Sunday, January 15, 2012

Actual construction begins

Until now the work has been to dig holes, pile dirt and make lots of mess. Seems like we have been going backwards, although to move forward you often find yourself appearing to be moving backwards. Well, the time has come to actually see forward progress.
Rebar work has been going on at a steady pace. The rebar was delivered by truck to within 500 meters of the site and had to be hand carried from there to the site.
All rebar cutting and bending is done on site and most of the cutting is by hack saw. Once cut and bent it is tied together to form the columns. The foundation rebar is tied in place in the foundation holes.

This is the first rebar installed in the foundation. The upright pieces are for the columns that will support the building.
It is the responsibility of the design engineers and myself to check the rebar and forms to insure the installation complies with the design specification, and then to sign off on this work once the rebar is tied and the forms are in place.
Then we can move to pouring the concrete.

Concrete is also mixed on site with a one bag mixer. That means they put in one bag of cement, two buckets, like the one seen here, of aggregate, and 1 1/2 buckets of sand with enough water to maintain a certain wetness called slump.

The slurry is then dumped into wheelbarrows, about 3 to 3 /12 wheelbarrows per mixer load depending on how full they make the wheelbarrow, and hauled to the pour hole and dumped. The whole process is quite labour intensive but moves along quite smoothly and quickly.

Vibrators are used to insure full coverage around the edges and around the rebar. The concrete gets a rough trowel finish and then left to cure. The forms are stripped away the following day and the concrete is checked for any honey combing which is patched immediately should any be found. At present we have completed the pouring of all the footings on one side of the building. We have also poured eleven columns, somewhere between 25 - 33% of columns poured, and all this work is what is going to be beneath the ground floor.

The above shot is taken from the roof or our office building to give you a general overview of the site. The shot to the right shows the completed concrete pour of the foundation pads and columns.

We have  been on site working for seven weeks now with reasonably good progress. The site is looking much different each week. Soon we will begin back filling the foundation holes. That will provide us with much needed clear space for materials and work clear work areas as the site is presently very congested.