The fragile nature of the glass requires that mechanical strength tests be carried out on it. Let's see what are the tests that a static glass sample is subjected to.
Trial of the Ax
To determine the specific resistance class of a certain glass composition (stratification) according to the code provided by the reference standard (EN 356), the ax test is carried out. It involves the use of an electromechanical instrumented bench for the realization of repeated blows with percussion tools (hammer, ax). It is a burglary proof or anti-crime proof.
Double wheel impact test
The impact test, or Pendulum test, is performed by a pendulum fall from different heights of a mass of 50 kg consisting of a double weighted wheel. In this way we intend to simulate the impact effect due to an accidental impact on a glazed element. The purpose is to classify a glazed element with respect to the coding provided for by the regulatory text (EN 12600): in particular, the test defines whether a laminated glass can be considered "safety glass".
Drop test with steel balls
The drop test with steel balls consists in performing repeated falls of hardened steel balls from pre-determined heights. This test is used to simulate an act of vandalism aimed at drilling the glazed system
The result of the test is the determination of a resistance class according to the code provided by the reference standard (EN 356).
Measurement of surface compression
The surface compression measurement is a test based on the physical principle of birefringence (photoelasticity). This non-destructive test, carried out with optical and digital instruments, is used to determine and study the permanent tensions present in the glass.
Bending test
The flexural strength test consists in subjecting the glass sample to bending on 4 points or with double concentric rings in accordance with the EN 1288-3 and EN 1288 -5 standards.
Fragmentation test
Tempered glass can be classified as safety glass only if it passes the fragmentation test: this test is performed on heat-treated glass in compliance with the main European standards.
All the tests described above are carried out with great competence by Stazione Sperimentale del Vetro (SSV), active in Murano-Venice since 1956. It is an international research center with an accredited specialized analysis laboratory UNI CEI EN ISO / IEC 17025, which carries out technical-scientific support activities for the entire glass supply chain: producers, processors, glass users, producers of raw materials, refractories and plants for the glass industry, etc. For information: https://www.spevetro.it/
