AXA / Grocon Site

I visited the AXA project which is being constructed by Grocon Constructors.
The top floor where the plant room is located is still under construction. The services on the roof are to be housed in a portal frame type structure. Concrete slabs where being installed as well as the structural elements for the frame.

Concrete is being poured to form a slab. In this photo the void barrier can be seen as well as the reinforment which is sitting on reinforment chairs. The concrete is currently beng placed and will be poured to the level of the surrounding formwork. The process of installing the slab is in this order.

This slab itself is actually a floating slab and has metal casting mounts with rubber inside (the red mounts in photo). Bolts are screwed through the metal casting into the rubber mount which then raises the slab.

Services such as generators, chillers, pumps are positioned on top of the floating floor. Having the floor raised on rubber mounts eliminates sound travelling through the building. Floating floors are used when acousitc solutions to vibration are required.

Here the slab is still being poured. Shovels are used to move the concrete around and a worker uses a piece of timber to smooth out the concrete.

The beam of this structure has cleats and brackets welded to it. These have been done off-site during the fabrication process. Other structural elements will be bolted to these brackets.

This UC column is welded to a base plate which is then fixed to a pad. Around this is 'ableflex' which is a type of material used to create isolation and construction joints. The joint created reduces/eliminates cracking. The bolts which are use to fix the column to the pad have been cast-in and are referred to as hold-down bolts.

A purlin is shown which is fixed to the top of the rafters with the use of cleats. The cleats are welded to the rafters and bolted to the purlins. Safety mesh is placed on top of the purlins.

Between the purlins are braces which help when lateral forces are applied to the roof structure.

Rods are used in the roofing structure to help make it secure when lateral forces are applied.

Where the rafter is joined a bolted splice is used. A web cleat is used to join the member.

The column and beam are joined to each other using bolts. The bolts are inserted through the plate that has been welded to the column and then through the flange of the beam.

The gap between the base plate and pad base is filled with grout. The grout is made on site and is installed usig a hand trowel.

Hold-down bolts are cast in the concrete. They pretrude long enough to take into account for the space between the concrete and base plate, the thickness of the base plate and then thickness of the bolts.

Between the base plate and the pad (plinth in this case) is a space due to the use of packers (small peices of metal used to raise the column of the pad/plinth). Using packers allows the column to to be tightened more on each bolt to level and plumb them up. Without the use of packers it would be very difficult to plumb and level columns.

Structural members are lifted with the use of a crane. Workers use scissor lifts to help position the members so that brackets and holes line up ready to be bolted together.

The steel structure which have been fabricated can be erected by the fabricators steel workers or the building may decide to have his own workers erect the structure.