N6NZ
Amateur Radio Station N6NZ - Pouring Tower Bases
What do you do when the backhoe is half way to spec depth and hits solid rock that, in the opinion of the backhoe operator, "goes half way to China"? The silly thing to do is to spend $1200 blasting it out so that you can fill the hole up again with concrete. Smarter is to drill into the rock and use rock epoxy to cement in some rebar. The rebar is just visible in this photo, to the left of "the shadow".
Concrete pumps are truly slick machines! Here is the business end. This one pumps through a two inch hose.
Fill'er up! This is a different tower, with a more "traditional" hole. Because the soil is rocky, the hole is somewhat over-dug from picking out boulders. The spec calls for 7.5 yards. This hole consumed probably 15 or 16 yards. That is the bottom section of a Trylon tower that will eventually be 64 feet tall. You can just make out the rebar cage around the stub legs.
Back to the tower that is rebar-ed into the rock. The base is being topped off. You can see a stream of concrete coming out of the hose.