In the present work, the properties of rubberize cement mortar containingcrumb rubber treated by acidic solution are tested and compared with normal rubberize and normal cement mortar.The rubber, which is treated by different acidic solution such as: (H2SO4, HCl and CH3COOH) is used as a fine aggregate as avolumetric partial
replacement of sand in cement mortar. The percent of replacement ranged from 5 to 30%.Compressive strength, modulus of rupture and modulus of elasticity (static and dynamic) a retested for all mixes. Cubes of cement mortar also tested by ultrasonic pulse velocity (UPV) and hammer tests method to show the effect of treated rubber on the UPV and hammer tests and to demonstrate the possibility of this methods for
estimating the compressive strength of rubberize cement mortar.The results show that the treatment of rubber by acidic solution significantly improves the properties of rubberize cement mortar. Moreover the results show that CH3COOH gives better improvement compared withH2SO4. The treatment of rubber by HCl shows negative
effects on all cement mortar properties.