The features of agglomerate materials from recycled raw materials for stormwater purification
Herath Mudiyanselage, Panchali (2025)
Diplomityö
2025
School of Energy Systems, Konetekniikka
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20251210116896
https://urn.fi/URN:NBN:fi-fe20251210116896
Tiivistelmä
The construction sector is a major source of waste, with CDW accounting for 1/3 of the total waste in the European Union. Similarly, urbanization and climate change are challenges for managing stormwater runoffs in Northern Europe. This research explores an innovative solution by investigating the feasibility of agglomerate materials produced from recycled CDW as a filter medium in stormwater filtration systems, supporting the circular economy. The main focus of this study is on the mechanical and durability properties of the agglomerates since they are critical for the performance in real-world applications.
The research was conducted with two different CDW samples obtained from two commercial recycling companies, and the samples were denoted as P and K. Laboratory experiments were performed with manufactured concrete specimens to test the compressive strength, cyclic stress (calculated internal structural damage by freeze-thaw slab test), and freeze-thaw durability (with de-icing salt), adhering to the standard protocols.
Both types of agglomerates exhibited adequate properties to utilize as a filter medium. But sample K outperformed sample P, showing excellent properties. Sample K exhibited the highest mean compressive strength of 10.09 MPa with less variability, whereas sample P exhibited 7.43 MPa. In cyclic stress, sample P demonstrated a mean dilation percentage of 0.20% and 0.15%, whereas sample K demonstrated a mean dilation of 0.12% and 0.14% for 7 and 14 cycles, respectively. Lower deviation of the sample K indicated its higher resistance to internal structural damage. In the freeze-thaw durability test, sample K indicated the highest durability with lower surface scaling, with a mean mass loss of 0.382 kg/m² compared to 0.526 kg/m² of sample P. Overall, these findings validate the feasibility of agglomerates and identified sample K as the most suitable material for filter medium.
The research was conducted with two different CDW samples obtained from two commercial recycling companies, and the samples were denoted as P and K. Laboratory experiments were performed with manufactured concrete specimens to test the compressive strength, cyclic stress (calculated internal structural damage by freeze-thaw slab test), and freeze-thaw durability (with de-icing salt), adhering to the standard protocols.
Both types of agglomerates exhibited adequate properties to utilize as a filter medium. But sample K outperformed sample P, showing excellent properties. Sample K exhibited the highest mean compressive strength of 10.09 MPa with less variability, whereas sample P exhibited 7.43 MPa. In cyclic stress, sample P demonstrated a mean dilation percentage of 0.20% and 0.15%, whereas sample K demonstrated a mean dilation of 0.12% and 0.14% for 7 and 14 cycles, respectively. Lower deviation of the sample K indicated its higher resistance to internal structural damage. In the freeze-thaw durability test, sample K indicated the highest durability with lower surface scaling, with a mean mass loss of 0.382 kg/m² compared to 0.526 kg/m² of sample P. Overall, these findings validate the feasibility of agglomerates and identified sample K as the most suitable material for filter medium.