Journal of Structural and Construction Engineering

Journal of Structural and Construction Engineering

Study of Some Corrosion-Related Durability Properties in Mortars Containing Natural and Recycled Aggregates with Constant Fineness Modulus

Document Type : Original Article

Authors
1 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran
2 Master's student, Department of Civil Engineering, Faculity of Engineering, Bu-Ali Sina University, Hamedan, Iran
Abstract
Recycled aggregates possess weaker properties—like higher water absorption, increased porosity, and lower density—compared to their natural counterparts. Consequently, concretes produced with these recycled materials exhibit inferior mechanical and durability characteristics than natural concretes. Moreover, rebar corrosion poses a significant threat to reinforced concrete structures. Given the reduced durability of recycled concretes, it becomes crucial to investigate corrosion within this specific type of concrete. The current study presented laboratory findings on how recycled aggregates affect the strength and durability of cement-based products, particularly their resistance to rebar corrosion. To achieve this, four different mix designs were prepared, incorporating 0%, 50%, 75%, and 100% recycled aggregates. These mixes featured a maximum nominal size of 2.36 mm and a water-to-cement ratio of 0.6. Subsequently, tests for compressive strength, capillary water absorption, volumetric water absorption, and half-cell potential were conducted. Upon analyzing the results, it was determined that, at a consistent water-to-cement ratio, the inclusion of recycled aggregates led to a decrease in compressive strength and an increase in both capillary and volumetric water absorption. Interestingly, the mix containing 50% recycled aggregate performed quite similarly to the control mixture (which comprised 100% natural materials). Furthermore, half-cell potential test results indicated that recycled aggregates reduce the half-cell potential. This finding were suggested that due to the inherent porosity of recycled aggregates, the protective layer on the rebar deteriorates more quickly, thereby initiating the corrosion process sooner.
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  • Receive Date 06 April 2025
  • Revise Date 07 September 2025
  • Accept Date 27 September 2025