M2 - Reinforced Concrete Design Parameters

Girders

structural member bigger than joist and supports 2 beams

Beam

• structural member that supports slab (horizontal)

• transmits load from slab to columns

Column

• structural member that supports slab and beam (vertical)

• transmits loads from beam to foundations

Joists

structural member that supports girders

Foundation

structural member that spreads column load into soil

Slab

transmits load horizontally to beam

ACI - 318

American Concrete Institute

National Structural Code of the Philippines

NCSP

Permanent Loads

classification of load where the load is at a fixed position

Variable Loads

classification of load where the load is a live load

Accidental Loads

classification of load that is made from accidents

Live Load

• semi-permanent on the structure

• depends on intent of use on the area by the architect (functionality)

• ex. people, movable furniture

Superimposed Dead Load

ex. partition walls, fixed machinery, ceiling, floor finishes, topping (for concrete slabs), and water proofing (if applicable)

Self weight

• weight of the structure

• ex. weight of structural members

Dead Load

• permanent on the structure

• two types: self-weight and superimposed dead load

1.9 KPa (40 psf)

Residential

2.4 KPa (50 psf)

Offices

4.8 KPa (100 psf)

Assembly Areas and Commercial Areas

6 KPa to 10 KPa

Storage

0.76 KPa

Roof

Working Stress Design

• actual stress < allowable stress

• failure: allowable stress is exceeded

• factor of safety: identified as the ratio of ultimate stress over allowable stress

• more conservative but more expensive structure

Strength Design

• factored resistance greater than or equal to factored load effects

• failure: ultimate strain is reached

• factor of safety: load factors that increase design loads cause failure

• strength of members is computed at ultimate capacity

• internal forces are computed from the factored loads

• smaller sections and less reinforcement