Study on Preparation and Performance of Modified Urea-formaldehyde Resin Grouting Materials

The influence of different curing systems on the properties of urea-formaldehyde(UF) grouting materials were investigated,and prepared modified UF resin grouting materials by using the modifiers of nano-SiO2 sol,water glass and broken basalt fibers.Results showed that,the compound curing system of ammonium chloride and phosphoric acid had better combination properties,curing time was 5.5 min,compressive strength was 4.94 MPa,bond strength was 0.63 MPa.Among the three modifiers,broken basalt fibers had the best combination properties,when filling with 2% fibers,curing time was 6 min,compressive strength was 16.72 MPa,bond strength was 2.54 MPa,which improved 240% and 301% than unmodified UF resin respectively.The grouting tests in the pit of coal mine proved,the modified UF grouting material met the need for grouting in broken coal.