Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete

Abstract The aim of this research is to propose a novel technique to improve the performance of structural concrete member using recycled aggregate by creating a core–shell hybrid concrete instead of intermixing natural aggregate concrete with recycled aggregate concrete. The technique involves laye...

Full description

Saved in:
Bibliographic Details
Main Authors: Ji-Hyun Kim, Andres Salas-Montoya, Young-Chan Kim, Chul-Woo Chung
Format: Article
Language:English
Published: SpringerOpen 2025-07-01
Series:International Journal of Concrete Structures and Materials
Subjects:
Online Access:https://doi.org/10.1186/s40069-025-00790-4
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849334856277819392
author Ji-Hyun Kim
Andres Salas-Montoya
Young-Chan Kim
Chul-Woo Chung
author_facet Ji-Hyun Kim
Andres Salas-Montoya
Young-Chan Kim
Chul-Woo Chung
author_sort Ji-Hyun Kim
collection DOAJ
description Abstract The aim of this research is to propose a novel technique to improve the performance of structural concrete member using recycled aggregate by creating a core–shell hybrid concrete instead of intermixing natural aggregate concrete with recycled aggregate concrete. The technique involves layered casting of a recycled aggregate concrete with natural aggregate concrete, either as a core or as a shell, to prove whether this core–shell hybridization approach has a potential to facilitate the utilization of recycled aggregate for structural concrete. Various core–shell combinations were made using w/c 0.3 and 0.5 concretes, and compressive strength, elastic modulus, and chloride ion diffusivity of the hybrid specimens were measured. This paper also investigated the effects of two-stage mixing approach on properties of recycled aggregate concrete and hybrid concrete. It was found that placing stronger NAC at the outer shell provided higher compressive strength and elastic modulus of core–shell hybrid concrete. Placing NAC at the outer shell also provided lower chloride ion diffusivity as it acted as a diffusion barrier. It is recommended to place a stronger and more durable natural aggregate concrete in the shell to have better mechanical properties and durability. A synergetic effect of hybridization was observed from elastic modulus, not from the compressive strength. It was also found that compressive strength and elastic modulus of core–shell hybrid concrete were successfully estimated using those of control concrete specimens.
format Article
id doaj-art-a38cc4de07f2475bb5ea4cf788c68ed8
institution Kabale University
issn 2234-1315
language English
publishDate 2025-07-01
publisher SpringerOpen
record_format Article
series International Journal of Concrete Structures and Materials
spelling doaj-art-a38cc4de07f2475bb5ea4cf788c68ed82025-08-20T03:45:27ZengSpringerOpenInternational Journal of Concrete Structures and Materials2234-13152025-07-0119111810.1186/s40069-025-00790-4Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate ConcreteJi-Hyun Kim0Andres Salas-Montoya1Young-Chan Kim2Chul-Woo Chung3Division of Architectural and Fire Protection Engineering, Pukyong National UniversityDepartment of Civil Engineering, Universidad Nacional de ColombiaDivision of Architectural and Fire Protection Engineering, Pukyong National UniversityDivision of Architectural and Fire Protection Engineering, Pukyong National UniversityAbstract The aim of this research is to propose a novel technique to improve the performance of structural concrete member using recycled aggregate by creating a core–shell hybrid concrete instead of intermixing natural aggregate concrete with recycled aggregate concrete. The technique involves layered casting of a recycled aggregate concrete with natural aggregate concrete, either as a core or as a shell, to prove whether this core–shell hybridization approach has a potential to facilitate the utilization of recycled aggregate for structural concrete. Various core–shell combinations were made using w/c 0.3 and 0.5 concretes, and compressive strength, elastic modulus, and chloride ion diffusivity of the hybrid specimens were measured. This paper also investigated the effects of two-stage mixing approach on properties of recycled aggregate concrete and hybrid concrete. It was found that placing stronger NAC at the outer shell provided higher compressive strength and elastic modulus of core–shell hybrid concrete. Placing NAC at the outer shell also provided lower chloride ion diffusivity as it acted as a diffusion barrier. It is recommended to place a stronger and more durable natural aggregate concrete in the shell to have better mechanical properties and durability. A synergetic effect of hybridization was observed from elastic modulus, not from the compressive strength. It was also found that compressive strength and elastic modulus of core–shell hybrid concrete were successfully estimated using those of control concrete specimens.https://doi.org/10.1186/s40069-025-00790-4Recycled aggregateLayered castingTwo-stage mixingCompressive strengthElastic modulusCore–shell hybrid
spellingShingle Ji-Hyun Kim
Andres Salas-Montoya
Young-Chan Kim
Chul-Woo Chung
Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
International Journal of Concrete Structures and Materials
Recycled aggregate
Layered casting
Two-stage mixing
Compressive strength
Elastic modulus
Core–shell hybrid
title Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
title_full Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
title_fullStr Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
title_full_unstemmed Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
title_short Applicability of Core–Shell Hybridization Approach Using Natural and Recycled Aggregate Concrete
title_sort applicability of core shell hybridization approach using natural and recycled aggregate concrete
topic Recycled aggregate
Layered casting
Two-stage mixing
Compressive strength
Elastic modulus
Core–shell hybrid
url https://doi.org/10.1186/s40069-025-00790-4
work_keys_str_mv AT jihyunkim applicabilityofcoreshellhybridizationapproachusingnaturalandrecycledaggregateconcrete
AT andressalasmontoya applicabilityofcoreshellhybridizationapproachusingnaturalandrecycledaggregateconcrete
AT youngchankim applicabilityofcoreshellhybridizationapproachusingnaturalandrecycledaggregateconcrete
AT chulwoochung applicabilityofcoreshellhybridizationapproachusingnaturalandrecycledaggregateconcrete