Shooting the Shotcrete Test Panel
Shooting the shotcrete test panel and three compression test samples took 12 minutes to complete.
Setting up the test took less than 30 minutes.
Bill Brown’s team had the test panel in place near the front of the site and the shotcrete nozzlemen and pumper (with air compressor) were in position and ready. The Graniterock truck, loaded with three yards of mix, arrived at 8:26 am. Then, the special inspector from HP Inspections, Gary Stafford, arrived right on time at 8:30 am. We had a quick meeting to coordinate the test.
One of the special inspector’s key activities was to review the reinforcing steel (rebar) placement in the test panel and identify where the densest area of rebar is located so he can specify where the core samples will be taken.
Shooting Shotcrete into the Test Panel
Each nozzleman had to shoot the shotcrete into the test panel, with the same pump operator and the same equipment that will be used when the retaining walls are completed.
The test panel required the full setup on the street. The only difference between the test panel and the retaining walls will be the number of Graniterock trucks delivering concrete.
With concrete, the ‘slump’ is a key test to ensure the concrete mixture is delivered as specified.
While the test panels will measure any voids in the shotcrete retaining walls, we also used the same shotcrete mix for three plugs, for destructive testing of the compressive strength of the concrete.
Completing the Shotcrete Test Panels and Plugs
With the test panel and plugs completed, Bill and Gary completed and signed the documention regarding the test procedures and observations.
Having completed inspecting the shooting of the shotcrete and identifying the locations where the core samples will taken, Bryan and Gary left the project site at 9:50 am to go to the City of Monte Sereno so Gary could present his qualifications to the Building Official. That was completed by 10:05 am.
Completed Shotcrete Test Panel and Plugs
The procedures went quite well today. Now, the shotcrete test panel and plugs need to cure and gain compressive strength before core samples are taken.