Day 28: Pouring the first wall lift

Las Animas Concrete and Pacific Coast Concrete Pumping were back again today. This time concrete grout was pumped to fill the network of horizontal and vertical cells in the APEX blocks. The grout is inspected for slump to be sure it is not too thin or too thick. Here is a vid of Mark, the inspector from PSI, performing the slump test.

We passed with a slump of 8 inches, the thinnest mix allowed per structural engineering. A thin mix is desirable because it penetrates hard to reach areas more easily than a thick mix. Mark verified proper rebar placement before pumping. He also verified that grout filled the cells by poking a ¼” diameter rod through the APEX block skin at the bottom course. The rod came out wet with concrete indicating proper fill. Finally, Mark took samples of the grout which will be tested for compressive strength over the next several weeks.

Here is a pic of the pumping crew in action: from left to right, Trevor, Mark, Georg, Todd, Joshua & Justin.

The tasks were:

• Hold the hose over a cell with minimum grout spillage while concrete is shooting out at about 3 feet per second.
• Move the vertical rebars up and down in the cells to help consolidate the grout.
• Clean any excess grout off the top of the blocks.
• Center the vertical rebar in the cell after consolidation.
• Repeat for 100 cells.

Stapling plugs after filling cells under the window openings.


Marty strikes a pose in front of some extra grout used as fill against the east wall. This grout will help facilitate water drainage at this underground wall.

A beam support bracket set in place.

Rafael has a little fun while monitoring the hose.

We finished in just a few hours with no blowouts. We have the rest of the afternoon off, wohoo!

Pastel Green comment for today:
The Portland cement ingredient in concrete has high embodied energy which typically classifies a product as non-green. However, the APEX block cells minimize the amount of concrete needed to make an acceptable structure compared to a typical Insulated Concrete Form (ICF). Additionally, the house is expected to last hundreds of years making the use of concrete more tolerable from a life cycle analysis standpoint.

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