Monday, July 8, 2013

More Concrete, More Night Work and More Heat

I took three more visiting grandchildren to the site this afternoon.  It was ninety-three degrees, so we just made a quick pass around the block.  They were good sports to come with me, for sure.
We got to see Mr. Crane at work.  He was moving lights around, I suspect to prepare for the next shift which will work until 2 a.m.
We watched a pour and I had fun explaining the concrete pump.
It looks like the exterior wall of the south porch was poured.  A stairwell from the lowest level of the basement to first basement level will be here. 
Only after I returned home did I see in the photo that concrete was poured outside the foundation wall on the south side, just as it was poured last week on the north side. 
This exterior concrete is called flowable fill.  In this setting, it is better than dirt.  My visiting engineer-son explained to me that it wants to stack on itself and not spread out.  This is a plus because it doesn't put any pressure on the foundation walls.  This type of fill is easy to work with and the Lego men can dig in it if they need to.
I watched workmen enter and exit the basement of the tabernacle through the elevator shaft at the base of the northeast tower.  Handy, I'm sure.
I tried to peek inside the basement again.  I saw these orange lotus plants before a big slab pour in May.  I would guess they are getting ready for another pour, except I was told that the next slab pour won't happen until the piers have been cut away, and that won't happen until the upper level of the foundation walls has been poured and the weight of the tabernacle is transferred from the I-beams.
We stopped for a look at the west lot before racing back to the water in our car.  It looks like the forms around the slab on the right are complete.  Maybe the concrete pump will be back tomorrow.


David Smith said...

Let's see now - Wikipedia says concrete has a density of about 2400kg/m^3, or 2.4 x that of water. I recall that atmospheric pressure of 14.7 psi is equivalent to a 32 ft column of water. Taking a wild guess that the concrete pump is raising its fluid by 64 ft, that works out to a pressure of about 2.4 x 14.7 x 2 = 70 psi. I was just curious. How's that for mixing units?

Julie Markham said...

I'll see what the engineers around here have to say about your math and get back to you...