Browsing by Author "Hernández López, Héctor Enrique"

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    Circular economy in the built environment: A systematic literature review and definition of the circular construction concept
    (2023) Ossio Castillo, Felipe Antonio; Salinas Gutiérrez, Carlos Alfonso; Hernández López, Héctor Enrique
    The Circular Economy (CE) has become increasingly important across various industries. It challenges the traditional take-make-dispose approach and aims to maximize economic value while reducing waste. However, the construction industry is still in the early stages of adopting this concept, and a clear and unified definition is needed for Circular Construction (CC) in the built environment. Without a comprehensive understanding, the CE principles and practices may be misapplied, leading to inefficiencies. To address this, a Systematic Literature Review of 316 publications was conducted to bridge knowledge gaps and to propose a definition for CC. The study identified five clusters of conceptual affinities and nine attributes that contributed to the CC definition. The results suggest that the CC concept is mainly related to the conceptual affinities of Construction and Demolition Waste Management (CDWM) and the “R" strategies, that the environment is prioritized over economic and social aspects, and that CC research focuses on building over other infrastructures, especially on aspects of building disassembly and reversibility. Still, despite these advances, most research lacks a holistic view of the application of the concept. Practitioners looking to promote cleaner construction practices can benefit from this study’s valuable insights, helping to guide decision-making and prevent the misuse of the circular economy concept in the built environment.
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    Valorization of Recycled Aggregate and Copper Slag for Sustainable Concrete Mixtures: Mechanical, Physical, and Environmental Performance
    (2024) Caballero Arredondo, Pamela Wendy; Silva Urrego, Yimmy Fernando; Araya Letelier, Gerardo Andrés; Hernández López, Héctor Enrique
    The increasing environmental impacts caused by the high demand for concrete production have underscored the need for sustainable alternatives in the design of eco-concrete mixtures. Additionally, important industries, such as construction and mining, generate massive amounts of waste/by-products that could be repurposed towards sustainability. Consequently, this study investigates the valorization of copper slag (CS), a by-product of the mining industry as a supplementary cementitious material (SCM), and concrete as recycled coarse aggregate (RCA), derived from construction and demolition waste, as partial substitutes for Ordinary Portland Cement (OPC) and natural coarse aggregate (NCA), respectively. Eco-concrete mixtures were designed with varying replacement levels: 15% for CS, and 0%, 20%, 50%, and 100% for RCA. The mechanical properties (compressive, indirect tensile, and flexural strengths), permeability characteristics (porosity and capillary suction), and environmental impacts (carbon footprint) of these mixtures were evaluated. The results showed that the use of CS and of increasing proportions of RCA led to a monotonic loss in each of the concretes' mechanical strength properties at 7, 28 and 90 days of curing. However, at extended ages (180 days of curing), the concrete mixtures with CS and only NCA presented an average compressive strength 1.2% higher than that of the reference concrete (mixture with only OPC and natural aggregate). Additionally, the concrete mixture with CS and 20% RCA achieved 3.2% and 5.8% higher average values than the reference concrete in terms of its indirect tensile strength and flexural strength, respectively. Finally, a cradle-to-gate life cycle assessment (LCA) analysis was implemented, whose results showed that the greatest effect on reducing the carbon emission impacts occurred due to the substitution of OPC with CS, which confirmed that the adequate technical performances of some of the concrete mixtures developed in this study are positively complemented with reduced environmental impacts. Moreover, this study presents a viable approach to minimizing resource consumption and waste generation, contributing to the advancement of eco-friendly construction materials, which aligns with the sustainable development goals.