and dosage of five methods for a 20 MPa strength concrete mix in the laboratory and applied them to beams and columns in a multi-family building using sustainability indicators. The results indicate that the IS method uses water efficiently, is more economical, and requires less cement, while the ACI method generates a positive environmental and social impact due to the efficient consumption of materials.
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  • Stability analysis using the finite element method of a slope in the Virgen de Fátima Sector of the San Juan de Lurigancho district of Lima, Peru

    Carrizales, N.; Rodriguez, R.; Vasquez, J. (Springer Science and Business Media Deutschland GmbH, 2022-01-01)
    The geometric alteration of slopes is a reality that can be observed in several districts of the Peruvian capital. The construction of houses, roads, and other infrastructure can produce some slope instability and cause tragic events. Thus, a stability analysis was carried out for a slope located in the San Juan de Lurigancho district, specifically in the Virgen de Fátima sector. Therefore, for the present investigation, two models were made with the help of Phase2 software to identify the resistance reduction factors (SFR), which is a finite element-based program. To start the analysis, possible failures were identified, demonstrating that the slope does not present any possibility of failure. For the first model, we worked with a dip of 30° and identified an SFR = 19.26 for static conditions and an SFR = 9.66 for pseudo-static conditions. For the second model, we worked with a dip of 55°, this change in slope geometry shows a possible wedge failure, according to the kinematic analysis. Also, an SFR = 0.89 was identified for static conditions and an SFR = 0.48 for pseudo-static conditions. The results show very considerable changes and are due to the geometry of the slope, the presence of discontinuities, and the participation of seismic forces.
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  • Measuring the impact of pedestrian flow on vehicle delays for a proposed DLT intersection with two displaced left turns in an urban commercial area

    Acuña, B. E.; Amaya, L. C.; Sanchez, A. M. (Springer Science and Business Media Deutschland GmbH, 2022-01-01)
    This study evaluates the impact of pedestrian flow through vehicular delays in a proposed DLT intersection located in an urban area with a high vehicular and pedestrian traffic volume. In addition, it evaluates the pedestrian–vehicle conflict points, the effect on the other accesses after the implementation of the displaced left turns, and the consequences of reorganizing pedestrian flow. Three scenarios are evaluated through microsimulation; the existing one, which is a conventional cross-shaped intersection; a proposed DLT intersection with two displaced left turns on adjacent accesses; and a third one, similar to the last one, but with the inclusion of a pedestrian underpass. Results indicate that a proposed conventional DLT increases the vehicle delays of the intersection by 6.0% compared to the existing condition, mainly due to the high volume of pedestrians and the conflicts it generates. However, with the inclusion of a pedestrian underpass, vehicle delays are reduced significantly by up to 34.0%.
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  • Influence of PET fibers on compressive strength, water absorption percentage and density of adobe

    Ordoñez, Denys; Noa, Melisa; Carrera, Elsa (Trans Tech Publications Ltd, 2022-01-01)
    Adobe is a building material that has been used since ancient times, but is not as widely used as clay bricks or concrete for housing construction. In addition, it uses a construction technique that has been passed down and improved from generation to generation. In view of this, the present work aims to improve the properties of adobe by using PET bottle fibers in its composition. A mechanical test and two physical tests were carried out for adobe with 0% (standard adobe), 2%, 4% and 6% PET fibers, where it was observed that the adobe with 6% PET fibers obtained the best results, since it increased the compressive strength of the adobe by 19%, reduced the absorption percentage by 12% and finally reduced the density by 16.4%. Therefore, the addition of PET fibers in adobe is recommended, as it contributes to improve its mechanical and physical properties. Additionally, it reduces pollution in streets, rivers, parks, etc. because it promotes the recycling of PET bottles.
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  • Comparative seismic behavior the retrofit of 60year old hospital between CFRP materials and concrete walls by nonlinear static analysis

