## 2 Experimental Work  
### Specimen Details and Testing Setup  
Four-point bending was applied to four full scales of simply-supported over-beams, which were fabricated and tested in the laboratory. All of the specimens have the same geometrical dimensions, as shown in Table 1 and Figure 1. The lengths, widths, and depths of the RC beams were 2400, 200 and 300 mm, respectively. The length of the shear span was 700 mm, and the shear-effective depth ratio was about 2.7 (a/d \(>\) 2.5). The specimens were over-reinforced with 5020 tension bars. This represents a steel percentage of 3.27%. The provided shear reinforcement consisted of a transverse reinforcement of 1706 and stirrups spaced center to center to the load points at the web shear at 50 mm, which was considered to be adequate for the avoidance of premature shear failure. The yield strength of the steel reinforcement that was adopted in [31]. To ensure that there was no further confinement provided by the stirrups, the middle zone between the load points was not provided with the stirrups. The longitudinal and transverse reinforcement was considered sufficient enough to ensure that the specimens would fail due to flexural compression in both undeveloped and developed cases. This is desirable for achieving the objective of this research, which is to investigate the over-reinforced responses of beams. Here, the control beam (CB) specimen was used to demonstrate the structural performance of an over-reinforced beam prior to development. Three developed specimens were fabricated. The bolt-plate arrangements of these specimens were carefully selected so that the behaviors of the beams remained identical. Thus, the BCSP-6, BCSP-10, and BCSP-15 beam series were developed with 6, 10, and 15 mm steel plates thicknesses, respectively. The tested steel plates were adopted in this study [32], using 24 bolts to bond the steel plates to the concrete. The size of the steel plate used was 1100 mm in length by 180 mm in width, and the bolt was 12 mm in diameter and 200 mm in length. The clearance of the holes on the plates was 12.5 mm [33], which was used for all of the beams, as shown in Table 1 and Figures 2 and 3. In the final casting, the steel formwork was used for all the beams, as shown in Figure 3. However, for the BCSP beams of the bolt-compression plates, two pieces of wood were placed under the plates in the process of concrete casting. After curing, the external plates were fixed to the cast-in sockets,with bolt clearance holes on the plates, which were provided to facilitate the location of tolerances. The bolts were then coated to the beam in order to prevent any slippage within the clearance holes of the plates, and additionally to avoid the buckling of the steel plate. Mixed design proportions of the concrete were used to acquire adequate compressive strength, which was 36.8 MPa. After curing for 28 days, as shown in Table 2, ten specimens were cast as concrete cubes (\(100\times 100\)) mm, and additionally a concrete cylinder (\(200\times 100\)) mm, for compressive and tensile strength testing, according to part 1 of B.S., 1997, and BS8110, 1986 [34; 35]. All the simply-supported over-reinforced concrete beams were tested under four-point bending over a span of 800 mm. A constant shear span to an effective depth was adopted for all tests. A MTS universal testing machine with a 4000 kN capacity and a 50 mm stork length was used to apply the static load. The load was transferred from the actuator to the spreader beam using a stub column that was 2000 mm in height. Figure 4 shows the experimental testing setup for one of the beam specimens. The dimensions and equipment used are also presented in Figures 1 and 2. Two electrical resistance strain gauges were attached at the top of the beams, directly underneath the position of the load cell, in order to measure the concrete strain. Additionally, the two strain gauges on top of the steel plate at the middle were used to measure the strain here.