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The concrete sector is known for its significant contribution to CO2 emissions. There are two main contributing factors in this situation: the large amount of concrete consumed per year on the planet and the high levels of CO2 released from the manufacture of Portland cement, the key binding agent in concrete. To face the consequent sustainability issues, diverse strategies involving the carbon capture and storage potential of cementitious materials have been explored. This paper addresses the potential of storing CO2 in concrete during the curing stage within the context of the precast Portuguese industry. To this end, it was assumed that CO2 will become a waste that will require an outlet in the future, considering that carbon capture will become mandatory in many industries. This work concluded that, in terms of carbon retention, the net benefit is positive for the process of storing carbon in concrete during the curing stage. More specifically, it was demonstrated that the additional emissions from the introduction of this new operation are only 10% of the stored amount, returning a storage potential of 76,000 tonnes of CO2 yearly. Moreover, the overall net reduction in the concrete life cycle averages 9.1% and 8.8% for precast elements and only non-structural elements, respectively. When a low-cement dosage strategy is coupled with carbonation curing technology, the overall carbon net reduction is estimated to be 45%.

Korea revived its small-scale industry (SSI) reservation policy in the early 2010s to protect small businesses and promote their competitiveness. However, whether this size-contingent entry regulation causes allocative inefficiency remains a subject of debate. This study examines the effects of SSI reservation on both the performance of small plants and allocative efficiency in the Korean ready-mixed concrete industry. By exploiting the exogenous variation in preexisting large plants across geographically independent markets, we find that the SSI policy increases the average productivity of small plants in the affected markets. However, the policy decreases competition, thereby causing allocative inefficiency in the reserved industries.

The proliferation of Environmental Product Declarations (EPDs) for concrete and concrete-related products has seen remarkable growth since 2020, reflecting an increasing global commitment to sustainable construction practices. Concurrently, the introduction of the European standard EN 16757 for Product Category Rules (PCR) has provided a structured framework for creating EPDs that align with ISO 21930 and EN 15804, ensuring consistency and transparency. These developments underscore the need to revisit and refine ISO 13315-8, which plays a pivotal role in eco-labelling and EPDs for concrete products. This study undertakes an analysis of current EPD Standards on concrete to identify differences and characteristics among nations. By examining variations in methodologies, data quality, and regulatory requirements, the research aims to provide a comprehensive understanding of global EPD practices. These insights will inform the ongoing revision of ISO 13315-8, offering targeted recommendations to enhance its applicability and effectiveness in addressing the evolving needs of the concrete industry.

The incorporation of waste materials generated in many industries has been actively advocated for in the construction industry, since they have the capacity to lessen the pollution on dumpsites, mitigate environmental resource consumption, and establish a sustainable environment. This research has been conducted to determine the influence of different rice husk ash (RHA) concentrations on the fresh and mechanical properties of high-strength concrete. RHA was employed to partially replace the cement at 5%, 10%, 15%, and 20% by weight. Fresh properties, such as slump, compacting factor, density, and surface absorption, were determined. In contrast, its mechanical properties, such as compressive strength, splitting tensile strength and flexural strength, were assessed after 7, 28, and 60 days. In addition, the microstructural evaluation, initial surface absorption test, = environmental impact, and cost-benefit analysis were evaluated. The results show that the incorporation of RHA reduces the workability of fresh mixes, while enhancing their compressive, splitting, and flexural strength up to 7.16%, 7.03%, and 3.82%, respectively. Moreover, incorporating 10% of RHA provides the highest compressive strength, splitting tensile, and flexural strength, with an improved initial surface absorption and microstructural evaluation and greater eco-strength efficiencies. Finally, a relatively lower CO -eq (equivalent to kg CO ) per MPa for RHA concrete indicates the significant positive impact due to the reduced Global Warming Potential (GWP). Thus, the current findings demonstrated that RHA can be used in the concrete industry as a possible revenue source for developing sustainable concretes with high performance.

The concrete industry has long been adding discrete fibers to cementitious materials to compensate for their (relatively) low tensile strengths and control possible cracks. Extensive past studies have identified effective strategies to mix and utilize the discrete fibers, but as the fiber material properties advance, so do the properties of the cementitious composites made with them. Thus, it is critical to have a state-of-the-art understanding of not only the effects of individual fiber types on various properties of concrete, but also how those properties are influenced by changing the fiber type. For this purpose, the current study provides a detailed review of the relevant literature pertaining to different fiber types considered for fiber-reinforced concrete (FRC) applications with a focus on their capabilities, limitations, common uses, and most recent advances. To achieve this goal, the main fiber properties that are influential on the characteristics of cementitious composites in the fresh and hardened states are first investigated. The study is then extended to the stability of the identified fibers in alkaline environments and how they bond with cementitious matrices. The effects of fiber type on the workability, pre- and post-peak mechanical properties, shrinkage, and extreme temperature resistance of the FRC are explored as well. In offering holistic comparisons, the outcome of this study provides a comprehensive guide to properly choose and utilize the benefits of fibers in concrete, facilitating an informed design of various FRC products.

