Classes of Polished Concrete & Terrazzo - Polished Concrete Council of Australia

Class A

Minimal Exposure

Cream Polish/ Burnished Concrete

minimal exposure of the fine aggregates. This requires concrete placement at or above FF -70. The high FF requirement of the initial concrete placement is critical to maintain a uniform appearance while minimizing exposure of aggregates.

This floor will have 85%-95% cement fines with 5%-15% fine aggregate.
The surface should be heavily troweled to obtain as smooth, dense and hard a surface as possible. “Burnished to black”
The cause of the exposure is down to the floor flatness and effective troweling of all areas of the floor.

Partial Exposure

Hit n Miss, Partial Aggregate Exposure

This finish provide a more industrial look and can be called hit n miss, partial aggregate exposure and several more names.
Concrete placement at or above FF -45 is needed to maintain a uniform appearance while minimizing the exposure of larger aggregates.
The more the concrete surface is worked the further down the aggregate will be pushed. It is important that the floor is level as this will affect the amount of stone that is exposed.
A very poorly leveled floor will require significant grinding which will ultimately expose a high level of aggregate.

Full aggregate Exposure

Class C – Medium aggregate: exposure of mid-ran ge aggregates. All surface paste is removed with grinding. Concrete placement at or above FF -35 is recommended.
Class D – Large aggregate: expo sure of the course aggregates similar in appearance to terrazzo. All surface paste is removed with grinding. Concrete placement at or above FF -25 is recommended.
Ideally the class C/D finish has 80%-90% large aggregate with 10%-20% cement fines and fine aggregate.
All boot holes must be filled with fresh concrete and not just filled in with slurry as this will leave footprints in the surface which cannot be ground out.
The screed should also never rest or be excessively pushed into the surface as this will also cause the aggregate to be pushed down and this cannot be fixed later

Grind and Seal

Class S-A: Cream; minimal exposure of the fine aggregates. a light sand often with transitionals is conducted and the floor sealed with a topical
sealer.
Class S-B- Salt and Pepper: exposure of all the small aggregates. This yields a worn , industrial look. The floor is ground with finer diamonds after exposure and then sealed with a topical sealer.
Class S -C – Medium aggregate: exposure of mid-range aggregates. The floor is ground with finer diamonds after initial grinding to expose the aggregate and then sealed with a topical s ealer. These floors are not densified and highly polished but may sometimes require grouting
Class S -D – Large aggregate: exposure of the course aggregates similar in appearance to terrazzo. The floor is ground with finer diamonds after initial grinding to expose the aggregate and then sealed with a topical sealer. These floors are not densified and highly polished but may sometimes require grouting.

Classes of Terrazzo systems

Rustic Terrazzo- Terrazzo with a non-ground, textured surface, for exterior use. This system is available with Bonded and Monolithic Terrazzo
Bonded Terrazzo: A cement matrix and underbed system for interior and exterior areas where conditions require 30mm to 45mm of recessed depth to be filled in addition to the 13mm terrazzo topping.
Monolithic Terrazzo- This 13mm thick cement matrix veneer placed upon a provided concrete slab is dependent on the concrete quality for flatness and crack prevention. On grade or below grade only.
Polyacrylate Terrazzo- A nominal 10mm think polymer modified cement matrix veneer placed upon a provided level concrete slab. Polymer provides strength to allow for thinner applications of cementitious systems.
Epoxy Terrazzo- A nominal 6mm or 10mm thick resin matrix veneer placed upon a level concrete slab; Also can be specified with glass, synthetic, or granite aggregates in lieu of marble to provide brilliant colors or chemical resistance.
Sand Cushion Terrazzo: A cement matrix topping underbed with wire reinforcing, isolation sheet, and sand layer system for interior floor use.

Classes of Gloss Level

Polished Concrete Council of Australia Polished Concrete Appearance Chart
LEVEL	NAME	Distinctness of image (DOI) gloss	IMAGE CLARITY VALUE %
1	Honed	Images of objects being reflected have a flat appearance with zero reflection. This is a high non-slip option used in exterior areas	0-9
2	Flat/matte	Images of objects being reflected have a matte appearance	10-39
3	Satin	Images of objects being reflected do not have a sharp and crisp appearance but can be identified	40-69
4	Highly Polished	Images of objects being reflected have a sharp and crisp appearance as would be seen in a mirror like reflection	70-100