Multi-analytical assessment of ethyl silicate-treated bricks: from salt deterioration to long-term protection

Abstract

This study investigates the effectiveness of ethyl silicate in enhancing the durability of extruded bricks subjected to weathering used by sodium sulphate. Four groups of samples were analyzed and compared: unaltered bricks (F1), salt-weathered bricks (F2), consolidated salt-weathered bricks (F3), and re-weathered consolidated bricks (F4). Chemical and mineralogical changes were evaluated using X-ray fluorescence, Fourier-transform infrared spectroscopy, μRaman spectroscopy, and powder X-ray diffraction. Hydric tests and ultrasound measurements assessed changes in the pore structure and mechanical properties. Colour measurements quantified aesthetic alterations. Mechanical tests evaluated strength, hardness and fatigue resistance. A computational model was also developed to predict long-term behaviour. Results indicate that ethyl silicate treatment significantly enhances weathered brick durability, with consolidated saltweathered samples showing improved mechanical properties and reduced salt damage. However, the re-weathering process revealed some limitations in providing long-term protection. This research offers novelty insights into ethyl silicate consolidation for preserving bricks under conditions of salt weathering.