Pore size distribution and compressive strength of waste clay brick mortar

This paper reports the results of an investigation of the pore size distribution of mortar that contains varying amounts of ground brick from different European brick types. 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 standard mortars. The pore volume, pore size distribution, threshold radius and strength of these mortars were tested for curing periods of up to one year. The presence of ground brick (GB) alters significantly the compressive strength of mortar and this is attributed to both the dilution effect and production of additional C-S-H gel from reaction of GB with CH. The additional C-S-H gel refines the pore size distribution of the mortar and this is reflected in compressive strength values obtained for these mixes. A critical relationship between threshold radius and compressive strength is also observed. (C) 2001 Elsevier Science Ltd. All rights reserved.