Juan Figueroa

The construction sector faces increasing pressure to decarbonize, as embodied emissions from structural materials often dominate the environmental footprint of reinforced concrete (RC) buildings. Although reinforcement ratios are key drivers of structural capacity, their environmental implications under seismic design remain insufficiently quantified. This study investigates the relationship between longitudinal reinforcement ratios and both seismic performance and life-cycle environmental impacts in RC frame buildings. Three code-compliant reinforcement configurations (1%, 3%, and 5%) were analyzed for three- and nine-story structures designed under Eurocode 8. Mechanical performance was evaluated using nonlinear pushover analysis, while embodied impacts were quantified through Life Cycle Impact Assessment (LCIA) using the ReCiPe 2016 midpoint and endpoint methods. Results show that increasing steel content reduces concrete volume and increases lateral capacity, but may significantly decrease ductility and increase environmental burdens. Optimal performance is achieved with moderate reinforcement ratios, which reduce embodied impacts while preserving seismic safety. Furthermore, reducing the amount of concrete while increasing the amount of steel reduces the weight of structures by between 19% (3 stories) and 22% (9 stories), improving their seismic resistance due to the reduction in seismic forces in areas of moderate seismicity. These findings demonstrate that reinforcement selection introduces a measurable trade-off between structural integrity and sustainability, providing designers with quantitative guidance for low- and medium-rise RC buildings in seismic regions.

Los componentes de los neumáticos no son biodegradables, por lo tanto, afectan el ambiente donde están depositados y constituyen un peligro, por generar focos de incendios en áreas de depósitos, generando enormes nubes tóxicas con gases como lo son el monóxido de carbono, dióxido de carbono y dióxido de azufre. Con el fin de revalorizar estos residuos, la propuesta de este trabajo es utilizar el neumático triturado en pequeñas partículas en la confección de ladrillos artesanales. La fabricación fue realizada de manera manual en la ciudad de Cauquenes (Chile) por un grupo de ladrilleros y la incorporación del caucho fue en reemplazo de un volumen específico de la arcilla, precisamente en 10% y 20%, quedando de este modo tres tipos de ladrillos, considerando el ladrillo base con su composición de 100% arcilla. Los resultados arrojaron que los ladrillos con 10% de caucho tuvieron el mejor desempeño, ya que tienen una resistencia a la compresión de 4,39 MPa superando en un 4,03% a la muestra patrón, cumpliendo el 22% máximo de absorción de agua obteniendo un 18,01% y su conductividad térmica es un 28% menor que el ladrillo tradicional, por lo que sería una excelente alternativa ecológica y sustentable.

This article focuses on the research of gas emissions in two types of brick kilns located in the Maule Region, Chile. One of them is an artisanal brick kiln known as a “chonchón” (AKC), while the other is a semi-artisanal brick kiln with an improved design. The latter is referred to as the Ecokiln. This study focuses on the assessment of the emission profiles of key pollutants such as particulate matter (PM), CO, CO₂, SO₂, and NOx. The emission measurements of gasses, temperature, and flow were conducted during the operation of the kilns. These measurements were carried out following the protocol established by Chilean standards. The Ecokiln’s design facilitates optimal fluid dynamics. In direct comparison to the AKC, it exhibits reduced fuel consumption, shorter operation periods, an increased brick processing capacity, decreased burnt brick losses, and notably lower emissions, with a concentration of SO₂ that is 83% less than that of the AKC, NOx emissions, 58% lower than the AKC, and a remarkable 74.3% reduction in PM10 emissions. Moreover, the Ecokiln reduces pollutant emissions, improving the well-being of brickmakers and their communities. These results offer insights into the environmental impact of local brick production and support sustainable manufacturing practices.

A large part of the global brick manufacturing industry has evolved based on knowledge transmitted from generation to generation without developing a consistent scientific approach. The purpose of this article is to contribute to this approach by discussing the state-of-the-art and future trends of the design and construction of artisan brick kilns (ABK). The methodology proposed for this study is based on a systematic literature review whereby main question is: What research exists on brick kilns? Based on the results of this review, it is recommended that appropriate emerging technologies that should be incorporated to ABKs for either medium or small enterprises should be: mechanical fans, envelope thermal insulation, organic waste of uniform size as fuel, automatic control of process variables and computer simulations of phenomenological processes. This should be accompanied by technical training for the brick-makers and greater access to financing funds. The technologies reviewed throughout the paper will allow for a more thermally efficient design of kilns, which will emit less hazardous greenhouse gases and atmospheric pollutants.

Tires are an industrial waste that has become a worldwide environmental problem. To minimize this effect, tire waste is used in construction as a concrete aggregate. Additionally, carbon dioxide in the atmosphere affects the carbonation of concrete. This study analyzes the effect of carbonation in concrete with tire rubber aggregate as a 0%, 10%, 20%, 30%, 40%, 50% and 60% proportional replacement for the fine aggregate. The carbonation test was conducted for 2, 4, 6 and 24 hours. The compressive strength of the concrete decreased depending on the tire rubber content in the mixes, while the concretes with tire rubber percentages greater than 30% were affected by carbonation.

Construction is one of the productive sectors that generates the greatest environmental impact, on the one hand, there are high demands for raw materials and energy required for production, and on the other hand the large amount of solid waste is generated. In Chile, construction waste management is becoming a problem mainly due to the lack of planning for proper final waste management, wasting potentially reusable, recyclable or recoverable material. Knowing how to manage construction and demolition waste contributes to improving quality and production in construction work as well as maintain a responsible attitude towards the environment. This research study seeks to evaluate waste generation in a residential building work, to deliver proposals for improvements in the final disposal of these, through the creation of a methodology to quantify the waste production. In conclusion, submitting proposals for improvements for the implementation of a waste management system helps to achieve an activity within the construction sector, whose main objective is to contribute to a more sustainable construction through an adequate final disposal of waste generated in the construction process.

The behaviour of mussel shell particulate as fine aggregate for mass concrete has been analysed. The shells were washed and mechanically crushed to obtain a particle size similar to that of the natural aggregate (fine) to be replaced, which was dried at 140 °C. The Faury-Joisel method was used to design the H-35(95)-20-6 structural mass concrete sample, with 0%, 10%, 30% and 60% replacements of fine aggregate by mussel shell particulates, performing compressive strength and thermal conductivity analyses at 7 and 28 days. The results indicate that in order to maintain the compressive strength of H-35(95)-20-6 structural mass concrete, the replacement percentage should not exceed 40%. On the other hand, as the mussel shell particulates in the concrete increase, the thermal conductivity decreases, turning into a material with a tendency to increase thermal insulation, which would help to improve the new demands on energy saving and efficiency in households, if used as coating. Hence, it can be concluded that it is feasible to replace fine aggregate with mussel shell particulate matter, which would be useful in increasing the recycling of this residue and in reducing its natural exploitation.

Traditional nixtamalization is performed to produce corn flour and tortillas. This process has undergone several modifications for industrialization purposes. Extrusion is an industrially used process for nixtamalization and ohmic heating may be considered an alternative. For this study, a continuous ohmic heater was used to produce nixtamalized corn flour and the effects of the process parameters – process temperature, feed moisture, and screw speed – on the physicochemical and textural properties of dough and tortilla were reviewed. Data showed that the process temperature had a greater effect than the feed moisture on the resulting product, while screw speed did not appear to have any significant influence on this. Tortillas showed good quality characteristics because of good water absorption and retention during the process. The products obtained by continuous ohmic heating process show quality characteristics similar to those present in traditional corn flour products.