A Green Way of Producing High Strength Concrete Utilizing Recycled Concrete

Shaaban, Mostafa; Edris, Walid Fouad; Odah, Essam; Ezz, Mohamed Salah; Al-Sayed, Abd Al-Kader A.

doi:10.28991/cej-2023-09-10-08

Cited by 8 publications

(1 citation statement)

References 48 publications

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“…The utilization of recycled coarse aggregates (RCA) in concrete has undergone extensive research in various countries and has been implemented on a global scale (3). In contemporary society, there is a growing apprehension regarding the escalating magnitude of Construction and Demolition (C&D) substances as well as the significant fraction of refuse amassing in landfills (4). Within the realm of construction, a substantial portion of refuse originates from the demolition of edifices.…”

Section: Introductionmentioning

confidence: 99%

Machine Learning Models for Mechanical and Micro Structural Properties of Recycled Fine Aggregate Concrete Using Different Mixing Approaches

Ranjith,

Yashwanth,

Kiran

et al. 2024

IJE

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The construction industry is primarily responsible for the depletion of natural resources and the disruption of environmental equilibrium due to unregulated mining activities. In this particular context, the utilization of recycled fine aggregate (RFA) derived from construction and demolition (C&D) waste presents itself as a viable solution. The conventional method of mix proportioning for RFA in concrete is not applicable in this case. The main innovation of our research lies in the fulfilment of one of the principles of circular economy, namely the reduction of carbon emissions, through the recycling of locally collected concrete waste. To tackle this issue, a novel triple mix-proportioning approach has been developed using the concepts of maximum packing density and minimum paste theory. The fresh and hardened properties were evaluated and microstructural characterization was carried out for the newly formulated mixes incorporating RFA with optimized combined aggregates. The compressive strength of concrete with recycled fine aggregate increases by 5.04% for 25% and, 21.69% for 50% replacement, and decreases by 35.44% for 100% replacement as compared to controlled concrete at the age of 28 days using the triple mixing approach. The findings indicate that replacing approximately 50% of sand with RFA is the optimal amount, as further replacement leads to a decrease in compressive strength, particularly at 100% replacement due to the presence of adhered mortar in RFA. In this study, the performance evaluation of RFA concrete has been conducted by comparing six established ML regression models and sensitivity analysis was performed to assess the variable's performance.

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Section: Introductionmentioning

confidence: 99%

Machine Learning Models for Mechanical and Micro Structural Properties of Recycled Fine Aggregate Concrete Using Different Mixing Approaches

Ranjith,

Yashwanth,

Kiran

et al. 2024

IJE

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Strength and Durability of Superplasticizer Concrete Based on Different Component Parameters: An Experimental and Statistical Study

Tugrul Tunc

2024

Arab J Sci Eng

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Concrete, which forms the skeleton of buildings, is the most important building material to ensure the continuity of a building’s durability and to survive a possible earthquake. Concrete durability is directly related to its constituent materials. In this study, it was investigated how concrete aggregate and chemical admixture change the strength of concrete according to their type. The research question of this study is: what is the place and importance of aggregate and chemical admixture in increasing concrete strength? Recent earthquakes, especially in Turkey, have shown that most of the buildings that collapsed had poor-quality concrete. The aim of this study is to determine the concrete mix designs for the production of superplasticizer concrete for the production of concrete with the desired strength depending on the tested parameters. In this study, the effect of the parameters that make up the tested concrete content on concrete strength was investigated both experimentally and statistically. Water–cement ratio, aggregate type, Los Angeles abrasion resistance of aggregates, aggregate–cement ratio and new-generation polycarboxylate-supported superplasticizer chemical admixture are the parameters in the concrete content. Statistical analysis was carried out with SPSS, an up-to-date software, using the experimental findings. There was a very good agreement between both measured and predicted values. The equations with a coefficient of determination R2 > 0.96 were derived. The developed statistical method was found to be unique and highly accurate. Thus, it is aimed to provide safe, economical, practical and time-saving pre-mix designs.

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Internal Curing Utilising Recycled Concrete Aggregate: A Sustainable Approach for Improving High-Strength Concrete’s Performance

Whwah,

Mahmmod,

Abdoulhaleem

et al. 2024

Arab J Sci Eng

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High-strength concrete (HSC) makes up the vast majority of materials used in the construction sector due to its exceptional mechanical characteristics and outstanding long-term behaviour. However, in cement-based materials with a low water-to-binder ratio (w/b), excessive autogenous shrinkage has become a prevalent issue. This work suggests the sustainable use of recycled concrete aggregate (RCA) to internally cure HSC in order to reduce autogenous shrinkage during the hydration and curing processes. RCA was employed with various volumetric replacement percentages with natural coarse aggregate as a water storage agent (0%, 8%, 16%, 24%, 32%, 50%, 75%, and 100%) under sealed and unsealed conditions. The efficiency of the adopted materials for internal curing was investigated by determining the autogenous shrinkage in addition to unconfined compressive and flexural strength. The laboratory results reveal that the studied properties significantly improved by incorporating RCA into HSC, and the improvement depends on the substitution rate of the coarse aggregate. A better shrinkage behaviour can be obtained by raising the substitution percentage of coarse aggregate with RCA; in contrast, the strengths decrease with increased RCA. RCA can be utilised as an internal curing material for HSC to alleviate autogenous shrinkage with a percentage of around 40%, with the adopted ambient conditions in the early age of HSC with full replacement of virgin coarse aggregate. It is recommended to use 24% RCA as a substitution for natural coarse aggregate for internal curing to improve the characteristics of HSC and the sustainability advantages and reduce its negative environmental impacts.

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A Green Way of Producing High Strength Concrete Utilizing Recycled Concrete

Cited by 8 publications

References 48 publications

Machine Learning Models for Mechanical and Micro Structural Properties of Recycled Fine Aggregate Concrete Using Different Mixing Approaches

Machine Learning Models for Mechanical and Micro Structural Properties of Recycled Fine Aggregate Concrete Using Different Mixing Approaches

Strength and Durability of Superplasticizer Concrete Based on Different Component Parameters: An Experimental and Statistical Study

Internal Curing Utilising Recycled Concrete Aggregate: A Sustainable Approach for Improving High-Strength Concrete’s Performance

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