Amr Shaat

• PhD
• Professor at Ain Shams University

The primary objective of this study is to precisely characterize the behavior of double bracket-to-circular Hollow Section (CHS) column joints due to combined internal forces resulting from double tensile loading in opposite directions. In order to accomplish this goal, an experimental program consisting of eight test specimens has been carried out...

Strengthening of hollow structural sections using through-bolts is a cost-effective and straightforward approach. It's a versatile method that can be applied during both design and service phases, serving as a non-disruptive and budget-friendly retrofitting solution. Existing research on axially loaded hollow sections T-joints has demonstrated that...

Circular hollow sections (CHS) are widely used in construction, particularly in space structures. This paper aims at investigating the feasibility of employing a machine leaning approach to predict the axial strength of longitudinal branch plate-to-CHS connections subjected to branch loadings. Using nonlinear finite element analysis, numerical mode...

Design optimization of box girder bridges maximizes the infrastructure's economic impact. Box Girder Composite Sections (BGCSs) are usually used in large-span bridges. This study aims at evaluating the behaviour of different parameters affecting the behaviour of steel-concrete box girders. A non-linear finite element model (FEM) is developed to stu...

Circular Hollow Section (CHS) columns are usually used in high-rise buildings. International design specifications usually overestimate the design of the beam-to-CHS column branch plate connections. This paper numerically investigates the behavior and strength of beam-to-CHS column branch plate connections using a finite element (FE) model. The FE...

This paper presents an experimental investigation of beam-to-CHS column branch plate connections subjected to eccentric shear loading. It is observed that such connections generally experience a significant decrease in capacity due to the low deformation limit of the hollow section. To increase the capacity of such connections, various stiffening t...

An experimental program is carried out to examine the effects of different factors on the slip and stress distribution of concrete slabs in composite beams. A total of ten steel-concrete composite beams with a span of 4.80 m are tested to find the effects of the type of shear connectors and the concrete slab reinforcement on the behaviour of compos...

Hollow Flange Channels (HFC) have been known for their higher capacity when compared to open flange C-sections. On the other hand, the small stiffness of HFC slender web compared to their flanges limits the bending capacity to the lateral distortional buckling (LDB) strength. Welding web stiffeners can limit the web distortion and enhance the bendi...

A nonlinear finite element model (FEM) was developed using ABAQUS 6.14 to determine the behaviour of mono-symmetric steel-concrete composite (SCC) beams provided with angle or channel shear connectors. Also, validation of the results of the FEM against the experimental results is discussed in this paper. Moreover, the FEM will be used to calculate...

ARTICLE INFORMATION ABSTRACT Introduction Steel-Concrete Composite (SCC) beams are formed by attaching two different materials (steel and concrete) using the shear connectors at the interface. Shear connectors are used to reduce the slippage at the steel-concrete interface. The degree of composite action is a major concept for the design of composi...

Nowadays, longitudinal branch plates are used as structural members in several engineering applications to connect brace members to Circular Hollow Section (CHS) chord members, which are widely employed due to their aesthetical appeal and efficiency. At ultimate limit state, the failure mechanism of T-type branch plate-to-CHS connections is charact...

In this study, an experimental investigation into the behaviour of steel tubular poles partially filled with concrete was conducted. A total of nine specimens were tested as cantilever poles under flexural loading. The main parameters of the tests are the diameter-to-thickness ratio [D/t = 57, 80 and 101] and the ratio of concrete filling length me...

Carbon fiber reinforced polymer (CFRP) laminates are widely used in strengthening reinforced concrete slabs, beams and columns. However, the application of this advanced composite material to strengthen steel structures is still evolving, and more research is needed to facilitate deployment. This paper presents the results of an experimental progra...

Although several studies in the field of steel-concrete composite beams reported that the effective concrete slab width depends on the loading stage of such beams (i.e. serviceability and ultimate stages), international codes have not considered it yet. In this respect, a nonlinear finite element model was developed using ABAQUS 6.10 and validated...

This paper investigates the behaviour of Hollow Square Section (HSS) beam-columns strengthened using Carbon Fiber Reinforced Polymer (CFRP) plates. Finite element model was developed and verified using experimental results. A parametric study was carried out to examine the effect of column slenderness ratio, HSS size, load eccentricity value and th...

“Retrofitting steel structures is gaining a high demand in many cases. Such as the increase in applied load or corrosion and fatigue problems. Retrofitting steel structural elements using adhesively bonded Carbon Fibres Reinforced Polymers (CFRP) has attracted more research attention worldwide. Due to their high elastic modulus carbon fibres are pr...

The axial load capacity and the stiffness of a rectangular hollow structural section (HSS) can be increased by adhesively bonding carbon fiber reinforced polymer (CFRP) plates to the outer surface of the steel tube. Experimental studies showed that two different failure modes generally occur for such a strengthened tube, the first mode was debondin...

An experimental study is carried out in this paper to investigate the validity of using lightweight concrete (LWC) slabs in steel concrete composite (SCC) beams and compare their behaviour with the normal weight concrete (NWC) slabs. In this respect, four composite beams with channel shear connectors were tested in four-point bending to study the e...

