Quality in concrete spacers

Concrete spacers of Molenaar Betonindustrie are produced conform the Dutch "KOMO Productcertificate K23195/03" regarding "Cement-bonded spacers" to the Dutch BRL 2817.
The KOMO certificate also refers to the environmental class of the concrete spacers. The environmental class is explained in the Mix design standards of the EN 206-1 and the Dutch NEN 8005
The KOMO certificate guarantees the continuing quality  of the Concreter spacers and bar supports of Molenaar Betonindustrie.
All the concrete formworkspacers are produced under the Dutch "NL BSB productcertificate K20539/02" regarding "precast concrete elements" to the Dutch BRL 5070
The products of Molenaar Betonindustrie are supplied in various types of concrete on request. In the link below you can find the properties of our standard concrete types including water penetration and the compressive strength. 
The concrete spacers and bar supports of Molenaar Betonindustrie are used to prevent principal concrete corrosion and deterioration.
This is all explaned in the link below.
Providing a correct cover of the rebar can be done with concrete and plastic spacers. The qualaty of the concrete structure also depends on the products used for cover spacers. The link below explanes some of these quality differences.