Experimental research on alkali-activated slag high temperature resistant inorganic adhesive pasting CFRP sheets on surface of concrete

In consideration the problem that currently the softening point of resin adhesive used in strengthening concrete structure with carbon fiber reinforced polymer(CFRP) sheets is too low, an inorganic adhesive, alkali-activated slag inorganic adhesive(AASIA) was invented, of which strength does not decrease at the temperature of 600°C. Through double-shear test on AASIA pasting CFRP sheets on the surface of concrete, the optimized mix proportion of AASIA was determined. The method and technology to enhance the infiltration were explored. By testing the compressive strength of AASIA after high temperature, the high temperature resistant of AASIA was demonstrated. The process was firstly, preparing AASIA using a water to slag ratio of 42%, and a water glass to slab ratio of 12% under M=1.0; secondly, immersing and pounding CFRP sheets in AASIA 30min; finally, pasting CFRP sheets with AASIA on the surface of concrete. Shear strength in plane of the specimens was about 1.41MPa, and large area of concrete separates at the interface. The results indicate that it is feasible to strengthen concrete structural members with CFRP sheets using AASIA.