Week 8C: Concrete 101

This week we poured and built the lower retaining wall of the house. Since the project sits on a hillside, we needed to create a pad for the lowest floor. Things are moving along now and we’re on schedule for finishing up the foundations prior to my departure to Berlin. The photo above illustrates how difficult it is to stage work on the site. Garcia Masonry has built a deck for their supplies in order to make staging easier.

The grout must be tested to ensure that the concrete in the masonry walls is of the appropriate strength (2500 psi). It’s rare that the concrete would come in under it’s required strength, but occasionally site conditions, too much moisture, and fluctuations in temperature cause the concrete to cure unevenly. During the pour, Shorty, our concrete pump operator fills the test cans and boxes for the deputy so that we have accurate samples coming straight out of the truck.
Because the concrete for the grade beams is 3000 psi we are required to have it tested to ensure it reaches it’s maximum strength. Test cylinders are cast and then allowed to cure for the maximum 28 days. They are then taken to a lab and put through a pressure test to see if the concrete holds up.