EFFECT OF CHEMICAL OXIDES COMPOUNDS IN RAW SEWAGE WATER ON CONCRETE STRENGTH

Abstract

Wastewater affects concrete structures, causing corrosion and disintegration of concrete, and then corrosion of iron inside concrete due to the presence of salts and chemicals in wastewater. It causes a lack of cohesion between it and the cement paste, and the concrete may crack and collapse. In addition, the presence of salts such as sulfates, chlorides, and sometimes carbonates has adverse effects on concrete. A number of cubes were taken and placed in a basin containing pure water for testing. A number of cubes were placed in a basin containing sewage water, and a number of cubes were placed in basins containing these solutions AL₂O₃ (Aluminium oxide), SiO₂ (Silicon dioxide), TiO₂ (Titanium dioxide), Fe₂O₃ (Iron oxide), K₂O (potassium oxide), MgO (Magnesium oxide), SO₃ (Sulfur trioxide), CaO (Calcium oxide), MnO (Manganese oxide), P₂O₅ (Phosphorus pentoxide)). and after checking the results in 7, 28, 56, and 90 days.  The result of the test was that it appears the elements that increase the compressive strength of concrete are (AL₂O₃, SiO₂, Fe₂O₃, and TiO₂) with a rate of 30% at 28 days, 39% at 56 days, and 43% at 90 days.  At the same time, the elements that reduce the compressive strength of concrete are (K₂O, MgO, SO₃, P₂O₅, MnO, CaO, and BOD) with a rate of  18% at 28 days, 24% at 56 days, and 29% at 90 days.