# What is Spandrel Beam

## Basic Principles of Concrete Structures

### Chapter 1. Introduction

This is a textbook for civil engineering students. Understanding the behaviors of concrete structures has always been a major part of civil engineering education. This chapter gives an overview of the most important concepts and theories which make up the basic principles of concrete structures.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 2. Mechanical Properties of Concrete and Steel Reinforcement

Both stiff reinforcement and steel bars can be used in reinforced concrete members.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 3. Bond and Anchorage

As illustrated in Chap. 1, the prerequisite for combined action of concrete and steel bars requires a strong enough bond between the two materials to sustain the shear stress (called bond stress) caused by deformation difference (or relative slip) along the concrete-steel interface.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 4. Tension and Compression Behavior of Axially Loaded Members

Members subjected to axial tension at the geometric centers of their cross sections are called axially tensioned members. Typical examples in reinforced concrete structures include tensioned web elements and bottom chords in trusses, tie bars in arches, walls of internally pressured tubes, and sidewalls of tanks. Members subjected to axial compression at the geometric center of their cross sections are called axially compressed members. Typical examples are middle columns in multibay and multistory structures mainly sustained by permanent loads, compressed web members, and chords in trusses only loaded at the joints. Figure 4.1 illustrates common engineering applications of axially loaded members.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 5. Bending Behavior of Flexural Members

Flexural members are widely used in civil engineering shown here as reinforced concrete slabs, beams, stairs, and foundations in Fig. 1.4, retaining walls in Fig. 5.1, and girders, bent caps, and crash barriers in beam bridges in Figs. 5.2 and 5.3. Although flexural members have various section shapes, eg, rectangular section, T-shaped section, box section, I-shaped section, and channel section, they can generally be categorized into two types according to their mechanical properties: rectangular and T-shaped sections (Figs. 5.4 and 5.5). Circular or ring sections are separately used in practice.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 6. Compression and Tension Behavior of Eccentrically Loaded Members

In an eccentrically loaded member, the axially compressive load Nc or axial tension load N.t is applied at an eccentricity e0 on the member (Fig. 6.1a), which is equivalent to the combination of an axial load and bending moment M = Nce0 or M = Nte0 (Fig. 6.1b). The eccentrically loaded members include the eccentrically compressed members and the eccentrically tensioned members.
×
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 7. Shear

Reinforced concrete structural members such as beams, columns, tie bars, and walls are subject to two types of failure: (1) normal section failure by bending and (2) inclined section failure by shear. Generally, bending moment and shear force appear in a member simultaneously. However, which type of failure will happen depends on which internal force exceeds the corresponding bearing capacity of the member.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 8. Torsion

Torsion is one of the basic loading types of structural members. The spandrel beam in frame structures (Fig.8.1a) and the canopy beam (Fig.8.1b) are two typical examples of torsional members. Torsion seldom occurs by itself. Generally, there are also bending moments and shearing forces. But it is helpful to study the mechanical behavior of reinforced concrete members under pure torsion for the best understanding of mechanical behavior of reinforced members under combined torsion, shear, and bending. So, in this chapter, pure torsion-reinforced concrete members are studied first.
×
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 9. Punching Shear and Bearing

Various slabs in reinforced concrete structures, such as flat floor slabs, spread footings, and pile caps (Fig. 1.4), may fail in the patterns shown in Fig. 9.1, under local compressions, which are perpendicular to the slabs and of high intensity . When the failure happens, circumferential cracks will appear on the top and bottom surfaces, and a truncated pyramid surrounded by the circumferential cracks will (or tends to) be separated from the surrounding part in the force direction. This type of failure is called punching shear failure, and the local load is called punching shear load; the dropped-out part is called punching shear failure pyramid.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 10. Prestressed Concrete Structures

Prestressed concrete is made by introducing compressive stresses (prestress) into areas where an external load will produce tensile stresses. Before the established compressive stresses (prestress) offset, the concrete is not subjected to any tensile stresses.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 11. Serviceability of Concrete Structures

In the design of new concrete structures or in the appraisal of existing concrete structures, calculation for load-carrying capacity should be performed for all structural members in case any concrete members have reached their ultimate limit states due to strength failure or buckling. Concrete members can also reach their serviceability limit state, which would indicate a large deformation or undesirable vibrations or excessive crack width. Thus, to meet the functional requirements of the structures, it is necessary to control the deformation and the crack width and restrict their deviation within reasonable limits.
Xianglin Gu, Xianyu Jin, Yong Zhou

### Chapter 12. Durability of Concrete Structures

Irreversible changes can occur to concrete structures due to combined environmental and service loads. This is caused by complex physical and chemical actions in addition to direct mechanical loads.
Xianglin Gu, Xianyu Jin, Yong Zhou