Aprovechamiento de los RCD de muelle expuesto en ambientes marinos en cartagena

Sustainable management of concrete demolition waste is a critical challenge in mitigating the environmental impacts associated with construction. This project focuses on assessing the reuse potential of Demolition Waste from a Pier located in a marine environment, integrating sustainability into the material and process life cycle in accordance with national and international standards. The initiative aims to develop sustainable solutions aligned with the circular economy while addressing material quality and feasibility for new applications. The methodology for this project was organized into four main phases. In the first phase, a comprehensive review of literature and applicable regulations was conducted to identify relevant standards. In the second phase, waste materials were characterized through destructive and non-destructive tests to analyze their physical, chemical, and mechanical properties. The third phase involved technical evaluation of the feasibility of recycled materials in the context of sustainability. Finally, the fourth phase focused on developing alternatives based on circular economic principles, proposing actionable strategies for implementation. The extracted concrete cores exhibited compressive strengths ranging from 11.8 MPa to 33.9 MPa, with an average of 23,6 MPa, exceeding 85% of the design strength (17,85 MPa, as per NSR-10). However, 33% of the samples fell below 75% of the design strength (15,75 MPa), suggesting material quality inconsistencies across different areas of the pier. The average total porosity of 3.3% indicates a compact and dense structure, favorable for strength and durability in aggressive environments. Additionally, tests conducted per ASTM C856-20 revealed no significant signs of carbonation, confirming adequate protection against CO₂ penetration. Recycled aggregates obtained showed an average absorption of 6.2%, exceeding the 5% limit set by NTC 77, which may affect the workability of mixes. The density of recycled aggregates ranged between 2.15 g/cm³ and 2.49 g/cm³, lower than natural aggregates (2.58 g/cm³ to 2.62 g/cm³) due to adhered mortar and internal porosity. While initial gradation curves did not fully comply with NTC 174, a mix combining 50% RCD and 50% natural aggregates adjusted the properties to fall within acceptable normative ranges. In RCD-based mixes, compressive strengths at 28 days were evaluated under different water/cement ratios: Water/Cement Ratio 0.67: 16.2 MPa (62% of design strength). Water/Cement Ratio 0.61: 18.5 MPa (71%). • Water/Cement Ratio 0.47: 23.3 MPa (89%). Water/Cement Ratio 0.45 (optimized): 24.5 MPa (93.5%). Mixes with 50% RCD and a water/cement ratio of 0.45 achieved an average elastic modulus of 23,263 MPa, suitable for structural applications under NSR-10. In terms of durability, chloride content was 0.074%, within the normative limit of 0.10% as per NSR-10 for aggressive environments. Sulfate tests showed SO₃ content of 1.15%, classified as acceptable, though monitoring is advised for prolonged exposure to humid or sulfate-rich environments. Additionally, alkali-silica reactivity tests demonstrated expansions below 0.10% at 16 days (ASTM C1260), classifying the recycled aggregates as non-reactive. The project demonstrates that, with appropriate adjustments to mix design and optimal RCD proportions, it is possible to develop sustainable concrete with suitable properties for structural applications in aggressive environments.

• Autores: Mendoza Martínez, Gustavo Adolfo
• Fecha de publicación: 2024
• Institución: Corporación Universidad de la Costa
• Repositorio: REDICUC - Repositorio CUC
• Idioma: spa
• OAI Identifier: oai:repositorio.cuc.edu.co:11323/14047
• Acceso en línea: https://hdl.handle.net/11323/14047; https://repositorio.cuc.edu.co/
• Palabra clave: Resistencia a compresión; Relación agua/cemento; Agregados reciclados; Durabilidad en ambientes marinos; Compressive strength; Water/cement ratio; Recycled aggregates; Porosity - Durability in the sea
• Rights: openAccess
• License: Atribución-NoComercial-CompartirIgual 4.0 Internacional (CC BY-NC-SA 4.0)