Reinforcement Length Research Articles

Recent Advances in Laterally-Loaded Piles within Mechanically-Stabilized Earth Walls

Pile foundations have been increasingly installed within mechanically-stabilized earth walls (MSE) on rocks or compressible soils to support structural loads. Integral abutment bridges, sound walls, and traffic signs are common examples of the structures supported by pile foundations installed within or behind MSE walls. These structures are often subjected to lateral loads resulting from earthquakes, traffic loads, wind loads, and/or thermal expansion and contraction of bridge girders. Typical approaches available to design MSE walls are limited to MSE walls without pile foundations present within reinforced fill. To minimize the interaction between piles and the MSE wall, designers often suggest to place the piles at a distance of six to eight times the pile diameter and/or isolate the piles from the MSE wall by using corrugated pipes. These suggested designs lead to increasing the cost of projects by increasing the length of bridge spans or the diameter of piles and requiring pile embedment. Recently, several studies have been conducted to understand the interaction between piles and MSE walls when the piles are constructed within and close to wall facing. This paper provides a literature review on full-scale tests, reduced-scale tests, and numerical studies of piles constructed within or behind MSE walls. The review will focus on the effects of three key influence factors on lateral capacities of laterally-loaded piles and facing deflections of MSE walls including the plie location behind the wall facing, the ratio of the reinforcement length to the wall height, and the stiffness of the reinforcement layer. This paper will also discuss the available approaches to estimate the forces in the reinforcement layers and the lateral earth pressures behind the MSE wall facing due to the laterally-loaded piles.

Flexural performance of reinforced HS-HVFA-SCC beam with spliced plain bar

This research presents the use of flexural performance criteria for determining the required spliced length of tensile plain bar embedded in unconfined high strength-high volume fly ash-self compacting concrete (HS-HVFA-SCC) beam. Subsequently, the obtained splice length is compared with the splice length database of other concrete types. For the purpose of the investigation, five beams are designed with various spliced bars within the pure bending area. In addition, a beam with continuous bar is prepared as a reference beam. The beams are tested by a four-point loading scheme. The results show that splice lengths within a 342–570 mm (34.2db–57db) range provide sufficient development of strength in the reinforcements to sustain a higher flexural load than the reference beam. However, in term of stiffness and ductility, only beams with a splice length of at least 380 mm (38db) are superior compared to the reference beam. Based on the above consideration, the minimum splice length of tensile plain reinforcement for the investigated beams is 380 mm (38db). Comparison of the result with other concrete types suggests that the required splice length of tensile plain bar embedded in HS-HVFA-SCC follows the equations for estimating splice length of general concrete and self-compacting concrete (SCC) even though the equations are derived for deformed bars. This finding implies that an efficient splice length in HS-HVFA-SCC beam can be expected.Article HighlightsHS-HVFA-SCC beam with a lap-spliced plain bar of 38db gives an equal flexural performance to the beam with continuous bar.The required splice length of plain bar in HS-HVFA-SCC beam is comparable to that of deformed bar in other concrete types.An expected efficiency of splice length can encourage the use of HS-HVFA-SCC for a variety of structural applications.

Numerical Analysis of the Deformation Behavior of Geogrid-Reinforced MSE Wall Having FHR and SPT Wall Facing

The mechanically stabilized earth (MSE) wall has been widely used globally for several decades now. The study on MSE wall is continuously growing as well as various innovations on its designs and techniques. The natural complexity of soil behavior makes the study on MSE wall system challenging for researchers. One of the factors that affect the deformation behavior of MSE wall structure is the wall facing system. Hence, this study is undertaken to investigate the deformation behavior of geogrid-reinforced MSE wall, having full height rigid (FHR) and segmental panel-type (SPT) wall facing, using finite element method (FEM) in Plaxis 2D program and small-scale experimental study. Both numerical and experimental models are using discrete geogrids reinforcement with three different reinforcement length ratios of 1H, 0.7H and 0.5H (where H is the wall height). The results from the series of numerical analysis and experimental tests showed that the vertical displacement on top of the MSE wall and the horizontal displacements of the FHR facing were smaller than those of the SPT wall facing, regardless of the reinforcement length. In addition, the reinforcement length has minimal effect on settlement for MSE wall with FHR facing but is more visible for MSE wall with SPT wall facing. The magnitude of the reinforcement effect may not be great in this study because the MSE wall models are only 0.60m high. But it is expected that the higher wall height might induce greater reinforcement length effect.

