LCI Preconstruction & Estimating Training Manual

11/22/2017

Steel Composition

Steel Composition

Structural Components

• Iron + Carbon = Steel • Carbon: 0.2% - 2.4% • Carbon content determines type properties

Iron

Carbon (0.2% - 2.4%) Other Metals

Iron

Beams (1)

- Strength - Ductility -Hardness

What is a beam? • Structural element capable of withstanding flexural loads • Flexural loads cause a bending moment • Loads carried by beams: ▫ Self weight ▫ Gravitational loads

Carbon

▫ Wind loads ▫ Dead loads ▫ Lived loads ▫ Earthquake loads

Common Types of Steel Members

Beams (2)

• Concrete beam experiences three main phases before failure • Cracking Moment ▫ Concrete first cracks • Yielding Moment ▫ Flexural steel reinforcement reaches yield stress • Nominal Moment ▫ Ultimate moment capacity of beam before failure • Design criteria: ▫ Nominal Moment (multiplied by a safety factor) greater than Required Moment

Shape

Name

Purpose

Images

I

W Sections

Columns and Beams

L

Angles

Supports

C

Channels

Trusses

PL

Gusset Plate Splice Plate

Connecting beams

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