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Abstract This paper presents an innovative method for the production of masonry bricks, which combines earth compaction and quick firing at low temperatures. Earth bricks were manufactured according to three different methods, i.e. extrusion, standard Proctor compaction and hypercompaction to 100 MPa. All bricks were fired inside an electrical furnace by rising the temperature at a quick rate of about 9 °C per minute to 280, 455, 640, 825 and 1000 °C, after which the furnace was turned off and left to cool to the atmosphere with the brick inside it. These firing temperatures and times are significantly lower than those employed for the manufacture of commercial bricks, which are typically exposed to a maximum of 1100 °C for at least 10 h (Brick Industry Association, 2006). A testing campaign was performed to investigate the effect of quick firing on the porosity, strength, water durability and moisture buffering capacity of the different bricks. Quick firing of hypercompacted bricks at moderate temperatures, between 455 and 640 °C, is enough to attain very high levels of compressive strength, between 29 and 34 MPa, with a good to excellent moisture buffering capacity. These properties are better than those of commercially available bricks. The strength of hypercompacted bricks further increases to 53 MPa, a value similar to that of high-strength concrete, after quick firing at 825 °C. Earth densification prior to thermal treatment therefore improves material performance while enabling a significant reduction of firing temperatures and times compared to current bricks production methods. Highlights • Proctor compacted, hypercompacted and extruded earth bricks were manufactured. • Earth bricks were fired at five temperatures: 280, 455, 640, 825 and 1000 °C. • Thermal treatment was quick to save energy and time. • Compressive strength, water durability and moisture buffering were investigated. • Excellent properties were achieved for hypercompacted bricks with low firing times and temperatures. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of stabilisation by alkaline activation and silicon based admixture on the mechanical properties, moisture buffering capacity and durability of an earthen material for building construction. The stiffness and strength of both unstabilised and stabilised cylindrical samples were measured, under different humidity conditions, by means of unconfined compression tests. The effect of stabilisation on moisture buffering capacity was instead explored by subjecting samples to cyclic variations of relative humidity at constant temperature, according to the experimental procedures prescribed by the norm ISO 24353 [21]. Finally, durability against water erosion was assessed by performing immersion, suction and liquid contact tests on both unstabilised and stabilised samples according to the norm DIN 18945 [16]. Results from this extensive experimental campaign highlighted that the chosen stabilisation methods improved the durability of the material while maintaining a relatively good mechanical performance and a good to excellent moisture buffering capacity. [ABSTRACT FROM AUTHOR]