Steel slag is an industrial by-product of steel production which is obtained during the pyrometallurgical process. Technological dissemination on effective utilization of steel slag in vast quantities globally is essential as the generation of steel is escalating year by year and the availability of steel slag is also in millions of tons. Though steel slag has been used for various applications, large quantities of steel slag have been utilized in the field of construction only. This review focuses on the recent advances on utilization of steel slag in construction sector and the impact of steel slag incorporation has been described in detail. Utilization of steel slag in construction industry as aggregate and cementitious material for the applications toward bricks production, asphalt mixes, radiation shielding concrete, foam concrete, self-compacting concrete, ceramic manufacturing, waterproof mortars and geopolymer composites fabrication has been discussed in detail. Steel slag will be an alternate source to conserve natural resources by utilizing large quantity of steel slag in construction industry.

Earnings management is the practice of deriving certain benefits by intervening in external financial reporting or misleading certain stakeholders through adjustments to accruals without cash flow involvement or with affecting cash flows through real activities. Using the models of Kothari et al. (2005) and Cohen et al. (2008) for accrual-based earnings management (AEM) and real activities earnings management (REM), respectively, we examined whether relationships exist between key financial indicators, such as cash flows from operations, operating income, and debt dependency level, and AEM and REM in the ready mixed concrete (RMC) industry in Korea. This study is the first to investigate earnings management in Korea’s RMC sector. Results showed that operating income and cash flows from operations are significantly negatively related to AEM and REM, consistent with the findings of previous research. By contrast, debt dependency exhibits no significant relationship with AEM and REM, contradicting the findings of most previous studies. As a moderating variable, operating income affects the relationship between cash flows from operations and earnings management with only REM. On these bases, we can infer that earnings management in the Korean RMC industry responds differently to key financial indicators with regards to AEM and REM practice. Overall, companies in the industry implement aggressive earnings management depending on operating income and cash generation ability level rather than debt dependency level. These findings provide important insights for people who are interested in accounting information on the RMC industry in Korea.

Siliceous fly ash (FA) is the main additive to currently produced concretes. The utilization of this industrial waste carries an evident pro-ecological factor. In addition, such actions have a positive effect on the structure and mechanical parameters of mature concrete. Unfortunately, the problem of using FA as a Portland cement replacement is that it significantly reduces the performance of concretes in the early stages of their curing. This limits the possibility of using this type of concrete, e.g., in prefabrication, where it is required to obtain high-strength composites after short periods of curing. In order to minimize these negative effects, this research was undertaken to increase the early strength of concretes with FA through the application of a specifically formulated chemical nano-admixture (NA) in the form of seeds of the C-S-H phase. The NA was used to accelerate the strength growth in concretes. Therefore, this paper presents results of tests of modified concretes both with the addition of FA and with innovative NA. The analyses were carried out based on the results of the macroscopic and microstructural tests in five time periods, i.e., after 4, 8, 12, 24 and 72 h. The results of tests carried out with the use of NA clearly indicate the possibility of using FA in a wide range of management areas in sustainable concrete prefabrication.

PURPOSE: The concrete industry faces challenges to create concrete mix designs that reduce negative environmental impacts but also maintain high performance. This has led to ‘greener’ cementitious materials being developed which can decrease the use of traditional Portland cement (PC). This study intended to carry out a ‘cradle-to-gate’ life cycle assessment (LCA) on concrete mix designs containing different cementitious blends. METHODS: The aim of this study was to obtain the overall environmental impact, with a particular focus on carbon dioxide (CO₂) emissions of three concrete mix designs: CEM I (100 % PC content), CEM II/B-V (65 % PC content, 35 % Fly Ash (FA) content) and CEM III/B (30 % PC content, 70 % ground granulated blast furnace slag (GGBS) content). Evaluations of the three concrete mixes were performed using ‘SimaPro 8’ LCA software. A comparative cradle-to-gate LCA of these mixes has not currently been explored and could present a new insight into improving the environmental impact of concrete with the use of secondary materials. Recommendations from this work would help the industry make key decisions about concrete mix designs. RESULTS AND DISCUSSION: Results show that Mix 2 (CEM II/B-V) and Mix 3 (CEM III/B) could potentially be taken forwards to improve their environmental impacts of concrete production. With respect to optimum mix design, it is strongly recommended that GGBS is selected as the addition of choice for reducing CO₂ emissions. FA does still considerably improve sustainability when compared to PC, but this work proved that inclusion of GGBS environmentally optimises the mix design even further. Advantages of using GGBS include lower CO₂ emissions, a substantial reduction of environmental impacts and an increased scope for sustainability due to the higher PC replacement levels that are permitted for GGBS. Due to mix designs enabling a higher contribution of GGBS additions, it would also indicate an increased positive effect regarding waste scenarios. CONCLUSIONS AND RECOMMENDATIONS: The main contribution of this work demonstrated that concrete can be produced without loss of performance whilst significantly reducing the negative environmental impacts incurred in its production. The results obtained from this work would help to define the available options for optimising concrete mix design. The only material variations in each mix were the different cementitious blends. So, by determining the best option, a platform to make recommendations can be established based upon cementitious materials.