Acrylamide in-situ polymerization of toughened sulphoaluminate cement-based grouting materials

• Acrylamide monomer changes the rigid structure of SCGM. • A new PAM-AFt flexible-rigid double network structure is formed. • A new model of axial compressive stress–strain curves for PAM-SCGM is established. In this study, the toughening effect of acrylamide monomer (AM) on sulphate aluminate grouting material (SCGM) is investigated by axial compression, FT-IR, TGA and SEM. The results show that the toughness index ( R ) of acrylamide in-situ polymerization modified sulphoaluminate cement-based grouting material (PAM-SCGM) is 20.56 times than that of the cement paste, due to the in-situ polymerisation of acrylamide monomer forming an organic–inorganic double network structure with cement hydrides. Additionally, a new model of axial compressive stress–strain curves for PAM-SCGM is built, including Zone I (elastic stage), Zone II (yield softening stage), Zone III (plastic stage) and Zone IV (strengthening stage).