On Apr 14, 11:19 am, wrote:
On 14 Apr, 14:23, "tonyjeffs" wrote:



I want to make someexposed aggregatefinished concrete blocks to
repair an existing garden wall. They're about 9"x8"x8", tapered
slightly so that they interlock each other a bit like lego.

Is there a book I can buy, or a website that explains a good step by
step procedure?

I've had some success by trial and error, but I'm not getting it quite
right.
I've made formwork out of wood
I'm using a mix 2 sand 2 cement 4 gravel,
Once its in the mould, I screw a lid on, turn the mold on its side,
take off the side and pour extra gravel on the face. Ditto the other
side.
I can get it almost right, but parts will be pitted where the
additional gravel has been too thick.

Here's a pic of an originalhttp://homepage.ntlworld.com/tony.jeffs/block.jpg
(this may stop working as I'm changing isp)

tony

http://wiki.diyfaq.org.uk/index.php?...oncrete_Blocks
explains why that mix isnt recommended. Cant answer your q though.

NT

I think you can improve the quality of your seeded exposed aggregate
in one or both of two ways.
First, make sure the substrate has had time to settle, and allow te
cream to rise to the surface. At this point, the top surface will be
quite moist, and any aggregate that is seeded in should be easily
worked into the top surface. It is possible to seed too early, and
this will result in the aggregate sinking out of sight. It is a good
idea to use some method such a pressing, tapping, or rolling the
seeded aggregate inot the surface, in order to work it inot the
concreate fines, and produce a solid bond to the substrate.
Second, you may find it better to pour you molds to about 2 or 3 cm
from the top, using your regular concrete mix. Then, use a sand/cement
'mortar' mix to complete the fill, and seed the aggregate into that.
Allow the normal mixture to begin to just harden before adding the
mortar topping. This will allow the base to support the topping
mixture, but still provide a good bond between the layers. I have used
this method to create large stepping stones, as well as stair treads
and landings. Normally, I use a roller to press the aggregate into the
base substrate, but on these kinds of surfaces, it was not possible,
so I came up with this method as an alternative.
I have a couple of web pages that show some of these techniques:

http://members.shaw.ca/bomr/ExposedAgg.html
http://members.shaw.ca/bomr/Building_a_patio_bench.html

--- rod.