Acid resistance of polyester-impregnated modified cement mortar

The influence of distilled water and sulphuric acid solutions on the physic omechanical properties of neat and modified cement mortar has been investig ated. The samples were immersed in distilled water, and different concentra tions of sulphuric acid ranged from 5-15% by vol for immersion times from 1 to 120 days. The effect on the loss of weight, compressive strength, appar ent porosity, water absorption, IR, and SEM were studied. The results indic ate that the compressive strength and loss of weight decrease, whereas the apparent porosity and water absorption increase with immersion time and aci d concentration. These are probably due to partial dissolution of the set c ement. IR spectra and SEM studies showed significant changes in some absorp tion bands and the appearances of new voids of the neat and composite morta rs after being immersed in H2SO4 solutions. (C) 1999 John Wiley & Sons, Inc .