Wow for exterior rated fill material I would recommend some bonstone products such as ultimate and or glacier. These products are urethane based and should work well.
However that floor looks like an invitation to disaster. Sorry but (and Fred May agree) there is a reason that material is failing. Lack of grout, insufficient grout joint,moisture ,installation issues etc may be some things to consider. Am not sure if this is the right quote but things that are in motion tend to stay in motion.

Sent from my iPhone

> On Feb 19, 2019, at 4:14 PM, Ken Pistoresi <ken@cleansweepbakersfield.com> wrote:
>
> Partners this is travertine installed on outside patio.  Client wants it
> cleaned cracks, and spalled areas repaired . Does anyone have a
> recommendation on repair material? The stone will be exposed to the sun and
> it is over 100 degrees in the summer here.  Depending on the cleaning
> outcome I may do a light cut to give it a cleaner look. Any thoughts? Client
> is aware this is not a permanent fix and is willing to do periodic
> maintenance.  Looking forward to your thoughts.
> Ken
>
> -----Original Message-----
> From: Ken Pistoresi <ken.pistoresi@icloud.com>
> Sent: Monday, February 18, 2019 4:25 PM
> To: Ken Pistoresi <ken@cleansweepbakersfield.com>
> Subject: Tr
>
>
>
>
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