The development length of tensile reinforcement embedded in High Volume Fly Ash-Self Compacting Concrete (HVFA-SCC)

• The development length of reinforcement in concrete is affected by the concrete types. • The observed bond failure in the beams with and without stirrups are splitting and slippage, respectively. • Stirrup increases the bond strength of HVFA-SCC to the reinforcement. • The proposed model gives a good estimation to the experimental results. This research evaluates the development length of tensile reinforcement in High Volume Fly Ash-Self Compacting Concrete (HVFA-SCC), which is a new type of concrete combining SCC and HVFA concepts. The development length of reinforcement is an important supportive property applied to HVFA-SCC, as a structural element. To ensure good load transfer between reinforcement and concrete, a sufficient development length is essential, with the length requirements being specified in the codes, formulated based on the bond strength of normal concrete experiments. Previous studies discovered that the bond strength of HVFA-SCC was greater than normal concrete, subsequently affecting the development length requirements. Therefore, this study proposes an equation to determine the development length required for reinforcement embedded in HVFA-SCC beams. Data were obtained from beam analysis, with several tests being carried out on 42 beams having the dimensions 150 × 250 mm and length 2 m, respectively. The investigated parameters were the reinforcement diameter and splice lengths, as well as the confinement effects of stirrups along the lap splice. The proposed equation was then compared with those suggested in the literature for other types of concrete. The results showed that the proposed equation gives a closer estimation to the experimental results compared to previous equations suggested in the literature.

Numerical Limit Analysis of the Stability of Reinforced Retaining Walls with the Strength Reduction Method

The failure mechanism of MSE (mechanically stabilized earth) walls was studied via numerical analysis with the finite element strength reduction method, which was verified as an effective technique by simulating the experimental results reported in previous papers. The finite element program was applied to explore the effects of reinforcement, geometry, and seismic parameters on failure mechanism control at the design stage of MSE walls to avoid the unavoidable errors experienced in common numerical analysis caused by the assumptions of the failure mode and complex input parameters. The research parameters included the wall height, length, and spacing of the geogrid-reinforced retaining wall and seismic load. The results indicated that the wall height and reinforcement length play a major role in failure mode change. When the reinforcement length is less than 2 m, overturning failure could occur, which was unrelated to the other parameters in all cases studied in this paper. In this paper, the parametric study results were presented by evaluating the critical reinforcement length, generating the failure surface pattern, and summarizing design recommendation.

Response surface methodology for the optimization of the effect of fibre parameters on the physical and mechanical properties of deleb palm fibre reinforced epoxy composites

Irrespective of the many advantages of Epoxy resins, such as a wide variety of material qualities, ease of processing, little shrinkage during cure, and good adherence to various types of fibres, its application can be further enhanced by improving its mechanical properties. Although previous studies have considered the use of different natural fibres, however, in this study, for the first time Deleb palm fibre was employed as reinforcement on Epoxy, with the purpose of increasing its physical and mechanical qualities due to some of its elemental composition. The optimum formulation of fibre parameters for the development of Epoxy-Based reinforced Deleb palm fibre composite was determined using Response Surface Methodology (RSM). The influences of fibre weight composition of 30–35 wt% and fibre length of 1–5 mm on the physio-mechanical properties: tensile modulus, tensile strength, flexural strength, impact energy and water absorption were investigated using RSM based on Central Composite Design (CCD). The RSM revealed that the fibre reinforcement composition of 38.3 wt% and fibre reinforcement length of 3 mm produced the optimum Epoxy-Deleb palm fibre composite with tensile modulus of 260.365 MPa, the tensile strength of 12.485 MPa, the flexural strength of 25.704 MPa, impact energy of 0.882 J, and water absorption of 0.369%. The results showed that the unique properties of Deleb palm fibre have effect on the physio-mechanical properties of the Epoxy-Delab fibre composite.

