Ingeniería Civil y Mecánica
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Item Análisis de la resistencia a compresión del hormigón simple con agregado grueso reciclado y craqueo catalítico fluidizado en reemplazo del agregado fino(Ingeniería Civil y Mecánica. Carrera Ingeniería Civil, 2025) Espinoza Castro María José; Navarro Peñaherrera Carlos PatricioThis experimental study evaluates the compressive strength of plain concrete by incorporating recycled coarse aggregate (RCA) and spent fluid catalytic cracking (FCC) catalyst as a replacement for fine aggregate. This research responds to the growing need to promote sustainable practices in construction, optimize resources, and reduce the environmental impact generated by the extensive use of natural materials. The methodology was developed in three phases: characterization of the physical and mechanical properties of recycled aggregates, comparison of the compressive strength of traditional concrete versus concrete with RCA and FCC, and an analysis of economic feasibility. Concrete mixtures with 100% recycled materials and 100% natural aggregates were prepared following regulatory techniques such as NTE INEN and ASTM and were evaluated using standardized tests. The results show that the use of RCA and FCC affects the workability and strength of concrete, but within acceptable ranges for certain structural uses. After 7 days, the concrete with natural aggregates reached a strength of 171.45 kg/cm², while the mix with recycled aggregates reached 37.75 kg/cm². After 14 days, the strengths were 196.55 kg/cm² and 47.47 kg/cm², respectively, and after 28 days, values of 239.74 kg/cm² were obtained for natural aggregates and 74.17 kg/cm² for recycled aggregates. These figures show that, although there is an approximately 70% decrease in the strength of recycled concrete compared to conventional concrete, it can meet structural parameters for certain non-critical applications. Furthermore, the use of recycled materials is considered not to significantly reduce the cost of concrete: the cost per cubic meter increased from $100.90 (traditional mix) to $291.77 (mix with recycled materials), which represents a significant contribution in economic terms. The study's conclusions indicate that incorporating AGR and FCC is not feasible from a technical or economic perspective, even if the proportions in the mix are optimized or the project's structural requirements are considered. However, for other uses, this approach contributes to reducing environmental impact, fosters the circular economy, and promotes responsible resource use in the construction sectorItem Análisis de resistencia a la compresión en columnas de hormigón armado elaborado con materiales reciclados(Ingeniería Civil y Mecánica. Carrera Ingeniería Civil, 2025) Matías Sebastian Shambi Ortiz; Wilson Santiago Medina RobalinoThis experimental study aimed to evaluate the structural behavior of reinforced concrete columns incorporating recycled materials, specifically by partially replacing fine aggregate with 5% spent fluid catalytic cracking catalyst (FCC) and coarse aggregate with 20% recycled coarse aggregate (RCA). The performance of these columns was then compared to columns made with conventional aggregates. A quantitative approach was developed through three main phases: physical characterization of the materials (sand, gravel, RCA, and FCC), design and fabrication of reinforced concrete columns with three types of mixtures (conventional, with RCA, and with FCC), and compression testing of the columns. The specimens were designed as columns measuring 15×15×100 cm, reinforced with four longitudinal steel bars of 7 mm diameter and 4 mm stirrups. The design considered the 20-ton capacity limit of the testing machine under axial compression. The characterization results indicated that the natural aggregates met normative requirements, whereas the RCA showed a lower density (2241.99 kg/m³) and higher water absorption (2.64%), attributed to its porosity. The FCC also presented high porosity but with acceptable particle size distribution. To ensure the quality of the concrete, control cylinders were prepared and tested at 7 and 28 days. These samples reached an average compressive strength of 252.74 kg/cm², within the expected experimental margin (±5%) for a target design strength of 240 kg/cm². The nominal axial strength of the designed column section was calculated at 53.37 Tn, with a design strength of 27.30 Tn, indicating that failure would not occur during testing due to equipment limitations. Under testing, the maximum load applied by the compression machine was 20 Tn. The measured strain values were 0.005 mm/mm for the natural aggregate columns, 0.003 mm/mm for those with 5% FCC, and 0.002 mm/mm for those with 20% RCA. These results show reduced ductility for the recycled material columns, as lower strain corresponds to more brittle behavior. It was concluded that the incorporation of FCC and RCA tends to reduce ductility despite increasing strain capacity. Therefore, further research using more robust testing equipment is recommended to validate the feasibility of applying recycled aggregates in reinforced concrete columns with greater reliabilityItem Análisis del comportamiento a flexión de vigas de hormigón armado con agregado reciclado y catalizador agotado de craqueo catalítico fluidizado sometidas a fuego(Ingeniería Civil y Mecánica. Carrera Ingeniería Civil, 2025) Chicaiza Vélez Ignacio Jesús; Medina Robalino Wilson SantiagoThis research focuses on analyzing the flexural behavior of reinforced concrete beams that incorporate recycled aggregate