This study examines the impact of mix design parameters on the environmental effects of producing concrete and reinforced concrete buildings by conducting a life cycle assessment (LCA) and carbon footprint analysis (CFA). The study is limited to the cradle-to-gate phase, including the extraction and production of raw materials for concrete production, as well as concrete and rebar production, material transportation, and delivery to the construction site for reinforced concrete structures. Three concrete mix designs based on the American Concrete Institute (ACI) 211-09 standard, with compressive strengths of 20, 30, and 40 MPa, were analyzed. The results indicate that cement was the primary contributor to environmental impacts, accounting for approximately 90% of the carbon footprint. Sand, gravel, and admixtures followed cement in their impact on LCA results. Water usage in concrete production had a negligible effect on LCA indicators. Moreover, to determine how mix design parameters impact the carbon footprint of reinforced concrete buildings, three four-story structures were designed. The results show that in reinforced concrete buildings, concrete was a significant contributor to environmental impacts, accounting for over 50% of all indicators in the IMPACT 2002+ and CML baseline 2000 methods, except for resources and acidification. The study underscores the importance of considering mix design parameters in reducing the carbon footprint of reinforced concrete buildings and provides valuable insights into their environmental impacts. The findings indicate that cement is the main driver of environmental impacts in both assessment methods, accounting for around 90% of the carbon footprint. Additionally, concrete plays a substantial role in environmental effects, contributing to over 50% of all indicators measured in the methods used for evaluating environmental impacts.

In modern construction, increasing the sustainability of materials without sacrificing performance is crucial. Ultra-High-Performance Concrete (UHPC) is known for its exceptional strength and durability. However, incorporating waste and optimizing the mix is still a key focus. The main goal of this article is to evaluate the enhancement of the mechanical properties of UHPC by replacing silica sand with steel slag at various percentages (25%, 50%, 75%, and 100%). With this purpose, we measured the compressive, tensile, and flexural strengths, as well as relative density and water absorption. It was found that the best mechanical performance of UHPC occurs at 50% replacement, exhibiting a maximum compressive strength of 126 MPa (+13.5%), a bending strength of 11.6 MPa (+20.8%), and a tensile strength of 7.2 MPa (+6.5%). Moreover, for the same steel slag replacement, 5.1% decrease in the CO₂ eq. emissions was found. However, exceeding the 50% threshold led to a deterioration of UHPC’s mechanical properties, and the SEM images revealed that this was mainly caused by the weakened bond between the cement matrix and the aggregates. Thus, it was concluded that the use of steel slag may significantly improve the structural integrity of UHPC when the adequate replacement percentage is adopted (around 50%), being a viable alternative to traditional aggregates that also has environmental advantages (e.g., reduced carbon emissions).

The world is currently grappling with the two critical issues of global warming and climate change, which are primarily caused by the emission of greenhouse gases. The construction industry and buildings significantly contribute to these emissions, accounting for roughly 40% of the total greenhouse gas emissions. In response to this pressing issue, environmental organizations and governments have pushed the construction industry to adopt environmentally friendly practices to reduce their carbon footprint. This has led to a greater emphasis on designing and planning sustainable buildings that are in line with the principles of sustainable development. Hence, it is imperative to evaluate buildings in terms of their greenhouse gas emissions and explore ways to reduce them. This research examines the impact of material selection on the carbon footprint of reinforced concrete buildings, aiming to reduce embodied carbon. For this purpose, two reinforced concrete buildings are designed for their embodied carbon to quantify their environmental impact. The first building employs commonly used materials such as ceramics, clay bricks, stone, and plaster. In contrast, the second building incorporates sustainable materials such as cork, plywood, and rockwool. According to the findings, using sustainable materials in the second building leads to a 41.0% reduction in the carbon footprint of the construction process. Additionally, using sustainable materials can mitigate pollution levels in the three categories of endangerment to human health, ecosystem pollution, and resource consumption by 31.4%, 23.7%, and 33.3%, respectively.

Examining the life cycle of structures, such as concrete dams, holds paramount importance for engineers, as it facilitates a comprehensive assessment of overall sustainability, enabling the balancing of the benefits and costs associated with dam development. The recycling of materials emerges as a crucial factor in mitigating environmental impacts. This study employs the IMPACT 2002+ methodology to perform a life cycle assessment (LCA) of a concrete dam, covering the stages from construction to decommissioning. Additionally, carbon footprint analysis (CFA) and life cycle costing (LCC) are performed to pinpoint greenhouse gas (GHG) emission sources and access economic performance. This investigation spans three key-stages: (1) initial construction; (2) decommissioning; (3) hypothetical scenarios with recycling rates for demolished concrete and steel, evaluating how different recycling percentages influence both the environmental benefits and LCC outcomes. The results emphasize the significance of reducing air pollution, with climate change identified as the primary environmental concern compared to ecosystem and resource indicators. The findings show that the carbon footprint associated with the construction of 1 m width of the dam is estimated to be around 355 ton CO₂ eq. Furthermore, the total carbon emissions resulting from the demolition of the dam were identified to amount to 735 ton CO₂ eq/m. The recycling of the dam materials after demolition led to a notable reduction in pollution associated with the decommissioning process of the dam, compared to the dams’ destruction without recycling.

High-performance and ultra-high-performance fiber-reinforced concretes (HPFRC/UHPFRC) have emerged as advanced cementitious composites capable of achieving superior mechanical performance, durability, and structural efficiency compared with conventional concrete. However, their widespread adoption remains challenged by relatively high material costs and significant embodied environmental impacts associated with elevated binder and fiber contents. This study presents a comprehensive life-cycle review of advanced high-performance cementitious composites, evaluating their sustainability from raw material extraction and mix design to structural application, service life, and end-of-life considerations. The review synthesizes current knowledge on material composition, production processes, structural performance, durability characteristics, and environmental impacts through the framework of life-cycle assessment (LCA). Particular attention is given to the influence of mix-design parameters, including binder composition, supplementary cementitious materials (SCMs), aggregate systems, and fiber type, on embodied carbon, energy demand, and mechanical performance. A dataset compiled from published experimental studies covering high-performance and ultra-high-performance concrete mixtures is analyzed to examine relationships between compressive strength, embodied energy, and carbon footprint, highlighting the dominant role of cementitious binders and fiber production in environmental impacts. Although advanced fiber-reinforced concretes generally exhibit higher cradle-to-gate emissions than conventional concrete, their superior mechanical properties, improved durability, reduced material demand, and extended service life can substantially reduce life-cycle environmental impacts at the structural level. The review further discusses emerging strategies for developing low-carbon high-performance cementitious composites, including clinker reduction, recycled and alternative fibers, optimized particle packing, and AI-assisted mix design. Finally, key research gaps are identified, particularly regarding standardized LCA methodologies, long-term durability data, harmonized performance-based functional units, and circular-economy strategies for material recycling and reuse. The findings highlight that performance-based life-cycle evaluation is essential for accurately assessing the sustainability potential of advanced high-performance cementitious composites in resilient and low-carbon infrastructure systems.