Folks:
Has anyone heard of adding lead to concrete mixes, to increase
weight/density? I just was told that the Jamesburg Earth Station, with huge
amount of concrete and rebar required for the self supporting 30 meter
diameter dish building and foundation, had some sort of lead shot entrained
in the concrete, in order to increase weight, and, ostensibly to reduce the
foundation volume required to support the (free standing) big dish. Rumor
had it, some of the concrete trucks [see below] broke drive train and
suspension components, due to their loads' extra heavy weight due to the
lead that was put in the concrete. I am trying to validate the story. In
the photos below, the concrete portion of the antenna support pedestal,
extends to the point where the attachment bolts can be seen at the perimeter
of the base of the steel turret. The concrete continues to a deep and
heavily reinforced foundation.
Is it possible that, like any free standing tower, WEIGHT is the driving
factor in foundation deisgn, and in order to reduce cubic yards of
excavation, and concrete, that lead was added to get enough weight into this
foundation?
Jamesburg Earth Station Pictures:
Picture taken 2006
http://www.longandflatsociety.com/Galleries/JamesburgEarthStation/tabid/466/Default.aspx
Pictures from Late 60s, during construction:
Concrete Trucks, Foundation Pour
http://www.comsat-history.com/albums/Jamesburg/Jamesburg_Dec_11_1967_Pouring_concrete_for_antenna_footings.sized.jpg
Footing
http://www.comsat-history.com/albums/Jamesburg/Jamesburg_Jan_12_1968_Footing_of_antenna_bldg_forms_for_ant_lower_pedestal_foundation.sized.jpg
Pedestal
http://www.comsat-history.com/albums/Jamesburg/Jamesburg_Jan_23_68_Antenna_mount_with_foundations_for_antenna_bldg_in_foreground.sized.jpg
Pedestal
http://www.comsat-history.com/gallery/Jamesburg/Jamesburg_March_12_1968_Antenna_complex?full=1
Antenna Lift
http://www.comsat-history.com/gallery/Jamesburg/Jamesburg_May_27_68_Lifting_antenna_reflector_into_place
73,
Pat AA6EG aa6eg@hotmail.com
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
