Experimental investigation of long-term filtration properties of recycled concrete material

In this study, the adequacy of concrete material, which is one of the demolition wastes, for use in under-road drainage systems was investigated by experimental methods. The drainage system consisting of recycled concrete aggregate (RCA) obtained by recycling concrete wastes and non-woven geotextile, which improves filtration performance, was developed and manufactured based on the 𝐴𝑆𝑇𝑀 𝐷 5101 (2023) standard to examine the time-dependent filtration performance and clogging status. Long-term filtration (LFT) experiments were carried out in the developed test system. With the LFT experiment, it is expected that the RCA-geotextile system will start to experience clogging due to fine grain material migration caused by water flow. However, it is hypothesized that the clogging will remain within the clogging limits specified in the specifications and therefore RCA can be used instead of natural aggregate (NA). The hydraulic gradient ratio (𝐺𝑅) and permeability ratio (𝐾𝑅) values were determined to examine the clogging performance of the RCA-geotextiles system in the experiments conducted under different hydraulic gradients. In the light of the data obtained from the experiments, it was observed that the performance of RCAs is comparable to that of NA's at an acceptable level and that the use of RCAs can contribute positively to the storage problem of waste materials, reduce environmental damage and contribute to sustainable materials management (𝑆𝑀𝑀).