Permeable concrete is a material that allows water filtration, reduces surface runoff, and maintains the natural water cycle. Previous studies have shown that its mechanical properties, particularly its compressive and flexural tensile strengths, are generally lower than those of conventional concrete, with significant variability observed among similar tests. This study investigates the compressive strength, flexural strength, and permeability of polypropylene fiber-reinforced permeable concrete specimens at two water–cement ratios (0.30 and 0.35). The mix design was conducted using the ACI 522R-10 method. Forty-eight cylinders measuring 200 mm × 100 mm were fabricated for permeability and compression tests. Additionally, 12 beams measuring 100 mm × 100 mm × 350 mm were produced and subjected to simple flexural testing in accordance with ASTM C78 guidelines. Compressive strength versus permeability and load versus deflection graphs were plotted, and the fracture energy was calculated for various deflections. The results indicate that the addition of fibers increased permeability and tensile strength but decreased compressive strength. Furthermore, an increase in the water–cement ratio led to higher compressive and flexural tensile strengths.

The performance-based seismic design pretends to take care of the lives of the occupants and reduce the cost of damage caused by earthquakes. Several ways of estimating damage and economic losses have been developed, but most of them lack objectivity and have great dispersion in the results. In the last decade, the advancement of technology has allowed the appearance of new methodologies, such as the one developed by the Pacific Earthquake Engineering Research Center (PEER methodology). However, the information regarding application and scope is scarce. In the present investigation, the economic seismic performance for a steel building was determined by applying the PEER methodology with different levels of seismic intensity. A multi-family residential model of special moment frames (SMF) was used, and the structure was designed by means of modal analysis. Spectral, incremental dynamic non-linear analysis was performed where the structural response was determined, with the help of the PACT software. The seismic performance, expressed as the repair costs, repair times, deaths, and injuries, was defined. The results obtained indicate that buildings designed with traditional structural standards can be demolished after the action of an earthquake because the repair costs exceed 40% of the replacement cost. Rare and very rare seismic events can cause the total suspension of the service and a considerable number of deaths and injuries.

The objective of this work was to design and implement a system based on reconfigurable hardware as a study tool for the synchronization of chaotic circuits. Mathematical models were established for one circuit, two synchronized, and multiple synchronized Chua circuits. An ordinary differential equation solver was developed applying Euler’s method using the Verilog hardware description language and synthesized on a Spartan 3E FPGA (Field-Programmable Gate Array) equipped with a 32-bit RISC processor, 64 MB of DDR SDRAM, and 4 Mb of PROM. With a step size of 0.005 and a total of 10,000 iterations, the state equations for one and three Chua circuits were solved at a time of 0.2 ms and a frequency of 50 Mhz. The logical resources used by the system did not exceed 4%. To verify the operation, a numerical simulation was carried out using the Octave V9.1.0 calculation software on an Intel(R) Core i7-9750H CPU 2.59 GHz computer, obtaining the same results but in a time of 493 ms and 3.177 s for one and three circuits, respectively.

Research on the relationship between structural characteristics and vibration periods in concrete buildings is crucial to ensure the safety and efficiency of these structures, especially in earthquake-prone areas. This article aims to analyze and compare the impact of structural stiffness of different elements, such as beams, columns and shear walls, on vibration periods, through a systematic review of existing models and formulas in the literature, identifying their applications and limitations. The methodology used consists of a systematic review that integrates recent and relevant studies, providing a solid basis for analysis. The results indicate that an increase in the stiffness of structural elements can reduce vibration periods by 20–50%, implying a faster response to external forces. Even in low-rise buildings, the fundamental period can be reduced by 53% to 70%. These findings are significant for the design and construction of concrete buildings, as they suggest that incorporating rigid structural elements can improve seismic resistance and reduce the risk of damage. In addition, the research contributes to the field of structural dynamics by highlighting the need to integrate different methods of analysis and evaluation. It is recommended that engineers and architects adopt innovative approaches, such as the use of emerging technologies and monitoring methods, to improve damage detection and optimize structural design. Finally, it identifies areas where more research is required, suggesting that future studies should explore the interaction between structural characteristics and environmental conditions for a more complete understanding of the vibrational behavior of buildings.

The escalating global imperative for sustainable waste management has prompted innovative research into valorizing organic waste streams in construction materials. This study investigates coffee bagasse (BC) as a potential fine aggregate replacement in concrete, addressing both environmental challenges and material performance optimization. Through systematic analysis, the effect of coffee bagasse incorporation as fine aggregate in the compressive resistance of concrete was studied. Coffee bagasse was processed in raw and pyrolyzed states and incorporated into concrete mixtures at 5%, 10%, and 20% volume replacement levels. Differential scanning calorimetry (DSC) and comprehensive compressive strength assessments were carried out to analyze the performance and behavior of the material. The findings revealed critical insights: raw coffee bagasse lixiviation significantly impaired cement hydration, negatively affecting concrete mechanical properties, whereas pyrolysis at 349.5°C transformed BC into coffee biocarbon, yielding a remarkable 22.39% increase in concrete compressive strength. The thermal treatment emerged as a pivotal intervention for effective waste material integration, demonstrating a promising pathway for converting agricultural by-products into high-value construction materials. By bridging waste management strategies with material science innovation, this research contributes to circular economy principles, offering a sustainable approach to reducing waste and enhancing infrastructure material performance through advanced thermal processing techniques.