Flexural Behavior of a Composite Concrete Castellated Double Channel Steel Beams Strengthening with Reactive Powder Concrete. Tikrit j. eng. sci. [Internet]. 2024 Apr. 12 [cited 2026 Sep. 9];31(2):28-42. Available from: https://www.tj-es.com/ojs/index.php/tjes/article/view/1279