Locations for thermal monitoring points for a mass concrete pours

[ENGUCR]

Hi guys,
I am encountering a mass concrete pour for a rectangular pile-cap of sized 33 m(L)x8 m(W)x3.2m(D). A temperature monitoring system to be followed for the casting of this mass concrete element using thermocouples at different locations. Can anyone give any suggestions for best locations and spacing of the thermocouples to be used for the pile cap. thanks in advance

 

[SlideRuleEra]

From a heat transfer viewpoint, the middle (vertically) of the pile cap should see the highest temperatures. I would try to locate the thermocouples away from major rebar... probably not much, if any large rebar in the middle (vertically) of the pile cap. Steel rebar is a good conductor of heat and would tend to lower the temperature of "hot" areas by conducting heat to lower temperature regions.

Keep the thermocouples away from the edges, where the temperature will be lower. In general heat will "leave" the pile cap by:

1. Convection to air through the top.
2. Conduction to soil on the bottom.
3. Conduction through concrete forms, then convection to air on the sides.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[ENGUCR]

Thanks SRE. So it will be sufficient to place all together 5 points i.e. at it's volumetric centre, and directly below and above it & directly in sides along the shorter axis of the pile cap. No points required along the longer axis to the sides of the pile cap??

 

[SlideRuleEra]

ENGRUC - I've attached a sketch showing how, IMHO, five thermocouples should be positioned to give an idea of the maximum concrete temperature. Note that no dimensions for precise thermocouple locations are shown... this is intentional. There are too many variables affecting heat transfer to pin down the optimum positions. Just place them near the "middle" in the 8m and 3.2m directions, and evenly distributed, away from the end forms, in the 33m direction.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net