Document Type : Research Paper
Authors
1
Associate professor, Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
2
Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
10.22124/jcr.2022.19278.1491
Abstract
This experimental research has investigated in particular the durability of fully recycled concrete containing natural zeolite (NZ), microsilica (SF) and fly ash (FA) pozzolans. Recycled concretes consist of recycled concrete aggregates and contain different percentages of replacement of SF, FA and NZ. A total of 11 mixing designs were constructed, including plain reference concrete (RC), 100% recycled concrete without pozzolans, and 9 mixing designs of fully recycled concretes containing the mentioned pozzolanic materials as separate applications. To evaluate and compare some mechanical properties and especially properties related to the durability of this type of concrete, in the age range of 28- to 91-day, compressive strength (CS), in the age range of 28-day the ultr-pulse velocity, and in the age range of 180-day immersion water absorption, capillary water absorption, electrical resistivity and electrical conductivity of specimens made of this type of concretes, were measured. The results showed that although the complete replacement of recycled aggregates in this type of concrete leads to a decrease in their CS compared to the RC, but the replacement of pozzolanic materials such as SF in fully recycled concrete can lead to gain more CS than RC. Also, the rate of loss of durability properties in fully recycled concretes without pozzolans is much higher than the loss of mechanical properties compared to the RC. However, due to changes in the chemical structure of recycled concretes from pozzolanic materials such as NZ, some of the durability properties of these concretes did not change significantly compared to RC.
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