This study systematically investigates modification methods for recycled aggregate, including acid modification, abrasion testing, and triple-mixing improvement. Recycled aggregate from a single source replaced 50% and 100% of natural aggregate in concrete mixes, which were compared to controls using natural aggregate and unmodified recycled aggregate. Simultaneously, recycled aggregate and recycled waste tire steel fibers were employed to enhance sustainability. Modification effects on properties were isolated by adjusting aggregate gradations and using superplasticizer to control water-binder ratios. Key quantitative findings include a 10% reduction in compressive strength with 50% recycled aggregate and a 15.7% reduction with 100%, due to lower density, increased porosity, and cracks. Modification methods improved strength by 4–9.5% for 50% recycled aggregate and 2–5% for 100% replacement. The triple-mixing method notably enhanced 50% recycled concrete, while acid modification was most effective for 100% recycled concrete. Unit weight decreased by 5% with 50% and 3.6% with 100% recycled aggregate. Workability reduction was observed with recycled fiber addition, while modified recycled aggregate mitigated this effect. Axial stiffness decreased by 21.76% with 100% recycled aggregate, with modification methods showing varied effects. Energy absorption decreased by 19.5% with 50% and 24.3% with 100% recycled aggregate, minimally impacted by modification.
A Comparative Evaluation of Modification Methods for Improving the Mechanical Properties of Recycled Aggregate-Recycled Steel Fiber Concrete
KSCE J Civ Eng
KSCE Journal of Civil Engineering ; 28 , 9 ; 3962-3975
2024-09-01
14 pages
Article (Journal)
Electronic Resource
English
Evaluation of Recementation Reactivity of Recycled Concrete Aggregate Fines
Transportation Research Record | 2014
|Evaluation of Recementation Reactivity of Recycled Concrete Aggregate Fines
Online Contents | 2014
|Fabricated recycled aggregate lightweight concrete prefabricated stair
European Patent Office | 2023
|Recycled Concrete Aggregate Coefficient of Thermal Expansion
Transportation Research Record | 2009
|Structural Lightweight Concrete Containing Recycled Lightweight Concrete Aggregate
Springer Verlag | 2017
|