International Science and Technology Journal

Reinforced concrete is the basic material in construction and consists of a mixture of cement, water, aggregate (gravel, sand, or crushed rocks), and reinforcing steel. When concrete hardens, it becomes a strong and durable material mainly used to construct buildings, bridges, highways, and other structures. Therefore, the quality of the materials used in concrete manufacture significantly impacts the structures' behavior and durability. This research aims to study and compare the quality of the materials that make up reinforced concrete found in Benghazi from different sources, including local and imported ones. Local cement (El-Salaba from Benghazi factory and El-Borj from Zliten factory) and imported cement from Egypt (Beni Suef and Helwan) were studied, as well as aggregate (Al-Abyar and Ajdabiya quarries), sand (Shatt Al-Badin and Zueitina), locally manufactured steel bars (Misurata for Iron and Steel Factory and That Al-Imad Factory, Tripoli) and imported steel bars (Ezz from Egypt). Laboratory tests were conducted on all samples to match the quality of these materials with the British and American standard specifications to ensure the construction of stronger and durability concrete. The results indicated that the locally manufactured Al-Burj, Beni Suef, and Helwan cement imported from Egypt conformed to the specifications and obtained similar compressive strength and 27% higher than El-Salaba cement. The Ajdabiya aggregate also met the standard specifications, while the imported Ezz Steel bars from Egypt outperformed the rest of the locally manufactured types by obtaining a yield strength 38% higher than the rest of the locally manufactured samples. An economic feasibility study should be conducted to compare the cost of importing and producing cement and reinforcing steel bars. The quality control centers affiliated with the Libyan state should conduct periodic tests on locally produced cement and reinforcing steel bars and evaluate the imported ones to ensure that they conform to the specifications in the labor market................. Keywords: ..........Cement quality, aggregate, reinforcing steel bars, concrete, laboratory tests, Benghazi.