WORLD BOOK

Wednesday, December 16, 2020

SLENDER COLUMN

Friday, December 11, 2020

[Nasr_Younis_Abboushi] ACI 318M-08 Reinforced Conc(Bokos-Z1)Part 2

CONTENTS

CHAPTER 8 ONE-WAY SLABS

Structural concrete slabs are constructed to provide flat surfaces, usually horizontal, in building floors, roofs, bridges, and other types of structures. The slab may be supported by walls, by reinforced concrete beams usually cast monolithically with the slab, by structural steel beams, by columns, or by the ground. The depth of a slab is usually very small compared to its span

CHAPTER 9 TWO-WAY SLABS

When the slab is supported on all four sides and the length, , is less than twice the width, , the slab will deflect in two directions, and the loads on the slab are transferred to all four supports. This slab is referred to as a two-way slab. The bending moments and deflections in such slabs are less than those in one-way slabs; thus, the same slab can carry more load when supported on four sides. The load in this case is carried in two directions, and the bending moment in each direction is much less than the bending moment in the slab if the load were carried in one direction only.

CHAPTER 10 STAIRS

Stairs must be provided in almost all buildings, either low-rise or high-rise, even if adequate numbers of elevators are provided. Stairs consist of rises, runs (or treads), and landings. The total steps and landings are called a staircase. The rise is defined as the vertical distance between two steps, and the run is the depth of the step. The landing is the horizontal part of the staircase without rises.

CHAPTER 11 FOOTINGS AND FOUNDATIONS

Reinforced concrete footings are structural members used to support columns and walls and to transmit and distribute their loads to the soil. The design is based on the assumption that the footing is rigid, so that the variation of the soil pressure under the footing is linear. Uniform soil pressure is achieved when the column load coincides with the centroid of the footing. Although this assumption is acceptable for rigid footings, such an assumption becomes less accurate as the footing becomes relatively more flexible. The proper design of footings requires that 1. The load capacity of the soil is not exceeded. 2. Excessive settlement, differential settlement, or rotations are avoided. 3. Adequate safety against sliding and/or overturning is maintained

CHAPTER 12 DEVELOPMENT, ANCHORAGE, AND SPLICING OF REINFORCEMENT

In a reinforced concrete beam, the flexural compressive forces are resisted by concrete, while the flexural tensile forces are provided by reinforcement

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Wednesday, September 9, 2020

[Nasr Younis Abboushi] ACI-318M-08 Reinforced Conc(Bokos-Z1)Part1

CONTENTS

CHAPTER 1 REINFORCED CONCRETE STRUCTURES

CHAPTER 2 MATERIALS AND PROPERTIES

CHAPTER 3 DESIGN METHODS AND REQUIREMENTS

CHAPTER 4 FLEXIBLE IN BEAMS

CHAPTER 5 SHEAR IN BEAMS

CHAPTER 6 COLUMNS: COMBINED AXIAL LOAD AND BENDING

CHAPTER 7 SLENDER COLUMNS

1. Floor Slabs

Floor slabs are the main horizontal elements that transmit the moving live loads as well as the stationary dead loads to the vertical framing supports of a structure. They can be:

 Slabs on beams,

 Waffle slabs,

 Slabs without beams (Flat Plates) resting directly on columns,

 Composite slabs on joists.

They can be proportioned such that they act in one direction (one-way slabs) or proportioned so that they act in two perpendicular directions (two-way slabs and flat plates).

2. Beams

Beams are the structural elements that transmit the tributary loads from floor slabs to vertical supporting columns. They are normally cast monolithically with the slabs and are

Reinforced Concrete I Dr. Nasr Abboushi

structurally reinforced on one face, the lower tension side, or both the top and bottom faces. As they are cast monolithically with the slab, they form a T-beam section for interior beams or an L beam at the building exterior.

The plan dimensions of a slab panel determine whether the floor slab behaves essentially as a one-way or two-way slab

3. Columns

The vertical elements support the structural floor system. They are compression members subjected in most cases to both bending and axial load and are of major importance in the safety considerations of any structure. If a structural system is also composed of horizontal compression members, such members would be considered as beam-columns.

4.Walls

Walls are the vertical enclosures for building frames. They are not usually or necessarily made of concrete but of any material that esthetically fulfills the form and functional needs of the structural system. Additionally, structural concrete walls are often necessary as foundation walls, stairwell walls, and shear walls that resist horizontal wind loads and earthquake-induced loads.

5. Foundations

Foundations are the structural concrete elements that transmit the weight of the superstructure to the supporting soil. They could be in many forms:

 Isolated footing - the simplest one. It can be viewed as an inverted slab transmitting a distributed load from the soil to the column.

 Combined footings supporting more than one column.

 Mat foundations, and rafts which are basically inverted slab and beam construction.

 Strip footing or wall footing supporting walls.

 Piles driven to rock.

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