Investigation of Tensile Lap-Splice Hybrid Steel Bars Used in RC Beams under Flexure

During the last two decades, fiber reinforced polymer (FRP) reinforcing bars for concrete structure has been extensively investigated and a number of FRP bars are commercially available. Using glass fibers and unsaturated polyester resins, steel fiber reinforced polymer composite bars (SFCB) were manufactured and introduced to the commercial market. Lap splice of such bars must be thoroughly investigated. Limitations of steel reinforcement lengths available from the plant (generally 12 m), causing the construction actors to splice the reinforcement. The simplest and easiest way is to make a lap splice, which made overlap by a certain length is called the developing length of lap splice bar. The main objective of this research using the concept of material hybridization, is to investigate the effect of bar diameter after adding fibers & code equation coefficients for best efficient developing length for tensile lap splice in beams under flexure. Nine RC beams were casted with dimensions of (25*40*420) cms and concrete strength of 300 kg/cm2. Beams were divided into three groups according to the fiber thickness added to 10 mms’ steel bars. First group contained three beams reinforced with hybrid bars of diameter 12 mms, 10mms steel coated with 2mms fiber. Beam one casted using bars with lap splice of 1.3*50φ, beam two casted using bars with lap splice of 1.3*55 φ & beam three casted using bars with lap splice of 1.3*60 φ. Second group contained three beams reinforced with hybrid bars of diameter 14 mms, 10mms steel coated with 4 mms fiber, beam one casted using bars with lap splice of 50φ, beam two casted using bars with lap splice of 55 φ & beam three casted using bars with lap splice of 60 φ. Third group contained three beams reinforced with hybrid bars of diameter 16 mms, 10mms steel coated with 6 mms fiber , beam one casted using bars with lap splice of1.3* 50φ , beam two casted using bars with lap splice of 1.3*55 φ & beam three casted using bars with lap splice of 1.3*60 φ . Beams were tested under four-point load to create a region of pure flexure stress. Load –deflection curves are presented along with percentage differences. Finally, conclusions were drawn and presented in this paper.

Effects of seismic amplification on the stability design of geosynthetic-reinforced soil walls

Many researches of geosynthetic-reinforced soil (GRS) walls under earthquakes demonstrate seismic acceleration amplification along the wall height. Current design methods of GRS walls often neglect the amplification effect on seismic stability and could yield an unconservative result. A pseudo-static method based on limit equilibrium (LE) analyses is carried out to calculate the distribution of required tension of seismic GRS walls following a top-down procedure. The connection load between the reinforcement and facing is correspondingly determined by the front-end pullout capacity. The approach assumes that the horizontal seismic acceleration coefficient varies linearly from the bottom to the top of GRS walls. The obtained results of the required tension involving the seismic amplification are in good agreement with other LE results in previous studies. Parametric studies are conducted to investigate the effects of horizontal seismic coefficient, primary and secondary reinforcement lengths and wall batter on the seismic stability of GRS walls. The seismic amplification yields more required reinforcement tension, significantly for the lower layers of the GRS wall subjected to strong earthquakes. In this situation, lengthening the bottom 1/2 of reinforcement layers could reduce the required tension to avoid tensile breakage of the reinforcements.

Performance of Modular-Reinforced Soil-Retaining Walls for an Intercity Railway during Service

In order to investigate the mechanical behavior of reinforced soil-retaining walls during service, this paper carried out a long-term remote observation test for 6 years on the modular-reinforced soil-retaining wall of the Qingrong intercity railway in eastern China’s Shandong Province. During the construction period, earth pressure boxes, flexible displacement meters, settlement pipes and displacement meters were buried to observe the soil pressure, reinforcement strain, horizontal displacement and settlement of the reinforced earth-retaining wall, respectively, for a long time; then, the results were analyzed to summarize its variation law. The results show that the reinforced earth-retaining wall was stable after one year of construction. It was determined that the strain of reinforcement in each layer decreased with time, culminating in a value of less than 0.88 percent during the 6th year. The maximum horizontal displacement of the wall was 11.43 mm and the maximum settlement of the wall top was 46.77 mm, which were 0.15% and 0.60% of the wall height, respectively. These research results can be applied to the construction and design of reinforced soil-retaining walls in high-speed railways. The effects of the elastic modulus of filler, the tensile modulus of reinforcement and the reinforcement length on the characteristics of the retaining wall were analyzed in the numerical simulation with PLAXIS2D. The results and analysis show: the elastic modulus of filler and reinforcement length have a significant effect on the horizontal displacement of the retaining wall. The results of this experiment can be referenced for engineering projects.

