This project involved a field campaign and subsequent
data analysis for the Route 30 bridge over the South
Chuctanunda Creek in Montgomery County, NY. The
two purposes of this work were: 1) to make more
detailed measurements of the bridge environment than
we have done in the past to better understand the
energy budget of a curing concrete bridge and 2) to
provide atmospheric boundary conditions to a model
of curing concrete.
New measurements included direct sensible and latent
heat flux below the bridge, top surface concrete heat
flux with heat plates, and air temperatures between the
beams. The amount of heat that was conducted toward
the top surface during the peak internal temperatures
was estimated to be around 390 Wn-2. This heat was
removed most efficiently by the runoff water heat flux
(150Wm-1) while the latent heat flux and net radiation
each accounted for about 100Wm-2. Heat loss below
the bridge amounts to no more than 15% of the
amount of heat removed at the top of the bridge. In
computing the runoff water heat flux, it was
determined that the water that hits the top surface of
the bridge does not reach the wet-bulb temperature of
the air, as was assumed in the past.
About 95% of the water pumped onto the bridge runs
off the bridge, with only 5% evaporating. From the
energy budgets, it was estimated that after 24 hours,
this concrete bridge released about 210 kJ/kg-solid,
which is good agreement with the calorimetry
estimates.