Possibilities of Using Hazardous Waste as Filler to Polymer Mortar

Abstract

The aim of the research was to verify whether it is possible to use specific types of treated hazardous waste as a filler in special epoxy based polymer mortars. In particular, it was a neutralizing sludge (NS-HW) with a relatively high content of heavy metals and other hazardous substances. This alkaline sludge is formed as a by-product of galvanic plating of steel elements in the baths, which are subsequently thickened and neutralized with calcium hydroxide. During the experimental verification, it was determined what resulting mechanical properties can be achieved by using 40% of the treated neutralizing sludge as a filler. In order to compare the achieved properties, a reference filler in form of a silica flour was used in the same binding matrix, and the polymer mortar containing waste foam glass of approximately the same fraction. It was discovered that, at the same percent filling, the polymer mortar with neutralizing sludge (NS-HW) had a similar tensile strength similar and cohesion with the concrete substrate as the reference material with the silica flour. Furthermore, it has been shown that this filler lowering the environmental footprint does not affect the chemical resistance of the polymer mortar to aggressive liquid solutions. As part of the microstructure observing, the uniformity of the filler distribution in the hardened polymer mortar, the incorporation of sludge particles into the epoxy matrix, and the quality of the polymer mortar bonding to the concrete was monitored using a high resolution digital microscope.