The incorporation of recycled aggregate (RA) from the construction and demolition waste (C&DW) in civil engineering applications has become a hot research topic worldwide due to the associated environmental benefits of its application. Nonetheless, the poor quality of RA reduced its attraction to be utilized widely in the construction industry. This research examined the effects of soaking RA in cement-pulverized fuel ash-silica fume method (SCP), sand envelope mixing approach (SE), and bi-combination of SCP + SE on the water absorption, resistance to freeze–thaw, and sulphate resistance of recycled aggregate concrete (RAC). This study also investigated the microstructure of the enhanced RACs using scan electron microscopy (SEM) images to validate the experimental results. In addition, a detailed cost analysis of the different enhancement methods utilized in this study was carried out. The enhanced RACs demonstrated improved durability performance which was confirmed by the SEM images. This was ascribed to the strengthened interfacial transition zone, strengthened adhered mortar, better overall interlocking of the treated RA with the new cement paste, filled-up pores and micro-cracks, reduced porosity, and compacted denser microstructure. The outcome of this study would be in a great benefit to researchers, RA producers, design engineers, and stockholders to get a better knowledge on the durability property of RAC produced with 100 % treated RA, and thus promote the use of RA in the construction industry.
|Number of pages||14|
|Journal||Construction and Building Materials|
|Publication status||Published - 12 Sep 2022|
- Recycled aggregate
- Sulphate attack
- Scanning electron microscopy (SEM)
- Cost analysis