Cement stone, modified by galvanic sludge

Abstract

Abstract The relevance of the research topic stems from the use of multi-tonnage industrial waste in cement systems. One such waste is the sludge resulted from electroplating aluminum alloy products. Galvanic (electroplating) sludge is pasty and unstable in moisture. For this purpose, it was previously dried and then grinded so it could be rationally used. Impact of sludge on technological properties of cement stone and strength properties of cement stone were studied according to standard normative methods. It is shown that galvanic sludge increases the water demand of cement paste. Therefore, the joint effect of naphthalene formaldehyde and polyester carboxylate-based sludges with plasticizing added was studied. Their efficiency depends on the way they are produced. The mixed use of galvanic sludge with plasticizing additives reduces the water-cement ratio by 20-40 %, increases the strength of cement stone within the early hardening time by 3 times and in 2 times in the grade age. The phase composition of the modified cement stone was studied using defective thermal analysis. It was established that using galvanic sludge together with plasticizing additives decreases portlandite. The article can be useful for those recycling the waste in question.