This is the most important decision when beginning a diamond grinding project and often it relies on learning from mistakes. With experience you may often be able to make an informed guess as to which compact disk is going to be right for any different slab.
There are some simple statements that can be a fact before we go on:
— even the best or biggest machine won’t look good if the incorrect tooling is installed.
— there is really no such thing as a flawed diamond compact disk. It is always whether the compact disk is right for that particular concrete. There will be a ‘right’ slab for every compact disk.
— no two slabs are the same, even for a passing fancy project. Indeed, a slab can vary from section to another for a passing fancy slab poured for a passing fancy day.
— there is no such thing as ‘one diamond compact disk is right for different types of concrete floor’.
— the ‘mpa’ of a slab may have little regarding how hard it is to slow. (See para. 1 below).
— premium cds will operate satisfactorily over a bigger choice of different concrete solidity:
Budget cds, as a rule will work best over a narrower band of hardness’s. Premium cds have higher levels of diamond resolution in the individual too, and have different ratios of natural to man made diamond resolution.
1. What do we mean by ‘hard concrete’?
When discussing how hard concrete is to slow, many people confuse SOLIDITY and STRENGTH. Strength is measured in MPa and is a measure of compressive strength. It is true that high compressive strength can be harder, but not always. This because the aggregate and sand vijayalakshmi wet grinder in high MPa concrete may very well be the same in low MPa concrete. The difference is in the amount of concrete floor and water (slump). This also why 40MPa concrete from the batching plant is not 40 MPa when placed, if the contractor adds water; it could just as easily be 15MPa. (Note: you can’t actually ‘pour’ 40MPa concrete, it is too stiff)
When we talk about solidity (to grind) it really is all about the kind of dust that is produced during the process. Hard concrete will produce ultra fine, talcum powdered fine dust. This dust is very un-abrasive; it does not wear the matrix of the diamond message completely. The result is that the diamond resolution soon becomes hardly exposed so it grinds even greater, powdery dust; the message ends to slow, and the portions may even get hot and glaze over. Simple isn’t it? (‘Exposed’ means; how much diamond resolution is poking out of the message. You can tell how exposed the resolution is by massaging your finger over the segment))
This is why why highly burnished (over-toweled) slabs are difficult to slow fast; the dust is so fine the dust is not aggressive enough. The same principle can happen when you slow a normal solidity slab and the top grinds quite normally, but when you begin getting into aggregate, the dust created from the aggregate may be fine and does not wear the matrix completely; so, it begins to slow slowly. Of course, the other can happen; the dust from the aggregate may be rough and slow too well, open up the diamond message too much and cause fast wear. In addition, the type of sand used will change the abrasiveness as well as the aggregate. It comes home to experience and regular checking of your diamond tooling
Concrete that is soft or water damaged (through addition of extra water to the mix before discharging from the truck or rain damaged) produces very soft, gritty, remote, dust; this is too aggressive for most cds and will put them on out very fast. THIS IS NOT A FAULT WITH THE COMPACT DISK. It is merely a case of using the wrong tooling and/or not examining regularly.
So now we know that the AGGREGATE, and the SAND, and also the amount of WATER added to the mix, plus also the amount that it was power TROWELED, plus also whether the contractor VIBRATED the wet concrete all contribute to the final picture as to how easily the slab is going to slow.
2. WHAT COMPACT DISK FOR HARD CONCRETE?
Grinding hard concrete means that the dust is soft and un-abrasive (see Para. 1 above) so the metal MATRIX that the message consists of needs to be ‘soft bond’ and easily eroded to expose the diamonds. Normally a coarser resolution can be beneficial because it may produce coarser dust to help erode the matrix.