from construction and demolition waste along with spent fluid catalytic cracking catalyst (FCC) as a partial substitute for fine aggregate, when these elements are subjected to extreme thermal conditions of 600°C. This research line emerges as a response to the environmental problem derived from the progressive depletion of natural aggregate sources, whose intensive exploitation has generated significant alterations in ecosystems and threatens the future availability of these strategic resources. Consequently, the use of alternat ive materials is proposed that not only reduce dependence on virgin raw materials but also contribute to optimizing the management of solid waste generated by the construction industry. The experimental methodology adopted comprises three fundamental phases: initially, the physical-mechanical characterization of materials through standardized tests to determine properties such as granulometry, real density, absorption capacity, and moisture content of natural and recycled aggregates. Subsequently, nine reinforced concrete beams with dimensions of 15×15×75 cm are manufactured, using the optimal density method for dosification, where six beams incorporate recycled coarse aggregate and 5% FCC, while three beams constitute the xix control group with conventional aggregates. Three of the beams with alternative materials are subjected to controlled thermal exposure of 600°C to simulate critical fire conditions. Finally, a comparative analysis of structural behavior is performed through flexural tests according to ASTM C78 standard, evaluating flexural strength between beams with natural aggregates, beams with alternative materials without fire exposure, and those subjected to extreme thermal conditions. The obtained results will allow establishing the technical feasibilit y of these alternative materials in structural elements, simultaneously contributing to the environmental sustainability of the construction sector and the development of environmentally responsible technologies, in addition to providing more precise design parameters for future applications in civil works under extreme temperature conditions.Item Resistencia a la compresión del hormigón simple fabricado con agregado fino proveniente de hormigones reciclados(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica, Carrera de Ingeniería Civil, 2024-02) Salinas Freire, Bryan Paúl; Peñafiel Valla, Lourdes GabrielaThe integration of recycled materials in the manufacture of concrete is presented as a viable alternative to mitigate the environmental impact of the construction industry. In this study, we seek to determine the optimal percentage of substitution of recycled fine aggregate in concrete in place of natural fine aggregate, focus ing on evaluating its impact on compressive strength. The recycled material was obtained from a crushing process of laboratory specimens, sidewalk debris and curbs; both recycled aggregate and natural aggregates were subjected to analysis according to INEN standards, then the design of concrete dosages of 210 kg/cm2 and 240 kg/cm2 was carried out using the Optimal Density Method developed by the Central University of Ecuador. Subsequently, reference specimens were prepared using natural materials to compare their resistance with specimens in which the natural fine aggregate was replaced by recycled fine aggregate in percentages of 10, 15, 30, 30, 60 and 100 percent. The results show that there is a decrease in the compressive strength as the percentage of recycled fine aggregate increases. However, it is observed that replacement percentages of 10 to 30 percent can provide acceptable compressive strengths. This highli ghts the potential of recycled materials for concrete manufacturing as a promising solution to reduce environmental impact, provided that their limitations are considered.Item Influencia del fuego en la resistencia a compresión del hormigón elaborado a partir de material reciclado(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica, Carrera de Ingeniería Civil, 2023-09) Quishpe Toapanta, Byron Javier; Peñafiel Valla, Lourdes GabrielaBecause concrete is a material widely used in construction characterized by its high compressive strength, factors such as fire could cause problems in its internal and external functionality. That said, the objective of this research is to analyze the behavior that concrete with recycled aggregate will have, coming from residual concrete, whose purpose is to obtain experimental results that demonstrate how fire affects its compressive strength. For this experimental investigation, the optimal density method will be used to design the dosage with a resistance of 240 kg/cm2, within which 45 cylindrical test tubes were made, distributed 15 each with replacements of 0, 15 and 30 percent of natural aggregate by recycled aggregate. The specimens, after being cured at 28 days of age, were subjected to direct fire by means of a smelting furnace. With the help of a pyrometer, the temperatures that were exposed were controlled, which range from 0, 250, 400, 600 to 800 degrees Celsius during a determined period of time. For each temperature, 3 cylindrical concrete samples will be tested. Once exposed to the fire, they were cooled for 24 hours, to later be tested for compression. From the results obtained, it is shown that the compressive strength decreases as a function of each increase in temperature, looking unfavorable to those specimens that were replaced with 30 percent RA, in addition to this, various pathologies such as cracks, fissures, color changes and the phenomenon of chipping or spalling occurred.