Prepared by Theong MC

Frame consists of upright load bearing members such as posts in

timber, columns in concrete or stanchions in steel which are arranged at the corners of the square or rectangular base

transfer loads of heavy structure plus any imposed loads via the frame structure members to a suitable lower ground

concrete Plain: mixture of cement, fine & coarse aggregate & water

Increases its strength during curing / hardening period

Portland cement is used – 28days

Nominal max sizes of aggregates: 40, 20, 14 and 10mm; 5mm is for precast products

Grade 7 & 10 - plain unreinforced concrete

Grade 15 & 30 – RC with lightweight aggregates

Grade 25 – RC with dense aggregates

Grade 30 to 50 – pre-stressed concrete

Eg: strength of Grade 10 = 10.0 N/mm2

Reinforcement Requirements:

Capable of achieving tensile strength without any undue strain

A material can be easily bent to any required shape

Surface must be capable of developing adequate bond between the concrete & reinforcement

Reasonable cost & acceptable to overall design concept

steel in the form of bars

mild steel (R) & high yield (T)

strength: 250 N/mm2 & 460 N/mm2

nominal sizes: 6, 8, 10, 12, 16, 20, 25, 32mm

Equipment

Bar bending machine

Equipment – cut manually

Fabric reinforcement Structural members that require only small area of

reinforcement can be reinforced by steel fabric, which can be supplied by sheets / rolls

Factory-made by welding

Sheets: 4800mm x 2400mm

Rolls: 48.00m & 72.00m with a common width of 2.40m

Total cross sectional area of main bars in mm2

Formwork A mould / box into which wet concrete can be poured

so that it will flow & finally set to the inner profile of the box

Requirements:

Strong enough to support the load of wet concrete

Must be accurately set out

Have grout-tight joints – grout leakage can cause honeycombing of the surface

Designed to be the max size that can be easily handled by hand & mechanical lifting device

Can be easily fixed using ?

Moisture content btw 15 – 20%

Formwork

Steps to build a RC framed building Setting out

RC piling (if applicable)

Pile cap / footing

Stump / ground beam

GF slab

Ground column

1st floor slab & beam

1st floor column

Roof beam

RC staircase

Timber roof trusses

Brickwork

Plumbing & sanitary

Roof tiles & flashing

Ceiling

Wall finishes

Floor finishes

Staircase finishes

Door leaves & windows

Ironmongeries

Electrical fittings

External & infrastructure work

Concrete framed

building

stumps

Ground beams

Ground floor slab

Ground floor

columns

1st floor beam &

slabs

1st floor column

Roof beam

STUMP A short column constructed on top of the pad

foundation / pile cap to support ground beam & column above

to transfer the load of a building onto the pad foundation / pile cap

to raise ground beam & ground floor slab to the required height above GL

Basic elements:

Reinforcement

Formwork

concrete

Beams supporting walls, joists, etc., at or near ground level,

itself either resting directly upon the ground or supported at both ends by piers.

used in situations where foundation walls may not be achievable

Vary in their complexity of design & reinforcement depends on loading

erected over columns or piers taken into the soil

Transfer their loadings to columns

When erecting them, the piers must be already cast in the ground

Beams Clearing the ground

Blinding layer

reinforcements are then tied and bent separately; carried and laid over the columns and blinding

Formwork erected to sides

concrete is prepared and poured

Columns Constructed from either plain concrete (1:3:6) /

reinforced concrete (1:2:4)

vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below

to support beams or arches on which the upper parts of walls or ceilings rest

Columns must be properly located, and the choice of a steel beam or wood beams

Process

Superstructure

Tie up all rings around and into vertical steel bars according to design.

Fix form work of required size with vertical steel bars.

Lay cement concrete

Foundation

Excavation Steel bar, formwork, concrete to

footing

Link tied to main bar Adding spacer block

lapping Wood bracing

Sometimes, we use steel formwork

Group Activity: Compare the advantages of timber & steel formwork