Concrete is a highly prevalent construction material on a global scale, owing to its exceptional mechanical properties, long-lasting nature, and adaptable characteristics. Nevertheless, the manufacturing process of concrete has a substantial ecological influence, due to the considerable energy consumption and the release of greenhouse gases linked to cement manufacturing ^[1][2]. Consequently, there is an increasing scholarly focus on the development of more environmentally friendly variants of concrete, obtained through the integration of byproducts derived from various industrial sectors.

The manufacturing process of cement, a crucial component in the creation of concrete, constitutes a significant contribution to carbon emissions. The production process entails subjecting limestone and other raw materials to elevated temperatures, resulting in the liberation of carbon dioxide (CO₂) as a secondary output ^[3][4]. According to the International Energy Agency, the cement sector is responsible for around 7% of worldwide carbon dioxide (CO₂) emissions ^[5].

In order to mitigate the environmental impacts of concrete, various strategies can be employed. These include utilising alternative materials during cement manufacturing, enhancing the efficiency of cement production processes, minimising the distances travelled during the transportation of raw materials and finished products, and embracing sustainable construction practices that prioritise energy conservation and waste reduction ^[6][7][8].

In essence, sustainable development in the context of concrete pertains to the use of ecologically sound and socially conscientious approaches in the manufacturing and utilisation of concrete. The objective encompasses the mitigation of environmental consequences associated with concrete manufacturing, the optimisation of natural resource utilisation, and the enhancement of social and economic advantages derived from concrete production. The aforementioned objectives can be attained by employing alternative materials, such as recycled aggregates and supplemental cementitious materials, optimising production methods to minimise waste and energy consumption, and designing concrete structures that enhance durability and resilience. The implementation of sustainable developmental practices in the concrete sector is of paramount importance for ensuring the long-term survival of the construction industry and for promoting environmental well-being. With the mounting worldwide call for infrastructure, the concrete sector’s role in leading green construction initiatives and safeguarding Earth’s health grows ever more pivotal.

