Relationship between the bonding strength of epoxy resin and concrete under different conditions

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This post was last edited by Wang Wei2 on 2024-3-4 07:47. The relationship between the bonding strength of epoxy resins and concrete under different conditions was studied. Systematic comparative tests were conducted on the bonding strength between mortar and concrete under various factors; the bonding strength varies depending on the condition of the concrete surface, and roughening the concrete surface can enhance this bonding strength. Concrete with different surface treatments was bonded using an epoxy mortar with a ratio of epoxy resin to filler of 1:2.5, and the bond shear strength after 28 days was measured. The results were as follows: untextured surface – 7.2 Mpa; textured with coarse sandpaper – 15.4 Mpa; textured with coarse sandpaper and polished with fine sandpaper – 8.4 Mpa; soaked in 5% hydrochloric acid for 15 minutes, then washed and dried – 12.0 Mpa. The higher the moisture content of the concrete, the lower its bond strength. The 28-day bond shear strength of concrete with different moisture contents was measured, with the following results: moisture content of 0% resulting in 11.04 Mpa; moisture content of 5.15% giving 4.37 Mpa; and moisture content of 7.04% yielding 2.91 Mpa. The higher the consistency of the epoxy mortar, the lower its bond strength. The flexural bond strength between different densities of epoxy mortar and concrete was measured, with the following results: when the amount of filler was 0.5 times that of the epoxy resin, the density was 6.8 cm and the bond strength was 9.795 Mpa; when the filler amount was 2.5 times that of the epoxy resin, the density was 4.9 cm and the bond strength was 9.750 Mpa; when the filler amount was 4.0 times that of the epoxy resin, the density was 3.8 cm and the bond strength was 9.685 Mpa; and when the filler amount was 6.0 times that of the epoxy resin, the density was 2.4 cm and the bond strength was 7.956 Mpa. Within the temperature range of 0°C to 50°C, a higher curing temperature leads to an increased bond strength. After curing at different temperatures for 7 days, the bond flexural strength of epoxy mortar and concrete was measured and compared; the results are as follows: Ambient temperature of 0°C: 6.03 Mpa; Ambient temperature of 10°C: 11.30 Mpa; Ambient temperature of 20°C: 14.24 Mpa; Ambient temperature of 50°C: 15.65 Mpa