Friday, November 15, 2019

West Marsh Structure 2: Update #4 -- Concrete Floor in Place

Structure 2, featuring a completed cap (and dry ground -- a rare occurrence over the last month) 

While progress has been steady on Structure 2, our new connection between the two major management units on our West Marsh, much of the last month hasn't been terribly photogenic. That's partly due to where we are in the construction process (several tedious steps that do not translate to big visual advances), and partly due to more than our fair share of cold, wet weather -- at least for early to mid-November.

Rebar in place on the bottom of the new structure
just prior to the arrival of concrete
The fabrication and placement of the rebar reinforcement structure that will serve as the backbone to the floor of the flume is case and point. Layout, wire wrapping, and welding are each methodical and inherently slow. But the devil's in these details in terms of long-term durability and structure longevity.

The guys were really got a workout slopping through the shin-high muck as they welded all the metal sheer studs and rebar lattice underlayment into place. Rainy days during the last week of October coupled with sensitivity for the start of the latter half of duck season (which officially opened on November 9th) presented an anticipated challenge in terms of finding the right window for the next major step in this process: the concrete pour for the structure's floor.

We really wanted to "rest" the marsh the last couple days before hunting resumed (meaning keep the construction crew -- and everyone else -- out of the marsh to allow the birds to acclimate and find regular refuge). We fortunately got the right weather window, and the pour went off without a hitch last Tuesday.

Slow and steady proved to be the name of the game when it came to prepping for the first of two concrete pours;
the structure's floor was poured last week and the bridge crossing is set for next week

Mixer truck in position to feed the concrete hopper

The concrete hopper being loaded prior to positioning within the structure's flume

Positioning of the concrete hopper once loaded

Field testing of wet concrete prior to placement

Once the wet concrete was roughly placed in the flume via the concrete hopper, it was floated and continuously shot
to confirm the targeted finish elevation

A finished view down the ~40' x 4.5' flume as the fresh concrete continues to cure

Fall turned to winter early this week when rain quickly transitioned to snow and overnight temperatures plummeted into the single digits. Afternoon highs barely got above freezing this week, insulated by the first accumulating snow (3-4") of the season. The marsh completely froze by Tuesday and we may have as much as 2-3" of ice cover in spots as of today.

That said progress continued at the project site this week. The guts of the structure (screw gate, aluminum stop logs, carp screen, etc.) have been delivered on site. Good headway was made on the fabrication to receive all these components, and if all goes well (and weather cooperates), the concrete crossing will be poured next week. If the marsh gods shine favorably down upon us, we could be operational by Thanksgiving. Call me a skeptic, but based on recent weather trends, I'm betting on early to mid-December. We'll see.