T

Answers

Which Chinese standard governs terrazzo, and what does it require?

Two standards cover it. JC/T 507-2022 governs the product: its classification, its raw materials, and its test methods. It is a recommended industry standard, not a mandatory one. GB 50209-2010 governs the installation and is a mandatory national standard. Between them they set the topping thickness, the chip size, the flatness tolerance and the wear figure.
Chip size against topping thicknessA horizontal scale in millimetres. For each topping thickness from 8 to 18 millimetres, a bar shows the topping and a second bar shows the largest stone chip permitted, which is two thirds of the thickness. Derived from JC/T 507-2022 clause 5.3.0481216208 mm5.3 mmthe band we supply10 mm6.7 mm12 mm8 mm15 mm10 mm18 mm12 mmTopping thickness (solid) against the largest chip permitted (accent), on one millimetre scale.Chip ceiling is two thirds of the thickness (JC/T 507-2022 cl.5.3).Topping range from GB 50209-2010 cl.5.4.1; the arithmetic is ours.
Chip size against topping thickness, on one millimetre scale. The chip ceiling is two thirds of the thickness, from JC/T 507-2022 clause 5.3; the arithmetic on the thicknesses is ours.

The figures, and where each one comes from

What is set Requirement Source
Topping thickness 12-18 mm, and it follows the chip size GB 50209-2010 cl.5.4.1
Cement to chip, by volume 1:1.5 to 1:2.5 GB 50209-2010 cl.5.4.9
Chip size 6-16 mm, crushed dolomite or marble GB 50209-2010 cl.5.4.8
Largest chip against thickness not more than two thirds of the topping JC/T 507-2022 cl.5.3
Grinding passes at least 3 on a standard floor GB 50209-2010 cl.5.4.5
Flatness tolerance 3 mm standard, 2 mm high-performance GB 50209-2010 table 5.1.7
Wear index not less than 1.5 JC/T 507-2022 cl.6.5.1
Chip mud content not more than 1% JC/T 507-2022 cl.5.4.2
Rock flour particle size under 80 micrometres JC/T 507-2022 cl.5.4.3

Why the processes are not interchangeable

The chip-to-thickness rule is the one worth knowing. If the topping is 12 mm, the largest chip you may use is 8 mm. If the topping is 18 mm, it is 12 mm. This is not a preference, it is how the aggregate stays inside the wearing surface instead of telegraphing through it, and it is why asking a supplier for the chip size tells you whether they have read the code. NTMA publishes the equivalent by chip NUMBER for each system, but no English standard states the relationship between chip size and topping thickness as an arithmetic constraint.

What these figures are, and what they are not

Every figure here is a published requirement quoted from the named clause. None of them is a measurement of anything we have made. JC/T 507 is a recommended industry standard: it says JC/T, which is the Chinese designation for a recommended standard, not GB, which is mandatory. We hold no certificate against either standard, and we have not tested any panel we have supplied.

Measured data sheets and test reports

If you are specifying this

We have not published products against this question yet. Send us the process, thickness and quantity and we will quote it against what we can actually form, rather than against a catalogue.

Send a specification Ask for a sample