Let us return to the last couple of weeks of our workshop to talk about preparation and the process of pouring concrete.
During the third week of our workshop we started to prepare the place for a future slab: smoothing the surface, framing the form, and making a proper ground level. On the day of the pour we got up very early to mix the concrete mass. David explained to us what are the proportions and how the process should be done.
We started with putting cement into the mixer, then gravel, sand and water. And in some minutes, when the mass became homogeneous David showed us how to make a slump test. We put some concrete into a special cone and then took the cone off, and measured a height of concrete mass. It was good enough for pouring so Jeff could drive the concrete mixer down to the Construction Site.
On the Construction Site everything was ready for casting. We were divided into small groups, so some of us helped with the concrete mixer, others with smoothing the concrete and checking the proper position of wired mesh in the concrete mass, a couple of people went with a big beam along the frame to make the surface of a slab flat enough. When the concrete mass was poured into the frame and had set a little; we started finishing the surface with trowels.
The last part was spraying the slab with a special liquid to seal moisture into the concrete. The work was completely done before lunch and after that we watched two movies made by ACI about mixers, slump tests and casting.
It was very interesting and important for us to try something by hand, to see the whole process, to understand how material works, because most of us know construction just in theory. And the practical knowledge we can’t get at the universities.