What is the difference between polished, trowelled and semi-polished concrete?

The difference lies in the work done on the pavement and the finish obtained:

• Trowelling: This is the basic mechanical finish. A trowel is passed over the fresh concrete to leave it smooth, dense and level. The surface is matt and functional, but the pores of the concrete remain open.
• Polished: This is a subsequent treatment on the cured concrete. It involves mechanical sanding with several passes of diamond abrasives and the application of chemical densifiers. The aim is to achieve a very high gloss and completely close the pores of the concrete.
• Semi-polished: This is an intermediate finish. It consists of faster polishing, with fewer diamond passes. The result is a smooth surface with a satin or matt shine, closed pores and easy cleaning.

Trowelling is the mechanical base. Polishing and semi-polishing are subsequent treatments to improve aesthetics and close the pores; the difference between them is the level of shine and the hours of work involved.