10. Column from bricks and concrete cube

Now this might seem like a crazy idea but we have an abundance of standard size concrete cubes that was left behind formerly meant for testing. So I’ve decided that it was consuming too much space in the lab that it simply had to go. Instead of throwing them away I’ve instructed the students to make a column core out of cubes and bricks on the external facade of the column.

Early stage of brick placement

Fixing the height of the cubes

We first had to level the cubes to make sure they are the same height with the other completed concrete beam (again water level was applied).Once we have reached the desired height we placed a cut out plywood (same size as the final column) and hung some plum bob at each corner to have a reference line for the placement of the bricks.

Placing the plywood & lines

It is done

(Bricks & Cube Column Song- Iwanna Change)

9. Completed Beam

After 7 days we then strip the formwork to reveal our first beam. Again we had such an adrenaline rush because this was our first. This is the moment that we all had been waiting for. It’s even more intense than the column; if the beam collapses we would have to build everything again and go back to the drawing board.

Opening the formwork

Completed beam

But lady luck was on our side and based on the reinforcement that we placed internally it actually could hold its shape. It was a glorious achievement and we definitely deserve a pat on our backs!

We were so confident with the beam that the students actually sit on it to test its strength.

Adding load to the beam

After 28 days

FUNNY ANSWERS

8. Beam concreting

Shortly after the placement of formwork, the students then had to go through the most tasking part that is to do concreting. Students divided themselves into 2 groups one is in charge of mixing the concrete using a drum mixer while the others would do a lot of compaction and tampering of the fresh concrete.

The concrete mix ratio was 1:2:2 and water cement ratio of 0.5 is used to increase its workability.Transportation and pouring was done by wheelbarrows and buckets while tampering was done by rods and solid timber blocks.

                                           (Concreting process.Song By Jack Jonson)

During compaction a large amount of water could be seen trickling through the gaps that were not water tight. We found out later that this will cause some major problems like segregation where you could see the exposed aggregates and stones.

Water escaping from gaps

To prevent this from happening again, during the construction of our next formwork I advised them to place some timber filler in any gaps or openings. The second and the following beams were 100 times better that our first attempt.

Students then placed a layer of concrete about 150 mm before embedding the rebars. This process was repeated and finished off with a trowel.

Finished surface

View from a distance

7. Formwork erection

Soon after completion of the formwork, the students then had to make Y bracing for the soffit of the beam. The bracing was made from once again recycled metal( used to be part of a lecture hall bench) and we did spot welding to crate the Y shape that was used in the support system.

Y-Brace

After placing the formwork in its actual position the students then had to make adjustment so that the formwork was vertically straight and leveled on all sides. Water level (water in a translucent tube) and spirit level was used to achieve this goal.Once the level was obtained we wedged the Y bracing under it to make sure that it dosent move any more.

Testing and adjusting

Placing the First bracing

Quote of the day  "Without order nothing can exist - without chaos nothing can evolve."

6.Formwork for Beams

Urghhh! The dreaded beam! Will it sag? Will it stand? Will someone help us! Well it was time to sink or swim. Based on the span of the beam we managed to gather some recycled plywood and start constructing the mould for our beam. This time the team was more than willing to spend some time to reinforce the side formwork and the soffit of the formwork as you can see in the picture.

side support

soffit support

Some might laugh at the ridiculous amount of timber bracing and support but bear in mind that the plywood was thin and was recycled! It doesn’t have the durability of new plywood but when the going gets tough the tough would do anything to get GOING!

side support

completed beam formwork

        (some short clips & song from discovery)

5.Removing the formwork

After 7 days the concrete for the column has set and is hard enough to support its own weight. I must say that it was an intense moment for my students & me for we all share the same fear of having a column that was perforated and looked like a cheese instead of a solid structure.

But after gathering their confidence and remembering the amount of compacting they have put into making the column they finally strip the formwork open and there it was standing proudly and majestically with minor honeycombs!

Formwork being strip

After some touching up of the surface

Not long down the week we have constructed our second column with better result and little difficulty because of our previous experience.They say that practice makes perfect and it is proven true!

Our second column

4.Formwork for column

After the students decided on the dimensions of the column, obviously the next step is to make a mould which is the formwork. The formwork was made from plywood for the sides and timber blocks for the external bracing.

During their first attempt the students neglected the importance of the external support because it was just too much work but during the placement of concrete the pressure from the wet concrete burst the base of the formwork that requires it to be redone.

First attempt not much external bracing

The second attempt was a success and it was a matter of learning through their mistakes.

Making sure the formwork is plumb by shoring

More external support

Finally the students placed the wet concrete and at the same time tampering and compacting was done to minimise the honeycombs.

Student using a wooden pole for compaction