This study aims at the evaluation of different formulations of concrete made with calcined clays and limestone (LC3 cement) exposed to aggressive environments. The study includes the evaluation of fresh and hardened properties and a comprehensive evaluation of durability over 24 months. The inclusion of calcined clays in cement increases the specific surface area of the cements, and thus the water demand. However, the high reactivity of calcined clays compared to any other pozzolan, and the synergy that occurs with limestones, enables the use of cements with very low clinker content that achieve strengths similar to those of Portland. Comparisons of LC3 formulations with Portland cement and with concrete containing silica fume prove the superiority of calcined clays in terms of strength and durability. The best results are obtained with LC3-50 cement with 50% clinker produced through co-grinding. Results of concrete made with a blend of 70% Portland cement with 30% LC2 (60% calcined clay, 35% limestone, 5% gypsum, separate ground) are also promising. All concretes made with LC3 show good durability in terms of the results of effective porosity, chloride permeability, and resistivity tests.
16 December 2024 in Journal of Sustainability Research
El objetivo de esta investigación fue la reducción de las trazas de materia orgánica en el agua potable por medio del uso de zeolita natural, zeolita activada y la comparación con la eficiencia de la adsorción del carbón activado. Se utilizó agua suministrada por la compañía AGUAPEN E.P. y materiales adsorbentes zeolita natural, zeolita activada y carbón activado. La zeolita se activó térmicamente a 600ªC. Se realizaron pruebas en columnas de adsorción a escala (RSSCT – Rapid Small-Scale Column Test) para carbón activado granular (GAC) de acuerdo a la norma ASTM 6586 para determinar la eficiencia de la adsorción de las trazas de materia orgánica en el agua potable. Se determinó la eficiencia en base al parámetro de carbono orgánico total en muestras simple del afluente y efluente del agua tratada cada 3 horas durante 24 horas. El incremento de la presión de trabajo evidencia el punto de ruptura o colmatación del adsorbente. La concentración del Carbón Orgánico Total (COT) se determinó mediante el análisis de la combustión de la muestra con el detector infrarrojo no dispersivo de dióxido de carbono (CO2). Los resultados mostraron reducción de materia orgánica con el uso de zeolita natural y zeolita activada, con respecto al carbón activado.AbstractThe objective of this research was the reduction of organic matter traces in drinking water through the use of natural and activated zeolite, and the comparison with the efficiency of activated carbon adsorption. Water supplied by the company AGUAPEN E.P. was used, and adsorbent materials as natural zeolite, activated zeolite and activated carbon were utilized. The zeolite was thermally activated at 600 ° C. Tests were performed on scale adsorption columns (RSSCT - Rapid Small Scale Column Test) for Granular Activated Carbon (GAC) according to ASTM 6586 to determine the efficiency of the adsorption of traces of organic matter in drinking water. Efficiency was determined based on the total organic carbon parameter in simple affluent and effluent samples of treated water every 3 hours during 24 hours. The increase in working pressure shows the point of rupture or clogging of the adsorbent. The concentration of Total Organic Carbon (TOC) was determined by analyzing the sample combustion with a non-dispersive infrared carbon dioxide (CO2) detector. The results showed the reduction of organic matter in natural zeolite and activated zeolite compared to activated carbon.
Geosites have been exploited for tourism on a small scale in Ecuador. The objective of this research is to develop a management plan that proposes strategies for the sustainability of the geosite Ancon Pozo 001, through geotourism, promoting geoeducation and geoconservation. The study stages are: i) identification of environmental and social vulnerability factors and student survey; ii) design of structures for access; iii) preparation of a management plan based on the financial analysis obtained. The results indicate the existence of displacement by planar failure and marine scour as a result of waves, proposing as a preventive measure the construction of a breakwater; the Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis shows the strengths, opportunities, weaknesses and threats that the geosite and the community have in the Ancón Pozo 001 geosite. The sectional governments do not have empowerment plans due to a lack of knowledge of the value of this site because it is considered a national cultural heritage site and the unique geology of which it is composed. The proposed management measures include building an entrance road, placing railings on the lookout esplanade, and stairs to access the beach as the basis for infrastructure and strategies for access, protection, and development.