Performance of silica fume-calcium hydroxide mixture as a repair material

The aim of this experimental work was to investigate the performance of a special concrete repair material. The use of silica fume (SF)-Ca(OH)2 mixture, with and without cement addition in reinforced mortars has been studied. The examination of the hydration reaction progress by X-Ray Diffraction (XRD), Differential Thermal Analysis-Thermogravimetry (DTA-TG), and Scanning Electron Microscopy (SEM) analysis of SF-Ca(OH)2 mixture with various cement ratios, shows that calcium silicate hydrate is formed in a desired extent. Damaged specimens repaired by the above-mentioned materials also showed low carbonation depth and the lowest corrosion rate, close to of undamaged specimens. This is attributed to the formation of C–S–H compounds at the interface between these mixtures and cement mortar, resulting in the creation of good binding properties of the repair materials.