Effect of polyacrylic resin on mechanical properties of granulated blast furnace slag based geopolymer

The mechanical performances of alkali-activated granulated blast furnace slag (GBFS) based geopolymer modified with polyacrylic resin were investigated in this paper. The water-to-binder ratio, alkaline activator content (Na2O wt%) and SiO2/Na2O molar ratio in this experiment maintained at 0.5, 6% and 0.8, respectively. Geopolymer samples were synthesized by alkaline solution and GBFS with incorporating amount of 0.25, 0.5, 0.75, 1.0, 3.0 and 5.0 wt% polyacrylic resin. The mechanical properties of samples were measured using compression tests, flexure tests and bending toughness tests. The results show that the compressive and flexural strength were both up to the maximum value while doping 1 wt% polyacrylic resin, the ratio of flexural-compressive strength and bending toughness at curing 28 days were increased by 36.3% and 104.6% respectively, compared with the control samples. The structural evolutions of specimen after incorporating polyacrylic resin were characterised by FTIR as well as Si-29 NMR spectroscopy. It indicated that a new absorption peak namely Si-O-C bond at wavenumber of about 1180 cm(-1) in the FAIR spectra appeared while incorporating polyacrylic resin whatever 1 wt% or 5 wt%, the chemical shifts corresponding resonance peaks of siliceous species moved towards to low field, and the polymerization degree of Si transformed from Q(3), Q(4) to Q(0), Q(1), Q(2).