Numerical study on the pull-out behaviour of planar reinforcements with consideration of residual interfacial shear strength

Interface mechanics has always been a hot issue in geotechnical engineering, particularly in reinforced soil structures, but most existing numerical evaluations still used ideal elastoplastic models to predict the interaction of the reinforced soil surface, resulting in imprecise results. In this paper, based on a sophisticated analytical solution, a finite element analysis method was proposed for analysing the pull-out behaviour of embedded planar reinforcements considering the residual interfacial shear strength. In the numerical model, an improved cohesive element, which can precisely characterize realistic tri-linear shear slip models basing on a tabular function, was employed to simulate full-range progressive pull-out behaviour. Meanwhile, the parameters of the tri-linear shear slip model can be simply calibrated from pull-out tests using the proposed analytical solution, and the calibrated shear slip model can subsequently be used for modelling more complex problems. The finite element model was verified by two pull-out tests, and a parametric study was carried out for providing insights into the pull-out behaviour of embedded planar reinforcements. The results show that increasing the reinforcement length, the residual shear strength factor and the overburden pressure can improve the interface ductility and the ultimate pull-out capacity; Increasing the reinforcement stiffness improves the ultimate pull-out resistance increases but decrease the ductility.

Flexural behavior of UHPC-filled longitudinal connections with non-contacting lap-spliced reinforcements for narrow joint width

In this study, the longitudinal connections between precast concrete box girders were closure-poured by ultra-high performance concrete (UHPC), where were reinforced by three anchorage details of non-contacting lap-spliced reinforcements including straight bars, U-bars, and headed bars. UHPC made it possible to narrow the joint width because of its high mechanical properties. A testing procedure of four-point loading scheme was adopted to evaluate the flexural behavior of the UHPC-filled longitudinal connections. For comparison, the connections filled with fast-setting concrete (FSC) and self-compacting concrete (SCC) were also investigated. Experimental results indicated that 300-mm-width connections filled by UHPC materials efficiently accommodated the development length of lap-spliced reinforcements, performed a more deformable behavior, and obtained a higher flexural capacity. When a narrower joint width less than 200 mm was adopted, however, headed bars were not fully developed in UHPC-filled joint panels. UHPC-filled joint panels controlled interfacial cracks better and showed a 50% increase of cracking load than FSC-filled and SCC-filled joint panels. In terms of flexural capacity, the panels with U-bars exhibited the highest value, followed by those with headed bars and straight bars, regardless of different filling materials. A strut-and-tie model, considering the effective compressive strength and the effective height of concrete strut, was proposed to evaluate the flexural capacity of joint panels. The average ratio of experimental values to the calculated ones of all joint panels was 1.10.

Design of reinforced cohesive soil walls accounting for wall facing contribution to stability

Where granular materials are not easily available, local cohesive soils are increasingly employed in geosynthetic reinforced soil walls as a cheap and sustainable option. Conventional design methods do not yet account for the beneficial effect of cohesion in reducing the amount of required reinforcement. Similarly, the contribution of the face to stability is rarely accounted for, despite plenty of experimental evidence in its favour. In this paper, a semi-analytical method based on limit analysis is developed for the design of reinforced soil walls in frictional–cohesive backfills accounting for the wall contribution. A parametric analysis was conducted to evaluate the effect of soil cohesion and friction angle, facing batter, block width, location of the reaction force acting on the face, facing–backfill interface friction, facing–foundation interface friction and reinforcement length. Dimensionless design charts providing the required amount of reinforcement for lengths recommended in design standards are provided for both uniform and linearly increasing reinforcement distributions. It emerges that accounting for the presence of cohesion and the facing element can lead to significant savings in the overall level of reinforcement, and that tension cracks can be particularly detrimental to wall stability for highly cohesive soils so they cannot be overlooked in the design.

Assessment of seismic behavior of back-to-back mechanically stabilized earth walls using 1g shaking table tests

In current study, the effect of overlap length of reinforcements (LR) and arrangement of connecting two opposing walls to each other on the seismic behavior of back-to-back MSE walls (BBMSEWs) was investigated using reduced-scale 1-g shaking table tests. Results showed that fundamental frequency (ff) of BBMSEWs strongly depends on the arrangement of reinforcements and the ff value decreases with decreasing LR and separating two opposing walls from each other. It was also concluded that increasing the overlap length of reinforcements and separating the bottom half of two walls from each other can be two good solutions for reducing the possible acceleration amplification in BBMSEWs. The combination of a slant and a reverse curve with certain intersection point was observed as the failure surface in all the models. The geometry of failure surface was found to be unaffected by LR changes and only dependes on the arrangement of connecting two opposing walls to each other. On the other hand, the increase in ay values due to increasing LR and connecting two opposing walls to each other showed that the use of direct connection of two walls and applying a suitable LR can be considered as two suitable solutions to improve the seismic stability of BBMSEWs. It was also found that although the use of overlapping reinforcement instead of the direct connection of two walls to each other leads to increasing the lateral displacements, but it can be a good solution for reducing mobilized reinforcement forces in BBMSEWs.

