Application of a clay-slag geopolymer matrix for repairing damaged concrete: Laboratory and industrial-scale experiments

Abstract

Blast-furnace slag, a remnant of the old iron production, was used for a preparation of a clay-slag geopolymer which was applied to old concrete surface. An interface investigation by scan electron microscopy (SEM) confirmed the hypothesis that a clay-slag geopolymer can be used for repairing concrete. Based on the laboratory experiments, a highly damaged and contaminated old concrete floor with potholes ranging from 2 mm to 20 cm, located in metal manufacturing industrial plant, has been repaired overnight by a clay-slag geopolymer matrix (ratio of 1: 0.5) filled with sand and pebbles (the total content of 70 wt.-%). This industrial-scale experiment has proven that geopolymers are suitable for damaged concrete repair and the daily rush in heavy industrial conditions has confirmed the resistance and surface hardness of the geopolymer mixture used. The article documents the original state of the floor, its state after eight hours and also two and four years later.