Sulphate corrosion of cement pastes with a high content of waste marble powder

Abstract

The article focuses on sulphate corrosion of cement pastes with a high content of waste micronized marble powder. Micronized marble powder is used as a substitute for Portland cement CEM I 42.5R. The amount of micronized marble powder used is from 5 to 50 wt. %. The research also tested a reference mixture composed only of Portland cement. The used accelerated sulphate corrosion consists of cyclic saturation and drying with 10% Na2SO4 solution for 56 days. During sulphate corrosion, samples are placed in a controlled environment at 5 ± 1 ◦C and 85 % relative humidity to allow thaumasite to form. During cycling, samples were continuously visually monitored and documented. Subsequently, after 56 days, the samples were destructively tested for compressive strength. The research revealed a negative effect of micronized marble powder on the resistance to sulphate corrosion, where in contrast to the reference mixture the decrease in compressive strength is up to twofold.