The Recycling Use of Concrete Waste as Aggregate to Produce Different Types of Concrete

The present study depends on two types of concrete: the first and second samples belong to Portland cement with a high strength of 52.5 R, and ordinary Portland cement with a normal strength of 42.5 N, respectively. The physical tests for these two samples according to Iraqi Standard Specification No. 5 of 2019 were conducted. Whereas the third and fourth samples of concrete waste were taken from Mosul City and Al-Anbar Governorate. The concrete waste samples were broken into different-size particles as a fine and coarse aggregate using a mechanical crusher (Los Angeles). According to the Iraqi Standard Specification No. 45 (1984, the Physical and chemical tests for both fine and coarse natural aggregate and recycled concrete waste were conducted. The physical and mechanical results of the recycled aggregate testing samples were found to be within the limits of specifications, in which a reference concrete was made from the standard cement samples with natural aggregate for comparison. The natural aggregate was replaced with 100% recycled aggregate, and its behavior was studied through mechanical properties tests, including compressive strength, flexural resistance, and direct tensile resistance within 7 and 28 days. The results show a decrease in the compressive, flexural, and direct tensile strength in the subjected samples compared to the reference specimens. The study concluded that a 100% replacement ratio of coarse and fine recycled aggregate can be used successfully with different types of cement to obtain a new type of concrete that can be used in several engineering fields. The mechanical properties of the new concrete depend mainly on the type, class and quality of the natural cement even on the properties of the recycled aggregate.