By applying a mortar or grout finish coat to new or old concrete flatwork, you can simulate the look of travertine. Often contractors use the technique to enhance pool decks, residential driveways, patios, and balconies.
For new concrete, strike off, bull float, and edge the concrete slab, then broom it with a stiff-bristle broom to improve bond with the finish coat. For an existing concrete surface, check to see if water beads on it. If it does, degrease the surface with a commercial degreaser or cleaner, then scrub and rinse thoroughly. Some proprietary finish coats require application of a bond coat, which you broom onto the wetted concrete surface before applying the finish coat.
You can make your own mortar or buy proprietary grouts (usually made with a liquid polymer and premixed portland cement and fine aggregate). To make the mortar, mix one bag of white portland cement and 2 cubic feet of sand having a uniform moisture content. To simulate the color of travertine, finishers typically add a yellow pigment, but any other mineral-oxide color can be used. When using a proprietary grout, follow the manufacturer's recommendations for mixing the dry materials, liquid polymer, and water. A pigment can be added during mixing, or the finished surface can be stained later.