Chinese glass road studs do not meet requirement of CNS13762

1. Non self-colored

At the moment, all of the “yellow” glass road studs produced by Chinese manufacturers are painted (the glass body is looked colored for the bottom being covered with paint or colorant.) However, what CNS13762 requires is self-colored ones (color of the glass body is produced by adding pigment while the glass is melted.) In other words, none of the Chinese “yellow” glass road studs is qualified for CNS13762.

Per our experience and feedback from our foreign customers, the color and reflectivity of the painted yellow glass road studs fade/decrease with the times due to exposure to the ultraviolet ray in the sunlight. In 6 months, or at most in 12 months, the color fades and becomes hard to recognize. What’s worse, the reflective layer could be damaged, lose its function, and affect traffic safety seriously.

Easy methods to tell if a glass road stud is self-colored or not:
(1) Face to the light, look up at the dome of the glass road stud from a lower angle of 10 degrees or 15 degrees and see if there is transparent section in the dome.
If yes → painted glass road stud
If no (the whole dome is of light-yellow color) → self-colored glass road stud


(2) Look down from the dome top and see if there are the irregular color spots at the grooves that form the logo.
If yes → painted glass road stud
If no  → self-colored glass road stud


(3) See if there are deposits or undissolved pigment at the bottom of the glass road stud.
If yes → painted glass road stud
If no  → self-colored glass road stud


(4) Use a sharp tool (ex. steel nails, scrapers) to scrap off the reflective layer and the painted layer at the bottom of the glass road stud. Place the road stud on a blank sheet of paper and see if the glass body is transparent or not.
If yes (the glass body is transparent) → painted glass road stud
If no  (the glass body is colored)  → self-colored glass road stud


2. Fake impact test result

Most of the Chinese glass road studs are unable to pass the impact test request of CNS13762. To avoid this disadvantage from being revealed, the suppliers would prepare special samples for the test, whose domes are covered with a layer of transparent material as a buffer. However, the said trick could only fool the testing lab and doesn’t improve the performance of the glass road studs on site.
Therefore, before the testing samples are sent for impact test, it is highly recommended to:
(1) Thoroughly clean the dome surface with acetone to prevent cheating.
(2) Take the sample from the lower layers of a pallet, or sample randomly at the construction site.