So as to achieve a certain desired exposure level for a particular aggregate mixture finish, your concrete should be able to undergo a few of the onsite processes. This article shall provide with a general outlook on how finishes are achieved and on what goes on the process, at the same time the ways there can be environmentally friendly within the process to ensure that there is an impact within the environment. After placing the concrete, decorative aggregate will be revealed. There is various exposure methods contractors are able to choose from, as per the looks desired from concrete driveways as the rest will remain permanent embedded within the concrete. The rule of the thumb is to be able to remove the surface mortar in depth within one third of the diameter for the aggregate particle.
Brushing and washing
Brushing and washing is basically the oldest and even the simplest method available as they do not require retarders or even special tools. You only need to wash away thin layers of the surface mortar that covers the aggregate through spraying with water and then scrubbing it with a broom then wait until it is exposed to the desired depth. Timing is very critical; therefore the method is quite often suited for various small jobs. The work must start after the surface mortar is able to be removed without the overexposing or even dislodging the aggregate. You could be able to test this through brushing it away lightly the surface mortar within a small area using brooms with stiff nylon
Currently, contractors are able to expose the aggregate though spraying using a chemical surface retarder on the slab surface as soon as possible when placing and finishing has been done. This will delay the set and provides the flexibility of removing cement paste for a day or even more than a day, it’s done through either scrubbing or even by pressure washing. This flexibility is very important on huge construction jobs or when there is a hot weather. There are various surface retarders in the market that always provides specialized services. For example most retarders produce a decorative exposed aggregate finishes. The surface retarders can be easily mixed in water within the field for the application in a low pressure sprayer. The retarder will permit the removal of surface mortar especially within 24 hours when the initial concrete set. In vertical surfaces especially exposed aggregate concrete sideways, you could be able to find chemical retarders which are especially thick to be painted
It can be possible at the same time to expose the aggregate when the concrete has already been set and then burdened using abrasive blasting either through shot blasting or even sandblasting. The only disadvantage with this method is that sometimes it can fracture aggregate and even its dull appearance. This method is never a better option when preserving the shape and even color intensity of aggregate as its essential
The above methods can achieve decorative exposed aggregate concrete finish. For more information visit www.designerpremix.comau