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