ᐅ Efflorescence on Concrete Pavers When Using Recycled Concrete Aggregate
Created on: 19 Jan 2020 12:39
G
Golfi90
Hello everyone.
We are currently wondering whether using crushed stone with a rating of RC is sufficient, or if it really has to be the mineral mix that costs more than twice as much.
We will be installing anthracite concrete pavers.
The surfaces will be fully exposed to the weather, meaning they will get wet from rain.
What are your experiences with this?
We are currently wondering whether using crushed stone with a rating of RC is sufficient, or if it really has to be the mineral mix that costs more than twice as much.
We will be installing anthracite concrete pavers.
The surfaces will be fully exposed to the weather, meaning they will get wet from rain.
What are your experiences with this?
So it seems my concerns were unfounded! Very good!
We will also use concrete pavers on the terrace, but as a precaution, we will design the last 10 cm (4 inches) of the base layer with mineral crushed stone. You never know if terrace slabs or natural stone might be used there later. At least this way the substrate is perfectly prepared in advance.
We will also use concrete pavers on the terrace, but as a precaution, we will design the last 10 cm (4 inches) of the base layer with mineral crushed stone. You never know if terrace slabs or natural stone might be used there later. At least this way the substrate is perfectly prepared in advance.
Zaba12 schrieb:
I have mainly heard that anthracite-colored paving stones tend to effloresce, but why should that be related to the base layer? I would rather assume it comes from the paving itself. fragg schrieb:
How is anything supposed to move upward against gravity and against the flow of water through the gravel? Due to the capillary effect of the paving or brick stones, dissolved salts from concrete residues in the base layer are drawn to the surface of the paving. There, the pure water evaporates, causing efflorescence as the formerly dissolved crystalline salts crystallize on the surface. Under carports or similar structures, the lack of surface runoff worsens this effect.
That’s the theory.
In practice, thin layers of gravel with grain sizes larger than 4 cm (1.6 inches), acting as a capillary break, effectively separate and drain the layers.
For more detailed information, see for example:
Methods to avoid the “carport effect” (by an expert, available as a PDF on Metten’s website)
In masonry, a horizontal damp-proof course is commonly installed to prevent moisture rising through the capillary effect.
Vicky Pedia20 Jan 2020 16:14Otus11 schrieb:
Due to the capillary action of the paving or klinker bricks, salts dissolved in water from concrete residues in the base layer are transported to the surface of the paving, where the clean water evaporates and can cause efflorescence from previously dissolved crystalline salts. This effect occurs occasionally. However, the minerals often originate from the stone itself. A capillary break layer is still necessary, of course. These efflorescences can be easily removed with a high-pressure cleaner if needed. After one or two cleanings, the issue usually disappears permanently.