This paper presents the results of an experimental investigation into the behaviour of eccentrically loaded steel columns strengthened using high-modulus carbon fiber-reinforced polymer (CFRP) plates. Nine hollow square section (HSS) slender columns, 48x48x 2 mm with a constant slenderness ratio of 120, were eccentrically loaded to failure. Three e...

T-joints of circular hollow steel sections (CHS) with large brace-to-chord diameter ratios usually fail in an outward chord buckling (ovalization) mode when subjected to brace axial compression. In this paper, a new technique is presented for increasing the joint capacity where radial through-bolts are used to laterally brace the chord member and d...

Steel structures and bridges often need strengthening due to increased life loads, or repair due to corrosion or fatigue cracking. This paper explores the use of adhesively bonded Carbon Fibre Reinforced Polymers (CFRP) materials in rehabilitation of steel girders and columns through testing 13 girders and 82 columns. The first part of the paper in...

Joints have usually been the challenging aspect for the design of tubular structures. The stiffness of hollow section joints usually comprises an important limitation for the designer. Therefore, increasing the joint stiffness by controlling the local ovalization at the vicinity of joints is expected to improve the economic aspect of tubular struct...

Increasing the joint capacity of tubular structures has always been a challenge for designers because of their closed nature. This paper investigates a new technique for strengthening the circular chord at the T-joint location against ovalization when subjected to brace member compression loads. The strengthening technique is based on bracing the c...

The effectiveness of through-wall bolts is examined for strengthening T-joints of rectangular hollow steel sections. This is accomplished by controlling the web outward buckling of the chord under the brace axial load. The study examined the effect of the number and pattern of bolts, as well as the web height-to-wall thickness (h/t) ratio of the ch...

This paper describes the behaviour of axially loaded short and long square hollow structural section (HSS) columns, strengthened with carbon fibre reinforced polymer (CFRP) sheets. Twenty-seven short-column and five long-column HSS specimens were tested. The effect of CFRP sheet orientation in the longitudinal and transverse directions was studied...

Increasing the joint capacity of tubular structures has always been a challenge for designers. The closed nature of these tubular sections does not allow for welding conventional stiffeners. This study aims to examine a new technique of strengthening the sidewalls of the tubular chord at the T-joint location against outward buckling. The strengthen...

This paper presents an experimental investigation into the flexural behaviour of masonry walls that have been reinforced using near-surface mounted (NSM) or externally bonded (EB) reinforcement, under out-of-plane loading. The study simulates retrofitting applications and also proposes the NSM technique for new wall construction, using pre-grooved...

This study investigates the strengthening of intact steel–concrete composite girders and the repair of notched steel beams, using carbon-fibre-reinforced polymer (CFRP) materials with Young's modulus varying from 150 to 400 GPa. Three large-scale (6100 mm long) steel–concrete girders scaled down (4:1) with accurate proportional dimensions from a br...

This paper presents the results of an experimental investigation into the behavior of slender steel columns strengthened using high-modulus (313 GPa), carbon fiber-reinforced polymer (CFRP) plates. Eighteen slender hollow structural section square column specimens, 44×44×3.2 mm, were concentrically loaded to failure. The effectiveness of CFRP was e...

This paper presents the results of an experimental study on the repair of artificially damaged steel-concrete composite beams repaired using adhesively bonded carbon-fiber-reinforced polymer (CFRP) sheets. Eleven, 2 m long, beams composed of W150×22 steel sections with 465×75 mm concrete slabs were tested in four-point bending. Severe damage was fi...

This paper presents results of a non-linear finite element analysis of axially loaded slender hollow structural section (HSS) columns, strengthened using high modulus carbon-fiber reinforced polymer (CFRP) longitudinal sheets. The model was developed and verified against both experimental and other analytical models. Both geometric and material non...

This paper presents an analytical model developed to predict the behavior of concentrically loaded cold-formed square hollow structural section (HSS) slender columns, strengthened with high-modulus carbon fiber reinforced polymer (CFRP) sheets. The model predicts the load versus axial and lateral displacements, and accounts for plasticity of steel,...

This paper presents results of a finite element modeling (FEM) of axially loaded long hollow structural section (HSS) steel columns, strengthened using carbon-fiber reinforced polymer (CFRP) sheet applied in the longitudinal direction. The model provides a lower bound solution as it ignores the contribution of CFRP on the inward buckling face of th...

This paper describes an analytical model developed to predict the behaviour of axially loaded slender members composed of steel hollow structural sections (HSS), retrofitted with carbon-fibre reinforced polymer (CFRP) composite sheets. A previous experimental study by the authors showed that gain in strength due to CFRP retrofitting was highly sens...

This study investigates the experimental behaviour of axially loaded slender steel columns composed of square Hollow Structural Section (HSS), and strengthened using high modulus-carbon fibre-reinforced polymer (HM-CFRP) plates. The effectiveness of HM-CFRP system is examined in strengthening columns with different slenderness ratios (46, 70, and 9...