Tuesday, November 20, 2018

Project Engineers' Guide: Construction Methodology

Fieldwork No. 21


Good Morning Class. We have installed 4 column formwork today. The method of construction of aligning the formwork is to fix one side first. We install scaffolding to brace and support this panel. We install the opposite panel next and the third side. We then brace the steel bars to align with the formwork. The concrete cover is 25mm on all sides. We will also embed dowels (abang) to connect the horizontal bars of the CHB wall.

We will offset from Gridline 1 to align horizontally while vertically you use the plumb bob.


Give this dowel drawing to the Steelman and say give me 300mm and 35mm on the bend. I have never met a Steelman who cannot measure.

Fieldwork No. 22


Good Morning Class. Check the dowel size. It is 45mm on the bend. The dowel also serves as a spacer. My Japanese Supervisor taught me this method so as not to damage the formwork. I modified his L-shape into this U-shape so that the Vibrator can fit inside the column..

We will pour 4 columns today. 8 workers will do the concrete pouring while the Steelman and Helper fabricates. The scaffolding of good lumber will brace and support the column up to 2 meters. Another scaffolding on one side will be H-Frames with ladders and platforms. Make sure they are stable. One worker is the top, one at middle ground and one on level ground. One will operate the 2-Bagger Cement Mixer while 4 workers carry the buckets of wet concrete. Provide a ladder at the opposite end. Use the vibrator at 5 buckets interval. Poke the corners and sides with a 12mm dia meter steel bar.

I calculated one column will need 2 cement bags. In the ratio of 1:1.5:3 (4000 psi), the workers will use the cement sack as measuring tool. That would be 3 bags of sand and 6 bags of gravel.

Fieldwork No. 23


Good Morning Class. Yesterday we have poured concrete on 4 columns. We have installed 5 column formwork today. Tomorrow we pour concrete again. My Carpenter has learned the use of the Nail Gun. It is better than hammering. But the fabricated panels have bolts and nuts so they can be detached easily. We would remove the formwork after 5 days. It can be a hassle when the concrete has hardened.

Tools and equipment are necessary to make the work more accurate and faster. The Flatbed Truck can transport materials such as cement, sand, gravel, steel bars, tools, equipment and manpower.

When you order Ready-Mix Concrete from the Batching Plant, consider the location and terrain the Cement Truck has to travel. Its capacity is 6 cubic meters but since it is heavy we order less 5, 4 and 3. Say you blocked out for 10 cubic meters. That would be two truck loads of RMC. Estimate how long you gonna pour the first truck load of 5 meters and advise the Batching Plant the interval they gonna send the second truck load.

Fieldwork No. 24


Good Morning Class. We poured concrete in 4 columns today. Now and then i will use construction terms whether in English or Filipino and explain it later okay. Block Out means the area prepared for concrete pouring. When you install formwork you block out the structural member. Say our beam or slab is blocked out at this point.

Fieldwork No. 25


Good Morning Class. We installed 3 column formwork today. The steps in installing these panels are aligning one side then the opposite side then the third side. Tie the dowels at the specified height of the CHB horizontal bars to reinforce tension or pull. When the concrete has hardened you carve (sinsil) the dowel from the casted column.

The formwork will warp and will be dented upon removal that is why the Carpenter will repair it. When installing warped formwork you have to brace the left and the right side of the panel, where it is warped, to make it square.

1 comment:

  1. This has been very insightful, thank you. We are a ready mix concrete company. God bless!

    ReplyDelete