The precast concrete roofing slab produced from the local factory were below the Iraqi standard requirement (NO 1107-1988).
This study has been made to improve the production of precast concrete slabs by using(propylene – ethylene copolymer grid )which is a waste material produced from the base of polymer boxes .
The depended mix of the precast concrete slab in the local factory did not use the correct proportion ,tested mixes were redesigned and prepared to achieve the limited requirements . Propylene – ethylene copolymer grid was used to have better results, less costs, with protection of the environment from pollution ,where there is difficulty to remove it even when it is fully exposed to severe weather conditions .the manufactured slabs had dimensions of (800×800×40)mm and testing program extended to 60 days of age and comprised ,breaking loads, water absorption ,and impact resistance of concrete. The total number of manufactured samples was (55 slabs).
The test results indicated that the weigh ted mix proportions ((1:1.5:2.45) cement :sand : gravel ) with w/c=0.41 , superplasticizer(0.75 liter/100 kg of cement )and propylene –ethylene copolymer grid with a dimension (600×600)mm enhances the mechanical properties of concrete . It increased the breaking load by 81 % compared to ordinary production. while the impact resistance increased to 26 blows compared to 3 blows for the ordinary production. However, the polymer grid decreased the width and depth of cracks and maintained the integrity of the slabs after failure .