Laterally-loaded pile-MSE wall system performance under different design configurations

The need for constructing a shallow or deep foundation (e.g. piles) in a mechanically stabilized earth (MSE) wall for superstructure support has increased. However, the performance of laterally loaded piles within the MSE wall and their interaction with soil and reinforcement are not fully understood. Limited full-scale tests and numerical studies have been conducted to evaluate the behavior of laterally-loaded piles within MSE walls. In this study, thirteen reduced-scale model tests were performed to investigate the effects of changing the wall configuration (wall height, and reinforcement spacing and length) and the pile location on the performance of the pile-MSE wall system under static lateral loads. This experimental study found that the piles in high walls could develop larger maximum compressive and tensile strains. Low walls resulted in larger wall facing deflections and maximum tensile strains in the geogrid reinforcement. Small reinforcement spacing and long reinforcement length resulted in higher pile lateral load capacities, smaller wall facing deflections, and smaller reinforcement tensile strains. The pile offset from the back of the wall facing is a critical factor that affected the pile capacity, the wall facing deflection, the reinforcement tensile strain, and the lateral earth pressure distribution behind the wall facing.

Neural network prediction of joint shear strength of exterior beam-column joint

Beam-Column joints are the critical locations in the reinforced concrete structures as they experience a massive amount of deformations under earthquake. The shear failure of the beam column joint should be avoided for the safety of the structure. In the present study, prediction of joint shear capacity of exterior Beam-column joint is proposed using artificial neural network (ANN). Experimental investigations performed by different authors have been examined and used to prepare the data sets for training, testing and validating the neural network. Parameters responsible for the shear strength of the exterior Beam-Column Joints are identified and the artificial neural network model is proposed to predict the joint shear strength. Input parameters for the ANN model are width and depth of the joint, concrete compressive strength, length of beam, top and bottom longitudinal reinforcement in the beam, yield strength of longitudinal reinforcement in beam, ratio of beam to column depth, joint Shear reinforcement index, beam bar index and column load index. The performance of the neural network model is evaluated by the statistical relations like Coefficient of correlation, Root mean square error and Scatter index. The proposed model is compared with an empirical formula and different equations suggested by the design codes. The results show that the proposed neural network model can effectively predict the joint shear strength of the Exterior Beam-Column joint.

Single pullout experiment and reinforcement properties of basalt fiber in vegetation concrete

Basalt fiber (BF) reinforced vegetation concrete (VC) technique has attracted the attention of researchers. In order to investigate the reinforcement properties of BF reinforced VC, the optimal BF length and content. Through the single BF pullout test and direct shear test, the properties of interfacial strength between BF/VC and the reliability of the formula for calculating the optimal BF reinforcement length are studied. It has been found that the designed equipment is an efficient method to obtain the interfacial peak shear strength and residual shear strength of BF/VC. Moreover, the direct shear test proves the feasibility of the formula, which is used as a basis for mixing BF length in engineering. The anchoring effect between the cement hydration product and the fiber in the VC changes the mechanical action between BF/VC and significantly improves the shear strength of the interface. Higher dry density effectively enhanced the peak tension of a single BF by 149.23%. The optimal BF length and content make the softening degree of vegetation concrete not evident, which improves the durability of VC engineering. The formula of optimum fiber reinforced length and empirical formula can be used as reference for mixing basalt fiber in practical engineering.

Interface bond strength performance of overlap joints within the corrugated pipes used in prefabricated bridges

This paper presents an experimental study of a novel composite structure used in prefabricated bridges. Corrugated pipes were used to improve the interface bond performance of the structure because of their excellent stiffening effect on the grouting material. Interface bond performance of overlap joints within corrugated pipes was explored by the load-displacement curve and load-strain curves. Ultra-High Performance Concrete (UHPC) and high-strength mortar were used as grouting materials. The diameter of steel bars, UHPC, high-strength mortar, strength grades of surrounded concrete, anchorage length, the diameter of the corrugated pipe, and lap length was taken as influential factors. Twenty specimens were designed for the pull-out test by using a larger cover thickness. The failure modes and the influence of different influential factors on the interface bond strength of each specimen were analyzed. The results show that the bond performance between UHPC and reinforcement was better than that of high-strength mortar and normal concrete, which can effectively improve the bond strength and reduce the basic anchorage length of reinforcement besides the design size of prefabricated members. In addition, the differences in anchorage length and lap length between the corrugated pipe grouting reinforcement were compared to the different specifications and prefabricated concrete members. Combined with the test phenomenon and analysis results, it is suggested that the anchorage length and lap length of connecting reinforcement should be reconsidered. Furthermore, the grouting effect under different diameters of corrugated pipe and reinforcement were compared. It is recommended that the corrugated pipe diameter should be four times that of the overlapping grouting reinforcement.

