## 1 Introduction  
In the development of civil engineering, the increase in critical sections is essential for the improvement and strengthening of the critical section. One of the most significant aspects is the over-reinforced section in the structure. However, due to various reasons, improvement is essential in over-reinforced members to prevent brittle failure and undue aging. With this improvement, the beams possess higher ductility and stiffness, including high energy absorption to carry extra loads [1; 2]. Notably, the most conventional techniques for the design of flexural beam in the brittle failure of concrete are not permitted by several international codes of practice [3; 4] due to the low ductility of the members. According to ACI 318-02 and AS3600 [3; 4], the reinforcement ratio of the flexural reinforced concrete beams is classified into three categories, which may be balanced, under-reinforced, and over-reinforced. Therefore, the development of the over-RC beams can be obtained by replacing the steel bars in compression with quality materials, which exhibit better performance. The section of the replacement material will depend on the method of the section development. Moreover, several methods were used in the past with various degrees of success. The methods included helical reinforcement [5; 6; 7; 8], short stirrups with/without steel fiber [9], hybrid system, hybrid reinforced concrete beams. These beams consisted of two or three layers of diverse concrete strength levels. This range of strength could be seen from the top section made of high strength concrete (HSC), with a bottom layer, which was made of normal strength concrete (NSC) [10], and an external bonding with a steel plate in the side of the RC beam [11; 12]. The steel plate bonding in compression was the current method. Overall, these methods were used to avoid brittle behavior and crushing failure. The use of helical reinforcements in the critical zone at the mid-span of the beam was one of the most important methods to develop the over-reinforced beam [13; 14]. However, the studies conducted on the confinement of columns have recently been the basis of the development of the confined compression zone in beams [15; 16]. Accordingly, further investigation on the behavior of confined normal strength concrete (NSC), high strength concrete (HSC), and pre-stressed beams are required [6; 7; 16; 17; 18]. [PERSON] and [PERSON] [5] observed a linear increase in the spalling-off loads and decrease in ultimate load as the helical pitch increased. However, the decrease in helical pitch was due to the increase in displacement. They also reported that the failure yields and deflections were reduced with the increase in compressive strength of the concrete. This was followed by a significant decrease in the ductility index as the concrete compressive strength increased. Overall, it was indicated that the increase in the ratio of longitudinal reinforcements would increase the displacement ductility index, allowing the occurrence of a higher ultimate in the beam [8]. Several other findings were also developed on the installation of short stirrups as confinements [19]. Specifically, [PERSON] and [PERSON] reported that helical reinforcements had higher effectiveness compared to short stirrups to improve the flexural capacity and displacement ductility index of the confined concrete [6]. Further studies on the hybrid system involved the use of different steel bars types, including normal reinforcement and Fiber Reinforced Polymer FRP bars, as recorded by [PERSON] et al. (2017) [20]. It was found in their study that high strength concrete and ultra-high-strength concrete were reinforced with glass fiber reinforced polymer (GFRP). It was also found that the highly reinforced beams exhibited a higher level of ductility compared to the under-reinforced beams. Following that, ultra-high-strength concrete beams recorded higher energy absorption potentials compared to the high-strength beams with the same amount of reinforcement [20].