BT 5 -02.1 Alternative Concrete Construction Systems

Uni Span Floor System

• Made up of a 75mm prestressed concrete slab.

• With in situ structural topping up to 8m

• Solid completed floor reduces inter-story noise vibration

Interspan Floor slab

• 200 mm wide precast prestressed concrete ribs at generally 900mm centers

• 75 mm in situ concrete topping + mesh reinforcing

• Rib depth varies with project load/span requirements

Tilt-Up Wall System

Precast concrete walls made us as large panels, then raised and placed with crane assistance.

T-Beams and L-Beams

Reinforced concrete floor system placed monolithically with supporting beams forming typical T and L cross-sections.

Channel Beam

Utilizing a C-channel usually with reinforced concrete or metal decking with reinforced concrete.

Flat Plate System

• Reinforced concrete frame system with uniform thickness, supported directly over columns or load-bearing walls

• Uniform thk.

• Flat soffit

• No beams

• Ordinary economical span: 6m but increased to 8 to 12m

• Not for heavy loads

Ribbed or Waffle Slab

• Parallel reinforced concrete T-beams framing into reinforced-concrete girders.

  • One Way Ribbed Slab

  • Two Way Ribbed Slab

One-Way Ribbed Slab

Small reinforced concrete T-beams/joists connected with girders

Two-Way Ribbed Slab

Orthogonal ribbing creates two-way configuration for large spans.

Lift Slab System

Also called Youtz-Slick Method.

• Floor or roof slabs are cast on top of the previous slab and raised using hydraulic jacks

hydraulic jacks

Lift Slab System — Floor or roof slabs are cast on top of the previous slab and raised using ________

Composite Construction

Construction using more than one material to create a structurally sound bldg. system.

Span Stress Floor System

• Uses span-stress prestress T-Joists with filler blocks or collapsible steel forms/plywood forms

  • Light yet capable of heavy loads and long spans

  • Span:3m to 9m

C-Joist Slab

Precast, prestressed concrete product used for floor and roof slab systems.

• Concrete product stated at 5,500 psi.

• Supporting suspended flooring and forming part of a slab

Hollow Core Slab

• Precast concrete slab with tubular voids extending the full length

  • Dimensions: Typically 120 cm wide, standard thk. 15-50 cm

Single T-Slab

Precast concrete deck with one stiffening rib integrally cast

Double T-slab

Used for parking structures, roofs and floors where long spans and/or heavy loads are required

Slip Form System

An advanced construction method where concrete is poured continuously into a moving formwork that rises steadily upward or moves forward as the concrete sets

Jump Form System

A self-supporting modular system that "jumps" or climbs upward level by level to build vertical concrete structures like high-rise core walls and elevator shafts

Box Girders

• A box/tubular girder forms an enclosed tube with multiple walls

  • Better resistance to torsion than an I-Beam

  • Multiple webs can carry more load than an I-beam of equal height

Uniform thickness slab directly supported by column/walls

What is the main structural feature of a flat plate system?

Reduce Dead Load

What is the main purpose of the voids in two-way waffle slab?

Slip = continuous vs Jump = step by step

What is the key difference between slip form and jump form?