EFFECTS OF ELEVATED TEMPERATURE AND RE-CURING ON THE PROPERTIES OF MORTARS CONTAINING INDUSTRIAL WASTE MATERIALS

Behavior  of  mortars  with  and  without  silica  fume  (SF),  containing  green  ceramic powder  (GCP)  and  marble  dust  (MD)  under  the  conditions  of  pre-fire  and  post-fire  was investigated. In addition, influence of re-curing on the mechanical properties and permeability of fire-damaged  high-strength  mortars  was  studied.  For  this  purpose,  mortars  subjected  to  800 o C were water-cured for 7 days after air-cooling. In order to determine the physical, mechanical and permeability  properties  of  mortars,  the  bulk  density,  water  absorption,  porosity,  flexural  and compressive  strength, capillary  water  absorption  tests  were  conducted  and optical  microscope analyses  were  also  performed. Results  showed  that  mortars  with  MD  had  the  highest  strength values  and  the  lowest  permeability  for  normal  and  post-fire  conditions,  however,  mortars  with GCP showed the best performance among other mortars after re-curing. This can be attributed to the siliceous composition of GCP regarding the vulnerability at high temperature and suitability in C-S-H  re-formation  when  re-curing.  Water-curing  contributed  to  re-hydration  and  self  healing, resulting  in  strength  re-gain  and  porosity  recovery  which  was  also  observed  by  microstructural evaluation.