Overview
EN ISO 10545-4:2019 - "Ceramic tiles - Part 4: Determination of modulus of rupture and breaking strength (ISO 10545-4:2019)" is the CEN-adopted international test method for measuring the mechanical flexural performance of ceramic tiles. The standard specifies how to determine the breaking load, breaking strength, and modulus of rupture for all ceramic tiles using a central-load bending test and defines sample selection, test apparatus, procedure and calculation rules.
Key topics and technical requirements
- Scope: Applies to all ceramic tiles; provides a laboratory method to quantify flexural resistance.
- Test principle: Apply a force at a specified rate to the tile centre (glazed or proper surface uppermost) until fracture; record breaking load and compute breaking strength and modulus of rupture.
- Definitions & calculations:
- Breaking load (F): force at fracture (read from pressure gauge).
- Breaking strength (S): breaking load × (span between support rods / specimen width).
- Modulus of rupture (R): breaking strength divided by the square of the tile’s minimum thickness along the broken edge.
- Apparatus:
- Drying oven (105 ± 5 °C) or equivalent drying system.
- Recording pressure gauge (accuracy 2.0%).
- Two support rods and one central loading rod covered with rubber (hardness 50 ± 5 IRHD per ISO 48-2); rod diameters, rubber thickness and overlap depend on tile size (see Table 1 in the standard).
- Specimens & sampling:
- Requirements differ by work size thickness (≥ 7.5 mm vs