Perform some NDT (i.e. cores, bond strength, etc.) to determine what you
really have. It could have just been over worked. If that is the case, use
hydro demolition (high-pressure water) to remove the poor quality concrete.
If the depth of material removed is minimal apply the thin set for the tile
directly over it and adjust thickness of bed as necessary. If substancial
material is removed it may be necessary to add an overlay.
(Note: Test maximum specified water pressure on piping and conduits prior to
demolition work to make sure damage or unwanted water infiltration does not
> -----Original Message-----
> From: T. Eric Gillham PE [SMTP:teric(--nospam--at)gk2guam.com]
> Sent: Monday, February 26, 2001 1:47 AM
> To: seaoc list
> Subject: Concrete Problem
> I would appreciate anyone who can give me some help on this one:
> How does one go about hardening and strengthening a layer of concrete that
> has already been cast and cured, without removing the concrete entirely?
> In other words, is there a product that can be added to the surface of the
> concrete to harden it?
> The concrete in this particular case would be difficult to remove because
> of embedded piping. The hardened surface would then have tile set on it,
> and would form the floor of a hot water wading pool. The layer of
> concrete which needs to be hardened was poured over 2 months ago, and is
> quite sandy in color with hardly any hint of gray. This would seem to me
> to indicate a low cement content.
> Anybody have any ideas on this one?
> T. Eric R. Gillham PE
> PO Box 3207 Agana Guam 96932
> Ph: (671) 477-9224
> Fax: (671) 477-3456
> Cel (671) 687-7115
> teric(--nospam--at)gk2guam.com <mailto:eteric(--nospam--at)gk2guam.com>