2. Marble Waste

Khyaliya et al. ^[9] studied the substitution of river sand with marble waste in lean mortar. The experimental results demonstrated that the most favourable results were obtained when including marble debris at a range of 25–50%. This led to a decrease in water requirements and a notable enhancement in strength, with values increasing from 2.84 MPa to 7.04 MPa at a 50% replacement ratio. Additionally, the durability of the material was significantly improved. The marble waste mixture, comprising 25%, demonstrated favourable performance when subjected to sodium sulphate and sulfuric acid exposure. In accordance with the findings of Omer Farroq et al. ^[10], it is evident that marble waste can serve as a feasible alternative to river sand in lean mortar. It is advised that the replacement range for marble waste should fall within the range of 5–15%. The study conducted by Valeria Corinaldesi et al. ^[11] investigated the utilisation of marble powder, a by-product generated during the process of cutting marble, as a potential mineral addition in self-compacting concrete. The powder demonstrated a narrow particle size distribution, with 90% of particles being smaller than 50 μm, 50% of which were smaller than 7 μm. The experiment involved the evaluation of cement pastes that included the addition of marble powder. These pastes were tested in different mortar combinations, specifically those with a sand–cement ratio of 3:1. The findings of the study revealed that replacing 10% of sand with marble powder resulted in the highest compressive strength, while also preserving the workability of the mixture. This level of substitution was shown to be comparable to the reference mixture after a curing period of 28 days. The use of marble powder resulted in enhanced cohesiveness in both mortar and concrete, even when combined with a superplasticising additive. The resulting specified minimal thixotropy values indicated the absence of energy loss during the installation of the concrete. According to the findings of Bhaskar Prakash et al. ^[12], it was observed that the incorporation of additional cement additives, such as silica fume and fly ash, resulted in improved durability performance when mixed with WMP. A scanning electron microscopy (SEM) analysis demonstrated a high degree of compaction in cement composites with lower levels of cement replacement (10%) with waste mineral powder (WMP). Singh et al. ^[13] extensively examined the use of wasted marble powder as a partial replacement for concrete sand and cement. This study explores substitution ratios with marble powder at 10–15%. This addition increases compressive and split tensile strengths by 15–20%. Marble powder can replace 35–50% of sand and improve strength and durability due to better compaction. The cost analysis shows that replacing 15% of cement with marble powder saves 9.077%. Replacing 25% of sand costs 3.27% more. Marble powder in concrete reduces carbon emissions, thus reducing carbon footprints. This approach also reduces energy consumption by 1.05%. Kore et al. ^[14] also stated that marble powder in concrete reduces the environmental impact of cement and sand extraction. Silva et al. ^[15] investigated the effects of different ratios of waste marble fine aggregates on concrete. The researchers conducted an evaluation of the feasibility, compactness, robustness, and resistance to wear of several mixtures, including varying proportions (0%, 20%, 50%, and 100%) of alternative aggregates in place of the primary aggregates. The results indicated a decrease in workability, as well as a decrease in compressive and cracking tensile strengths across all concrete mixtures as the proportion of replacement material rose. Singh et al. ^[16], using regression analysis, concluded that WMP contributes approximately 8% to the total compressive strength of concrete. Choudhary et al. ^[17] discovered that the porosity, interfacial transition zone (ITZ), and unit weight of the self-compacting concrete (SCC) mixtures had significant impacts on the ultrasonic pulse velocity (UPV) and dry material equivalent (DME) values. The utilisation of multiple replacement techniques, namely MSP, FA, and SF, at elevated levels resulted in reductions in both the ultimate pore volume (UPV) and dynamic mechanical energy (DME) values. However, when the combined mixture was analysed, it was found to have the highest UPV value, as well as a DME value that was comparable to the control mixture. The blended mixture exhibited enhanced microstructural properties. The examination conducted using field emission scanning electron microscopy (FESEM) revealed the presence of a reduced number of voids and an enhanced interfacial transition zone (ITZ). Choudhary et al. ^[18] conducted a study with the objective of examining the durability performance of self-compacting high-strength concrete (SCHSC). This was achieved by including silica fume and fly ash as mineral admixtures, as well as waste marble slurry (WMS) as a potential substitute for cement. The durability values of the SCHSC mixtures were assessed using a series of tests, including water permeability, chloride penetration, carbonation, corrosion, and drying shrinkage. The microstructural development of SCHSC mixtures was analysed using X-ray diffraction (XRD) techniques. The findings of the study indicated that the inclusion of mineral additives and waste marble slurry (WMS) resulted in enhanced durability characteristics in the asphalt mixtures. The durability characteristics validate the superior performance of the SCHSC (self-compacting high-strength concrete) including 10% waste marble slurry (WMS), 15% fly ash, and 5% silica fume. Vardhan et al. ^[19] investigated the behaviour of setting, the development of strength, and the microstructural characteristics of cement pastes with marble powder. The incorporation of cement replacement materials at a maximum of 10% preserves the desirable characteristics of the mixture, thus improving its workability while ensuring that its compressive strength remains uncompromised. The expansion and setting characteristics of cement are not affected by variations in the chemical composition between marble powder and cement. Sharma et al. ^[20] found that an excessive amount of replacement leads to delays in the process of hydration and results in the formation of a porous microstructure, which has a detrimental impact on the mechanical characteristics. The study recommends a maximum replacement of 5–10% of cement with marble powder in construction applications. In the study conducted by Reddy et al. ^[21], the feasibility of substituting natural sand with waste marble dust (WMD) in concrete was investigated. The results of their study demonstrated that WMD can be utilised as a viable alternative to fine aggregate in concrete, with a substitution rate of up to 50%, while maintaining the concrete’s strength without any notable drop. It is worth mentioning that a substitution rate of 50% resulted in the attainment of the maximum compressive strength values of 23.91 MPa at the end of a 7-day period, and 35.54 MPa after 28 days, specifically for M25 grade concrete. Once the replacement percentage exceeded 50%, there was a noticeable decrease in compressive strength. The study conducted by Gupta et al. ^[22] showed that the incorporation of a blend of marble cutting waste (MCW) and fly ash (FA) exhibits considerable potential in the development of environmentally sustainable concrete and in mitigating cement usage. In the context of high-strength concrete blends, it is possible to replace a portion of the overall cement content, specifically up to 10%, with a material known as MCW. This substitution has been seen to yield enhancements in the fresh, mechanical, and durability characteristics of the concrete. The inclusion of 15% fly ash as a replacement for cement did not exhibit any detrimental consequences. The utilisation of a combination of 15% fine aggregate and 10% medium-coarse aggregate demonstrated improved performance, resulting in the production of high-strength concrete that is both cost-effective and long-lasting. Furthermore, the study conducted by Ahmadi et al. ^[23] revealed that the substitution of fine aggregate with marble waste resulted in a greater compressive strength compared to the control sample. The incorporation of steel fibres at a concentration of 0.5% resulted in enhancements to the microstructure of the cement paste, leading to an increase in compressive strength. The act of increasing the fibre count and substituting marble aggregate resulted in an elevation of the bending strength. The performance of mixtures incorporating both steel fibres and marble debris exhibited superior results compared to mixtures including only steel fibre. As the percentage of recycled aggregates and the dose of steel fibres increased, there was a corresponding drop in the rate of water absorption.

