An experimental and numerical study for investigating the promising stratified reinforced concrete slabs

It is well known that through the structural design, the safety and economic considerations of the project represent major factors, which must be always in mind. From this point of view, the concept and idea of "Stratified Concrete" were developed. Stratified Concrete consists of two or more types of concrete; in particular, composite materials consisting of High Strength Concrete (HSC) and Normal Strength Concrete (NSC). This study showed the flexural behavior for stratified sections (HSC-NSC) by taking a short time lap (1 h) between the two mixes to get a good bond between them. An experimental program was conducted to investigate the flexural behavior of NSC (25 MPa), HSC (60 MPa), and three HSC-NSC with the effect of changing the thickness of the HSC layer of slabs (20, 40, 75 mm) that had subjected to double static loads. As well, these slabs' experimental results were numerically verified. The most important achievement is the success of the idea of casting different strengths of concrete layers using a short time interval to improve the bending behavior of the slabs, and reach the superior thickness of the HSC layer, which represents almost a quarter of the slab thickness.