CORROSION RESISTANCE OF ALKALI ACTIVATED ALUMINOSILICATE MATERIALS

This paper describes a study of impact of various environments on the corrosion resistance of hard-set mortar made of fine ground granulated blast furnace slag, modified water glass with a silicate modulus of M_s = 1.3 and pure silica sand. Having kept samples for 28 days in moist environment, they were exposed to relevant environments for 112 days. Corrosion resistance was determined in solutions of hydrochloric acid, sodium sulphate, magnesium nitrate, or ammonium chloride. Reference samples were kept for the identical period of time in distilled water and air environment. The samples were measured for ultrasonic propagation velocity at 14day intervals, for bending and compression strength at 28day intervals. As a result of the ultrasonic measurements, the modulus of elasticity was calculated. Samples kept in corrosive environments, were studied for their microstructure using a scanning electron microscope. The SEM pictures exhibit various gel-characteristics corresponding to the different mechanical properties and behaviour in the corrosive environments as compared with the Portland cement based products. The mechanical tests have proven the exceptional stability of alkali-activated aluminosilicate materials because exposure to corrosive environment can even slightly increase strengths.

• INTRODUCTION

• COMPOSITION OF COMPOSITES AND BASIC PROPERTIES

• EXPERIMENTAL RESULTS AND DISCUSSION

• CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES