Effect of filler-resin ratio on the physical, mechanical and durability properties of heavy aggregate-based polymer composites

In this study, the effect of resin-filler ratio on the physical, mechanical and durability properties of polymer composites was investigated. Iron-manganese (IM) aggregate was used as filling material. Within the study, polymer composite samples were produced using six different resin-filler ratios (15–85%, 20–80%, 25–75%, 30–70%, 35–65% and 40–60%). The specimens were examined and tested for apparent density, water absorption, porosity, ultrasonic pulse velocity (UPV), compressive strength, flexural strength, freeze-thaw (FT) cycles and compressive strength after sulphate impact. The results obtained showed that the resin-fill ratio had a significant effect on the homogeneous distribution of aggregates. While structural integrity could not be achieved when the resin content was below 15%, significant segregation problems occurred when the resin content was above 40%. It was also determined that the increase in resin ratio led to a decrease in apparent density, water absorption and porosity values, while increasing UPV, compressive strength, flexural strength and durability properties. Additionally, FTIR analysis revealed similar vibration peaks across all composite samples. In the P35IM65 and P40IM60 samples, the increased polyester content filled the gaps between the IM aggregates, resulting in a more cohesive matrix-aggregate interface. Optimizing the resin/filler ratio is a complex process that requires a careful balance to meet the varying requirements for mechanical properties, durability and structural integrity. In this study, the optimal resin-filler ratio for ensuring the structural integrity of the aggregates was determined to be 15:85, while the most effective ratio for enhancing mechanical properties and durability was found to be 40:60.

Graphical abstract