Experimental Verification of Use of Secondary Raw Materials as Fillers in Epoxy Polymer Concrete

Abstract

Generally, fillers make up more than 70% of the volume in polymer concrete (PC). Silica sand of various fractions with optimal round-shaped grains is one of the most widely used fillers in PC. Silica sand is the primary raw material and its replacement by some progressive secondary raw materials could be appropriate if PC shows the same or better physical and mechanical properties. In this paper, the possibility of using secondary raw materials such as waste container glass (WCG), waste auto glass (WAG), waste foundry sand (WFS), waste slag (WS), and fly ash contaminated by denitrification process (FAD) are examined to see if they can replace the commonly used round-grain pure crystal silica sand (REF) in epoxy PC. Based on the compressive strength and three-point flexural strength test results, the best PC formulations were selected, which were subsequently tested for the pull-off bond strength. Samples with optimum amount of the filler were also monitored for the microstructure using a high-resolution optical microscope. It was found that the most suitable fillers of the secondary raw materials tested were waste foundry sand (WFS) and waste container glass (WCG). It was also determined that the optimal amount of these progressive fillers of suitable granulometry is 75% by weight, when the PC showed the best physical and mechanical parameters. It was confirmed that by replacing the currently used primary natural material, silica sand, with the secondary raw materials, it is possible to achieve better properties of PC and at the same time improve the environmental and economic benefits of PC production.