Analysis of the Working Performance of a Back-to-Back Geosynthetic-Reinforced Soil Wall

Back-to-back geosynthetic-reinforced soil walls (BBGRSWs) are commonly used in embankments approaching bridges and narrow spaces. However, the available literature and design guidelines for BBGRSWs are limited. The aims of this research were to develop a greater understanding of the working performance of BBGRSWs and to optimize the design method of a BBGRSW to ensure the cost-efficiency as well as the stability of the structure. On the basis of a monitored BBGRSW structure located in China, we established a numerical model. The parameters of the materials used in the actual project were determined through triaxial and tensile tests. The numerical results were compared with the measured results in the field to verify the correctness of the selected parameters. Two parameters were investigated by the FEM method: the reinforcement length and the arrangement. The FEM analysis indicated that post-construction deformations such as displacement and settlement could be reduced by reinforcing the same layer on both sides. Longer reinforcements were needed to achieve the same performance if the reinforcements were cross-arranged. Thus, BBGRSWs can have a superior performance if the reinforcements are connected in the middle from both sides. Even with longer reinforcements, the safety factor of the wall with a cross-arranged reinforcement was smaller than that with same-layered reinforcements.

Borehole Magnetometry Test for Evaluating a Caisson’s Reinforced Depth: Experimental Results and Theoretical Modeling

Abstract The borehole magnetometry (BM) test was performed to evaluate the foundation reinforcement depth at a site where a telecommunication tower is supported by a single 2.3-m-diameter caisson foundation of known as-built design. An optical televiewer probe containing a three-axial fluxgate magnetometer was lowered into a vertical borehole 2.35 m distant from the center of the caisson and the profiles for the total magnetic field flux density, and its vertical component were acquired and used to generate, by subtracting the International Geomagnetic Reference Field background, the profiles for the total, BA, and vertical component, Bz,A, anomalous magnetic field. Four distinct graphical methods were used to evaluate the reinforced depth from the anomalous profiles and their first- and second-order derivatives. Two of the methods, including the one proposed in this study, based on locating the inflection points in the derivative profiles, evaluated the reinforced depth very close to the as-built depth (8.0 m). The reinforcement intensity of magnetization was then evaluated using the BA profile and a method based on the bipolar model. Theoretical modeling of BA and Bz,A and the derivative profiles was then performed using a three-dimensional prismatic model. By comparing modeled and experimental results, the induced magnetization was found to be an unsuited modeling assumption, with remanent magnetization being a better representation of the magnetic field around the caisson’s steel reinforcement, in agreement with the theory, given the high Koenigsberger ratio for steel. Also, the modeling revealed the need for a more complex representation of the magnetic sources, with added prisms to represent the effects of a magnetically-noisy environment and above-ground structures, as well as the presence of inhomogeneity and polarization changes along the reinforcement length.

Reinforced Concrete Beams Strengthened in Flexure with Near-Surface Mounted 7075 Aluminum Alloy Bars

The flexural behavior of reinforced concrete (RC) beams strengthened with near-surface mounted (NSM) 7075 aluminum alloy (AA) bars was investigated through experimental testing. In particular, 10 RC beams strengthened with NSM AA bars and one control beam were tested under four-point bending loading. The experimental variables included NSM reinforcement ratio, bonded length of NSM reinforcement, end anchoring of NSM reinforcement, and type of bonding agent. The test results were evaluated in terms of the load-deflection curves, failure modes, ductility, and strains in NSM reinforcements, and the effects of different test parameters on the effectiveness of the proposed strengthening approach were discussed. In addition, analytical models were developed to predict the load-bearing capacities of strengthened beams failed by intermediate crack debonding and concrete cover separation, respectively. The RC beams strengthened with NSM AA bars exhibited a significant improvement in maximum load ranging from 35% to 120% over the reference specimen.