3. Fly Ash

Khankhaje et al. ^[24] reviewed several previous studies and observed that the incorporation of fly ash into Portland cement resulted in a decrease in void content and permeability. This phenomenon was attributed to the filler effect exhibited by fly ash. The study determined that the most effective level of cement substitution with FA ranged from 10% to 30%. Nevertheless, elevated replacement levels had an adverse effect on hydration, resulting in a decline in strength. The incorporation of fine aggregates into Portland cement resulted in improved resistance to abrasion and decreased drying shrinkage as compared to conventional Portland cement. In summary, the utilisation of fly ash as a partial substitute for cement presents an environmentally benign approach that contributes to the promotion of a more sustainable form of Portland cement. Anish et al. ^[25] studied the utilisation of fly ash and silica fume in concrete. The strength increases in the concrete types were analysed over a curing period of up to 56 days, both with and without the presence of a superplasticiser. The research encompassed the substitution of 50% of cement with fly ash and 20% of fly ash with silica fume in M30 grade concrete. The results of the study provided empirical evidence supporting the efficacy of augmenting cement concrete with the incorporation of fly ash, silica fume, and superplasticiser. Mohana et al. ^[26] revealed that mortars containing 1% nano-fly ash demonstrated superior compressive strength compared to other compositions under various temperature settings. The mortars exhibited a remarkable capacity to maintain 67% of their initial strength following exposure to a peak temperature of 900 °C. This resulted in a notable decrease of 46% in greenhouse gas emissions, as well as a significant reduction of 18.3% in construction expenses pertaining to the implementation of the environmentally friendly mortar. Singhal et al. ^[27] observed that the replacement of 35% of ordinary Portland cement with fly ash resulted in an elevation in the compaction factor and a decrease in the required dosage of admixture. However, the use of MSP as a replacement for fine aggregate resulted in a loss in workability. The integration of MSP and FA as substitutes for fine aggregate and OPC, respectively, has demonstrated enhanced permeability characteristics. Shukla et al. ^[28] emphasised the importance of appropriate curing techniques for concrete under diverse environmental circumstances. The use of fly ash has been found to enhance strength by approximately 30% under typical loads and 20% under more challenging conditions. The material provides enhanced workability, reduced heat release, improved resistance to sulphates, and increased resilience to weather conditions. Fly ash is in accordance with the criteria set by sustainable construction standards and exhibits a wide range of applications. The research conducted in India’s building sector shows encouraging results. Significantly, the utilisation of fly ash contributes to environmental preservation through the mitigation of CO₂ emissions, the regulation of the greenhouse effect, and the mitigation of pollutants.

4. Redefining High-Rise Construction: The Potential of Marble Waste and Fly Ash

The examination of the function of high-rise structures in urban sustainability and energy consumption has been the subject of numerous studies. Saroglou et al. ^[29] emphasised the importance of constructing envelope designs in tall buildings, with a specific focus on the Mediterranean environment. They draw attention to the potential of double-skin façades (DSFs) in enhancing thermal efficiency. According to a comprehensive assessment conducted between 2005 and 2020 ^[30], it has been shown that high-rise structures, despite their space efficiency, tend to demonstrate increased energy consumption and carbon emissions. This conclusion was reiterated in further research ^[31], which examined the energy efficiency of tall office buildings, proposing DSFs as a viable method for achieving a balance between visibility and energy performance. Furthermore, a particular emphasis on the residential domain ^[32] has revealed the energy-conserving capabilities of fibre-reinforced lightweight aggregate concrete (LWAC), which presents significant energy efficiency advantages when compared to conventional building materials. In the context of urban construction dynamics, it is worth noting that a thermodynamic study ^[33] highlighted the significant increase in reinforced concrete high-rise buildings in Asian cities during the post-war period. This surge may be attributed mostly to economic incentives, rather than a focus on long-term structural durability. This development signifies a crucial turning point in the field of urban construction. The carbon dioxide (CO₂) emissions resulting from the manufacture of concrete exhibit a direct correlation with the quantity of cement incorporated into the concrete mixture. For a more tangible perspective, consider that the production of 1 ton of cement results in approximately 0.9 tons of CO₂ emissions ^[34]. By replacing a portion of the cement with fly ash or marble powder, the need for cement is reduced, leading to potential decreases in CO₂ emissions and resulting in potential environmental benefits.