Sorptivity and Water Absorption of Mortars Incorporating Waste Clay Brick

摘要

This paper reports the results of an investigation of the sorptivity of mortar that contains varying amounts of ground brick from different European bricks. Waste clay brick deriving from four European countries was ground to roughly cement fineness and used to partially replace cement in quantities of 0, 10, 20 and 30% in mortars. The sorptivity and water absorption of these mortars were tested for curing periods of up to one year. The presence of ground brick does not have a significant effect on the water absorption of mortar. Sorptivity however, is affected considerably by not only the presence of ground brick but also by brick composition. Initially, the presence of ground brick in mortar increases its sorptivity. As curing periods increase, the sorptivity values for ground brick mortars decrease at a rate that is greater than that seen in mortars whose binder is 100% portland cement. This indicates that the ground brick decreases the capillarity of the mortar and this is attributed to the production of additional C-S-H gel. The additional C-S-H gel, in effect, refines the pore structure of the mortar and this is reflected in the increase in the compressive strength obtained for these mixes.