Good Morning Class. We continue our column formwork installation today. We have a combination of wood, timber and pipe scaffolding. The wood bracing will push and pull the left side and the right side of the panel to get the alignment. The H-frame and the A-frame are pipe scaffolding systems. It resembles the letters H and A. They are anchored to ground by adjustable jacks - metal plates with threads to adjust verticality. To make the scaffolding stable drive timber anchors and pipe bracing with c-clamps. The pipe frames are joined vertically by pipe connectors. The scaffolding are attached with steel platforms and ladders.
Fieldwork No. 27
Good Morning Class. We poured concrete on 4 columns today. Concrete hardens in one hour so you pour concrete within that duration. The workers know when its pouring time that breaks will be irregular as the concrete pouring takes precedence. They eat after the batch of concrete is poured.
Let us talk about concrete pouring preparation. You inspect the columns with a flashlight to see if there are debris on the bottom. Fish it out. Pour grout on the surfaces. Grout is a mixture of water and cement and is poured so that it clogs the openings since grout hardens. You can also spray waterjet and blowers to remove debris. When the surface has moisture it minimizes water loss on the wet concrete that prevents honeycombs or hollow spaces inside.
Check the supports and braces - push, pull, kick them to make sure they are stable.
Fieldwork No. 28
Good Morning Class. We poured 4 concrete columns today. Concrete is designed for compressive forces okay so that is why we derive the shear diagram. Steel is designed for tensile forces okay that is why we derive the bending moment diagram. Concrete shears. Concrete does not bend. Steel bends. Steel does not shear by loads. That is why i am pondering my my stair design.
Fieldwork No. 29
Good Morning Class. We had no work on Nov. 30 as we observe holidays. Last Saturday we poured concrete on two columns. After we have finished the first lift of the columns we pour concrete on the wall footing.
We now canvass the materials we are going to use. We cover the grade slab with Polyethylene Sheet. It is necessary so we minimize water loss and wastage of concrete as we pour into a gravel bedding.
Fieldwork No. 30
Good Morning Class. We installed column formwork today. I procured Concrete Hollow Blocks (CHB) so blocklaying follows after the wall footing is poured. Note that the shear wall indicated will have a special formwork. These blocks are 1000 psi or less but the mortar (palaman) to fill the hollows should be 2000 psi. That would be cement sand gravel ratio of 1:3:6. Our mortar would be 1 part cement and 9 parts sand (3+6). It is not load bearing meaning they are not designed to resist the forces. The suspended slab, the beam, the column and the footing bears the loads. The grade slab 3000psi is independent but it is designed for shear. Say when you drop a heavy equipment or tool, the floor slab should not break.
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