This manual is published in two volumes. Volume 1 includes design and analysis for columns, deflection, flexure, footings, seismic, shear, and two new chapters on deflection and strut-and-tie in accordance with ACI 318-11. Volume 2 includes design and analysis for anchorage to concrete in accordance with ACI 318-11.
Sp 17(11) The Reinforced Concrete Design Manual Volume 2
The development of reinforced concrete began with the commonly known inventions of Joseph-Louis Lambot, Joseph Monier, William Boutland Wilkinson, and Francois Hennebique in the nineteenth century. In turn, the development of concrete prestressing technology in the early twentieth century was initiated by Eugène Freyssinet.
The current rules for the use of classic reinforced concrete elements in the form of main bars parallel to the middle plane and auxiliary bars essentially located perpendicular to the main reinforcement are well-established and known thanks to the publications of The International Federation for Structural Concrete (fib), e.g., Walraven et al. [4] or American Concrete Institute, e.g., Taylor et al. [5,6]. These principles have also been described in detail, among others, in the works of Polish authors Kobiak and Stachurski [7,8,9,10], Knauff [11], and Starosolski [12].
These principles are used and developed in many studies of reinforced concrete elements. These studies concern both different types of reinforced concrete elements as well as experimental and computational research methods.
Tests of traditional structural elements reinforced with steel bars of the main reinforcement in tension and with usual stirrups in shear are the subject of many works. However, modern research on reinforced concrete beams focuses on the material modification of concrete and the material diversity of reinforcing bars.
An experimental and a numerical study were carried out on the flexural crack behavior of reinforced concrete beam members by Sandeep Das et al. [13]. The experimental investigation was focused on the effect of flexural crack by varying the percentage of tensile steel on beam sections. A computer vision-based data-driven numerical tool for crack representation and quantification was developed based on the real-time video surveillance data of the flexural testing on beams.
A study on the influence of shape memory alloys (SMA), glass fiber-reinforced polymer (GFRP), and steel longitudinal rebars on flexural and shear behavior of reinforced concrete beams was presented by Karimipour and Edalati [14]. The results indicated that using GFRP and SMA rebars improves maximum bending capacity and deformation, and prevents the rapid reduction in the bearing capacity after the maximum load point of beams.
An experimental investigation into the effect of GFRP needles as coarse aggregate partial replacement in concrete on the shear behavior of large-scale reinforced concrete beams was performed by Nie et al. [15]. The GFRP needles were obtained by cutting FRP waste into short-length randomly distributed reinforcing bars. An enhancement in the load-carrying capacity was observed in beams with helically wrapped needles, while beams with smooth needles showed a slight reduction in the load-carrying capacity. The presence of GFRP needles significantly increased the amount of total energy absorbed by the beams.
The concrete beams were tested to investigate the flexural performance of concrete beams reinforced with three different reinforcement bar type (hybrid, GFRP, and steel) and the five different reinforcement ratios by Said et al. [16]. The test results showed a significant enhancement in the maximum load-carrying capacity due to increasing the hybrid reinforcement ratio.
Research to evaluate the structural performance of two-layer fiber-reinforced concrete beams with glass fiber-reinforced polymer (GFRP) and steel rebars under quasi-static loads was carried out by Nematzadeh and Fallah-Valukolaee [17]. The results showed that adding fibers to the compression zone of the section led to a higher ductility in both GFRP rebar and steel rebar reinforced beams, while adding fibers to the tensile zone led to a higher ultimate flexural strength. An increase in the ratio of GFRP and steel reinforcement together with a greater concrete compressive strength in the layered beams enhanced their flexural performance in terms of load-carrying capacity, flexural stiffness, and ductility. Replacing steel rebars with GFRP ones led to a decrease in these parameters.
Research is being carried out on elements reinforced with traditional steel reinforcement surrounded by a concrete matrix additionally reinforced with a system of steel fibers or a mixed system of steel, polypropylene, or glass fibers. Smarzewski presented research on slabs, beams, and deep beams with/and without openings made of high-performance concrete and hybrid (steel and polypropylene) fiber reinforced high-performance concrete [18,19,20]. In these studies, the non-contact, three-dimensional, deformation measuring system ARAMIS [21] was effectively used.
In terms of research methods, the non-contact methods of recording the results and measurements of displacements and deformations are increasingly used. Liu et al. proposed a framework to optimize two-dimensional measurements in concrete structure models with a digital image correlation (DIC) system at different orders of accuracy [22]. A good example of using the DIC method is the work of Funari et al. [23]. With regard to reinforced concrete elements, the description and application of the DIC method has been systemically presented by Skarżyński et al. [24]. The application of DIC has been practically used in investigations of size effect in reinforced concrete beams with longitudinal steel and basalt bars but without shear reinforcement by Syroka-Korol and Tejchman [25]. The DIC technique was also applied by Suchorzewski et al. to visualize strain localization on the concrete surface of the longitudinally reinforced concrete beams with separately varying height and length, in order to investigate the size effect on nominal strength and post-critical brittleness [26].
However, there are examples of entwined reinforcement, also known as laced reinforcement. This reinforcement is used in reinforced concrete elements and is specially called laced reinforced concrete (LRC), Anandavalli et al. [27]. In this paper, an approach for finite element modeling of RC/LRC structural elements that are primarily under flexure was proposed. The approach considered RC/LRC as a homogenous material whose stress-strain characteristics were derived based on the moment-curvature relationship. Numerical studies on LRC beams were carried out and the results was compared with those of the experimental values.
The truss arrangement of bars increases the homogeneity ratio of the concrete-steel composition and thus strengthens the reinforced concrete elements not only in the places where diagonal cracks occur, but also in the entire element.
Experimental tests of reinforced concrete beams with conventional reinforcement and with appropriately mass equivalent truss-shaped reinforcement, each with a different reinforcement ratio of longitudinal reinforcement, were performed. It was assumed that the reinforcement mass balance determines the equivalence of conventional and truss reinforcement.
The beams of Series 1 and Series 2 were made of two lots of concrete mixes of the designed class C50/60. The beams and the material testing were made in accordance with the requirements of standard EN 206:2016 [32] and related standards [33,34].
where Mcr and Mo are the cracking and failure moments determined in the bending reinforced concrete cross-section, respectively for the linear elastic phase Ia and the limit phase III with rectangular stress distribution in concrete, see e.g., [4,35]; and c is the distance of the loading force axis from the support reaction force axis, Figure 2.
The ACI Reinforced Concrete Design Handbook provides dozens of design examples of various reinforced concrete members, such as one- and two-way slabs, beams, columns, walls, diaphragms, footings, and retaining walls. For consistency, many of the numerical examples are based on a fictitious seven-story reinforced concrete building. 2ff7e9595c