用碱激发矿渣耐高温无机胶在混凝土表面粘贴碳纤维布试验研究

针对目前粘贴碳纤维片材加固混凝土结构所用有机胶软化点过低的问题,研发了在600℃下强度不降低的碱激发矿渣无机胶。通过用碱激发矿渣无机胶在混凝土表面粘贴碳纤维布的双剪试验,确定了碱激发矿渣无机胶的最优配合比。探索了改进碱激发矿渣无机胶对碳纤维布浸润性的工艺和方法。通过测试高温后碱激发矿渣无机胶的抗压强度,验证了碱激发矿渣无机胶的耐高温性。试验过程中,先以水为矿渣粉质量的42%,模数M=1.0的水玻璃为矿渣粉质量的12%的比例制备出碱激发矿渣无机胶,再将碳纤维布在该类无机胶中浸泡并杵捣30m in左右,最后用该无机胶在混凝土表面粘贴浸泡后的碳纤维布。这种试件的面内剪切强度可达1.41MPa,破坏时界面混凝土发生大面积剥离。试验结果表明用碱激发矿渣无机胶粘贴碳纤维布加固混凝土结构构件是可行的。

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℃. 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.