How to improve the slip resistance of tile adhesive
Performance characteristics:
When mortar exhibits poor thickness consistency, sagging during application, difficulty in scraping off, or tile slippage during installation, these are all indications of poor slip resistance/sag resistance of the tile adhesive.
Testing methods:
(1)Ensure that the edge of the steel straightedge is placed at the top of the concrete panel. When the concrete panel is upright, the bottom edge of the steel straightedge should be at the same level as the top of the concrete panel. Apply a 25mm-wide masking tape along the bottom edge of the steel straightedge. Apply a thin layer of adhesive using a straight-edged trowel on the concrete panel.
(2) Apply another thick layer of adhesive on the concrete panel surface to completely cover the bottom of the masking tape.Use a 6 mm × 6 mm (center distance 12 mm) notched trowel to comb the adhesive.
(3) Hold the notched trowel at an angle of approximately 60° to the concrete slab and apply the adhesive parallel to the edge of the slab.
(4) Immediately remove the masking tape and place a 25 mm wide spacer (or strip) tightly against the bottom edge of the steel straightedge.After 2 minutes, place the ceramic tiles tightly against the spacers (ceramic tile requirements: water absorption rate determined by boiling method is 0.1%–0.5%, unglazed, surface dimensions are 100±1mm × 100±1mm, weight is 200±10g,and thickness of 8 mm to 10 mm), and place a weight of 5.00 ± 0.015 kg on the ceramic tile. Maintain this for 30 ± 5 seconds.
(5) Remove the spacers and measure the distance between the edge of the steel ruler and the ceramic tile using a Vernier caliper, accurate to ±0.1 mm.Immediately after measurement, carefully stand the concrete board vertically. Re-measure the distance between the straight edge and the ceramic tile after 20±2 minutes. The difference between the two measurements is the maximum sag distance of the ceramic tile under its own weight.
(6) Test each adhesive with three ceramic tiles. The results in the test report are the average values of the tests.
Solution:
1. When mortar exhibits sagging, we typically use starch ether, which enhances the mortar’s viscosity, structural integrity, sag resistance, and workability. Thixotropic lubricants may also be used to control the mortar’s viscosity, yield point, stability, and workability.Starch ether and thixotropic lubricants are commonly used. However, considering overall costs, excessive starch ether may negatively impact the strength of tile adhesive. Therefore, we recommend using both in combination.
2. When the addition of starch ether or thixotropic lubricants has reached its limit and further improvements in sag resistance are minimal, we recommend using functional cellulose ethers, such as Tianpu 30011C. This material can maintain the water retention of tile adhesive while partially substituting the functions of starch ether or thixotropic lubricants, thereby reducing overall costs.
