The most important research trends that the world is currently interested in are those that have a positive impact on the environment. The burning of the waste tyres is one of the most used means to get rid of these tyres, which causes a lot of gases to the air. The use of crumbed tyre rubber in concrete is considered one of the methods with a positive environmental impact. Using crumbed rubber as a partial replacement material of concrete aggregate is found to possess many engineering applications and holds promise within the future. Replacing 5% of the sand volume by crumbed tyre rubber was used. Flexural behaviour of treated and untreated rubberized concrete slabs was investigated. Experimental program shows that the behaviour of the high strength rubberized concrete slabs can be improved by the used treatment methods. Beside that the coarser of the rubber particles, the more negative effect on the behaviour of the high strength rubberized concrete slabs.