It Never Rains in California
It was raining around the Silicon Valley but not on Via Sereno.
We were humming Albert Hammond’s song all day, hoping it wouldn’t start pouring.
Starting the Day
GraniteRock supplied our 10 truckloads of concrete today, which was 50% slag, and Dees-Hennessy performed the actual shotcrete (using their equipment and mobile air compressor).

Using compressed air, the concrete is pumped through a hose to the nozzleman, who shoots the shotcrete on the reinforcing steel (rebar) mat.
We started in the stair well, which was narrow and needed to be shotcreted on three sides. This took some time since it was cramped and congested.

There are several workers inside the stair well, finishing the exposed concrete walls that will be seen as people use the stair well. Note the independent inspector observing the procedures and taking notes.

The nozzleman, and his helper, have a difficult and noisy job as they shoot the concrete on the vertical face, being careful not to leave any voids, or 'shadows', behind the rebar while being efficient and not using an excessive amount of shotcrete.

Howard Bell, from the City of Monte Sereno, on the left, with Gary Stafford and a trainee on the right, both with HP Inspections.
The open and straight walls, on the north and west side of our excavation, were completed quickly.

For redundancy, Dees-Hennessy always has a second air compressor standing by to ensure they will not be responsible for delays due to mechanical failure of their equipment.

Sample of shotcrete to verify that, through destructive testing, the compressive strength meets or exceeds the design specifications.
Successful Shotcrete
The entire team on the job site was very happy as we reached our objective, which was to complete the perimeter shotcrete retaining walls today. After we started, everyone knew that the weather could get worse and working in the rain would be extremely unpleasant. Even though the weather cooperated, it was a long and tiring day for everyone. With rain, it would be simply miserable.
The weather held and we were fine.
Two Problems
There were two problems today.
The first was the sixth load of concrete. The previous load in the truck was not completely emptied from the mixer and large pieces of concrete were causing blockages of the shotcrete hose. After identifying the problem, we sent the offending truck back.
The second problem was a lengthy delay before truckload #8 arrived. After emptying truckload #7, we waited more than 45 minutes for truckload #8 to arrive. This caused everyone’s day to be longer. Stress levels were high as the clouds were moving around and the winds had picked up. Standing idle in fine weather causes stress knowing that progress is not being made and, when the truck arrives, it could be raining.
On a very, very positive note, the weather held all day. Although it was raining throughout the Silicon Valley, we did not feel a drop of rain on Via Sereno. In fact, the sun came out a couple times.
We continued to hum. And smile from ear-to-ear!
Tags: Dees-Hennessy, Eichler, Graniterock, Shotcrete, slag mixture