    Criales, Xiomara; Altamirano, Anilú; Huaco, Guillermo (Trans Tech Publications Ltd, 2022-01-01)
    The Casimiro Ulloa Hospital is a confined masonry structure more than 60 years old that does not satisfy the requirements of the Peruvian seismic code E.030 and it is located at high seismic zone. Therefore, this hospital is susceptible to collapse and becomes an essential deficient structure. Therefore, the present study is based on a comparative analysis between reinforced concrete wall and CFRP sheets through the nonlinear Push Over method in order to obtain which is the best reinforcement in structural capacity. The reinforcement with eight L-shaped concrete walls of 15 cm thick located at the corners of the structure, increased the strength of the hospital by 115% in longitudinal direction (Axis X) and 108% in transversal direction (Axis Y), and also increased the ductility by 3% and 117% in the directions respectively. The other reinforcement was carried out with CFRP sheets and anchors. The sheets were designed with a width of 9 inches and were placed in an X-shape in the masonry load-bearing walls and the anchors were implemented in the corners of the laminate walls in order to ensure adequate load transfer between the sheets and the surface. This reinforcement increased the strength of the structure by 345% in axis X and 150% in axis Y and increased the ductility by 59% in longitudinal direction and 331% in transversal direction.
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  • 3D semi-analytical solution of hygro-thermo-mechanical multilayered doubly-curved shells

    Monge, J. C.; Mantari, J. L.; Arciniega, R. A. (Elsevier Ltd, 2022-04-01)
    In this paper, a three-dimensional bending solution of doubly-curved shells subjected to mechanical, thermal and hygrothermal load is studied. Through-the-thickness temperature of the shell is modeled by Fourier's heat conduction equation. Fick's moisture diffusion law equation is used to determine the hygro-thermal profile through-the-thickness. The partial differential equations are solved by using the Navier closed form summations which are valid only for shells with constant radii of curvature among the midsurface and with simply supported boundary conditions on its shell's edges. The shell governing equations are solved by discretizing the thickness profile via Legendre's grid distribution and by using the Differential Quadrature Method (DQM). The Layerwise capabilities of the method is guaranteed by imposing the inter-laminar continuity of out-of-the-plane stresses, displacements, temperature and hygrothermal load thickness profile. The zero-stress condition for the transverse shear stresses is imposed due to the fact that no mechanical loads are applied in those directions. Results for cylindrical, spherical panels and rectangular plates are presented. Comparisons are made with Layerwise and three-dimensional solutions available in literature. The results have strong accuracy and a benchmark problem is delivered.
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  • Analysis of human physical vulnerability using static equilibrium techniques of a Hazard flood for the determination of unsafe areas in the city of Catacaos - Piura, Peru

    Carrizales, J. A.; Rodas, M. C.; Castillo, L. F. (IOP Publishing Ltd, 2022-01-06)
    Heavy rains and El Nio phenomenon are recurring natural phenomena at a national level. These can cause floods due to the overflowing of rivers, which, when close to cities, can cause both human and material losses. The district of Catacaos, located in the city of Piura, was the one with the highest number of injuries due to the flood caused by El Nio phenomenon in 2017. This phenomenon causes a large amounts of rainfalls due to the presence of abnormally warm waters along the northern coast of Peru [1]. It is for this reason that the need arose to carry out an analysis of the physical vulnerability due to instability of people through static equilibrium, in said district, in order to present maps of unsafe areas in the face of this phenomenon. In this investigation, flood hazard maps are generated simulating the one presented in 2017, using 2D hydraulic modeling. For the generation of vulnerability curves, the instability analysis is performed by moment and drag force. Finally, maps with unsafe areas are made using ArcGis software. Where the results obtained indicate that 29.37% of the city was flooded. Likewise, the vulnerability maps generated show us that women and men over 18 years of age in the city of Catacaos would be vulnerable to dragging and overturning in the face of floods in 16.54% and 13.21%, respectively, of the total studied area. This information will be useful for the development of future evacuation plans during floods, carried out by national entities. © Published under licence by IOP Publishing Ltd.
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  • Influence of the types of grass of green roofs for the design of thermal comfort in buildings

    Rodríguez, José; Vilela, Karina (Polskie Towarzystwo Inzynierii Ekologicznej (PTIE), 2022-01-01)
    The main objective of the research was to study the effect of the Stenotaphrum secundatum and Zoysia japonica grasses on the higher and lower environment temperature and lower relative humidity; the secondary objective was to compare whether the Stenotaphrum secundatum grass has a greater impact on the environment parameters of comfort than the Zoysia japonica species. Six materials were used for the extensive green roof, each one forming a layer of the system, which were placed on the concrete slab and in an upward direction, including: PVC geomembrane, Polyester asphalt carpet, Pumice stone, Planar geodren, Prepared soil with guano, compost, muss, and Substrate. In order to make measurements of the higher and lower ambient temperature, a digital thermometer and lower relative humidity meter was used. Stenotaphrum secundatum and Zoysia japonica were used as grass species, as they were the most representative of the grasses used in extensive green roofs. The experimentation was carried out for 2 months from September to October of 2021, having built 3 modules of 1000x600mm roofs, including 1module of the concrete roof with ceramic covering and 2 modules of extensive green roof with two types of grass: Stenotaphrum secundatum and Zoysia japonica. The readings of the environment temperature and relative humidity of the higher and lower part were taken in six points of each module to have a greater number of representative measurements. The watering of the 2 green roof modules with grass was carried out twice a week, applying 5L of water per module. The results indicate that the Zoysia japonica grass is the one that presents a better behavior before the higher ambient temperature and that the Stenotaphrum secundatum grass behaves better before the lower ambient temperature and lower relative humidity. The conclusions indicate that the Stenotaphrum secundatum grass behaves better temperature and relative humidity; the two grass types exhibit different behavior.
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  • Vulnerability curves for masonry buildings affected by hyperconcentrated flows as natural disaster risk management tools for the quantification of material damage

