WAFFLE SLAB

SECTION DETAIL

JOINTS

Central drop panel assembly with steel column.

Four channel sections will be placed, according to the Technical Documentation, centered about the floor depth.

The anchorage shall be incorporated to the support in the shop.

The sections will be welded to each other and to the support all around the contact perimeter, with a 5/16 in. thick weld.

At the joint, the interrupted channel will have a continuous cover plate of steel with a total area matching that of the top flange of the section, welded all around with a 3/16 in. thick weld.

A spiral of W8 flat wire conforming to ASTM A 82, with a 4 in. spacing, shall be placed in both arms of the steel anchorage.

The recommended crosspieces are for building floors with conventional live loads and reasonably balanced spans. In all other cases an individual study is required.

Adjacent drop panel assembly with steel column.

Four channel sections will be placed, according to the Technical Documentation, centered about the floor depth.

The anchorage shall be incorporated to the support in the shop.

The sections will be welded to each other and to the support all around the contact perimeter, with a 5/16 in. thick weld.

At the joint, the interrupted channel will have a continuous cover plate of steel with a total area matching that of the top flange of the section, welded all around with a 3/16 in. thick weld.

A spiral of W8 flat wire conforming to ASTM A 82, with a 4 in. spacing, shall be placed in both arms of the steel anchorage.

The recommended crosspieces are for building floors with conventional live loads and reasonably balanced spans. In all other cases an individual study is required

The embedded beam orthogonal to the edge, which makes up one arm of the crosspiece beams in central drop panels, may carry stirrups depending on the magnitude of the punching shear, etc.

The crosspieces made up of 2#5+2#4 may carry stirrups, depending on the magnitude of the punching shear. The size of the stirrups must be defined for each case. The stirrups may be simple closed elements that help support the top layers of reinforcement, although this is generally done by the shrinkage steel resting on the lost filler blocks. In the case of removable formwork, such reinforcement must rest on chairs to provide the proper concrete cover.

The indicated reinforcement have a range of application in typical residential projects; in other jobs it must be adapted to the particular conditions.

http://constructiondetails.us.cype.com/EAM507.html

Construction of Waffle Raft Slab System:

1. Ensure building site is level and all plumbing pipes are fixed in place as per plan.

2. Spread a layer of sand or metal dust approximately 50 mm thick over building area and screed level. Place 200µm plastic sheeting and tape laps.

3. Set up formwork, set out Waffle Raft Pods in a grid pattern using multispacers provided which form all beams.

4. Cut the Waffle Raft Pods to fit around plumbing pipes etc. using sharp handsaw or powersaw. Place reinforcing bars in multispacers positioned between void formers.

5. Place steel mesh on top of Waffle Raft Pods and chair steel mesh at a rate of 4 bar chairs per Waffle Raft Pod.

6. Pour concrete, part fill the ribs to hold the Waffle Raft Pod in position before pouring 85 mm thick slab with 25 mm minimum cover over reinforcing mesh (or as per engineers instructions).

http://www.ab.deakin.edu.au/online/vgallery/2004/srt251/team10/Site%20Pages/Structural%20Systems/waffleslab.html

What is WAFFLE SLAB ?

a two-way concrete slab reinforced by ribs in two directions.

formed of pre-fabricated, reusable metal or fiberglass forms which allow construction to proceed faster than with custom wood forms.

used in airports, parking garages, commercial and industrial buildings, bridges, residences and other structures requiring extra stability.

ADVANTAGES :

Its complexity typically renders a less economical than other system with comparable span and load carrying capability.

Provides support for heavier loads at slightly longer span.

Faster to construct than wood forms.

DISADVANTAGES :

Requires special or proprietary form work.

Greater floor-to-floor height.

Large vertical penetrations are more difficult to handle.

PIPE