    Jara, A.; Quispe, T. Y.; Castillo, L. F. (IOP Publishing Ltd, 2022-01-06)
    The damage assessment caused by floods, earthquakes, hurricanes among others phenomenons in the world are analyzed with methodologies such as "Vulnerability curves". In Peru, disasters caused by hyperconcentrated flows are alarming due to a climatic variability such as the "El Nio Costero"phenomenon. Therefore, this research has developed vulnerability curves for 1 and 2-story confined masonry buildings in Urb. San Idelfonso, Ica - Peru; linking the variables: flow depth, associated with the event produced by heavy rains at the top of the "Quebrada Cansas"caused by the "El Nio Costero"phenomenon in 2017, and the percentage of the damage based on the methodology of the United States Army Corps of Engineers (USACE), whose formula is the repair value and total building value. The monetary amounts and items of the buildings are obtained from the RM 415-2017-VIVIENDA of the Ministry of Housing, Construction and Sanitation of Peru. The process consisted of hydrological modeling in HEC-HMS, hydraulic modeling in FLO-2D, damage percentage estimate and vulnerability curves production. Finally, the vulnerability curves for hyperconcentrated flows were contrasted with similar studies regarding curves for flooding and debris flow. The results of the investigation showed that the "El Nio Costero"phenomenon in 2017 had an economic impact of at least 1.3 million soles in Urb. San Idelfonso. In addition, at least 24 buildings had a complete damage and 21 buildings an extensive damage.
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  • Evaluation of the Effectiveness of Flexible Debris Flow Barriers for Control of Huaycos Using Satellite Images and GIS, in the Basin of Rímac River, Perú

    Pareja Dominguez, Marco Antonio; Pascual Figueroa, Henry Douglas; Silva Dávila, Marisa Rosana (Springer Science and Business Media Deutschland GmbH, 2022-01-01)
    Recurrent economic and human losses occur in populated areas caused by the debris flow, known in Peru as “huayco” and for which there is little information. To determine the effectiveness of debris flow barriers installed in 2016 in three high-risk creeks with slopes ranging from 29 to 35%, it was analyzed satellite images with the Geographical Information System (GIS). For that, it is necessary to obtain the volumes of both soil erosion in the upper basin transported by the debris flow and the retained solids by the barriers. Topographic, geological, geomorphological, and hydrological characteristics were evaluated, as well as the evolution of the population in the dejection cone. It was no possible to obtain results for all the destructive events because there are no cartographies, and the available satellite images do not have enough temporal or spatial resolution or present cloudiness greater than 20%. The field investigations after the ENSO 2017 occurrence made it possible to verify that the debris flow barriers allowed to avoid the loss of human life and material damage. The field measured volumes of the solids retained by the barriers and the previously estimated volumes of erosion were compared, and retention efficiency of 80–90% was obtained. It recommends continuing with this research because it is necessary to know debris flow characteristics for analyzing the convenience and technical requirements for the implementation of retention barriers in other dangerous streams that are difficult to access.
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  • Buckling analysis of laminated composite beams by using an improved first order formulation

    Ayala, Shammely; Vallejos, Augusto; Arciniega, Roman (Trans Tech Publications Ltd, 2021-01-01)
    In this work, a finite element model based on an improved first-order formulation (IFSDT) is developed to analyze buckling phenomenon in laminated composite beams. The formulation has five independent variables and takes into account thickness stretching. Threedimensional constitutive equations are employed to define the material properties. The Trefftz criterion is used for the stability analysis. The finite element model is derived from the principle of virtual work with high-order Lagrange polynomials to interpolate the field variables and to prevent shear locking. Numerical results are compared and validated with those available in literature. Furthermore, a parametric study is presented.
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