Chert driveway

[durtynacho]

Hi all,

This type of rock is supposed to be like road base, or what some call crusher run. 3/4" minus with fines. But, it is supposed to pack better than typical base. In Texas, they use recycled concrete for base and it damn near turns back into solid concrete after a while, which I loved. Supposedly Chert does the same. But the local quarry told me it is a more jagged rock, which helps it lock but also makes it hard to walk on.

I have no experience with this stone. Anybody able to offer up their opinion on it? Do you like it better or worse than base stone? Do you find it hard to walk on, and does it indeed pack and hold together better than typical base stone?

Thanks in advance.

 

[dusty3030]

Depends on your location. Chert you can get here in west TN doesn't hold very well, it washes but it's cheap so people use it. Put crushed limestone on top of it and it holds fine.

 

[durtynacho]

Depends on your location. Chert you can get here in west TN doesn't hold very well, it washes but it's cheap so people use it. Put crushed limestone on top of it and it holds fine.

Middle TN here, so will probably be the same. Thanks Dusty.

 

[ponytug]

Chert is much harder (MOHS 7) than limestone, but smoother. So, some good, some bad. I would not use it alone, because it requires better (more/heavier) compaction than limestone or recycled concrete, and due to the hard smooth nature of the pieces, it does not hold together by itself. It makes great aggregate for concrete or asphalt. If it were me, I would apply it with a mix of lime, fly ash, or cement, at the five per cent or more level, or use it with a heavy mix of crushed limestone, wet it, and compact it really well.

This article uses it mixed with a few other things, like concrete and asphalt millings;

https://onlinepubs.trb.org/Onlinepubs/HRBbulletin/108/108-017.pdf

It is old (Fifties?), but the chemistry of soil and the challenges haven't changed much...

The Romans used it under roads as a base for other rocks and gravel probably because of the strength of chert.

All the best,

Peter

 

[bdhsfz6]

I guess different areas have different names for the stuff. Around here, they call it 2RC Modified. Put down wet and rolled, it holds very well. It can be tough to walk on with bare feet though.

During dry spells, it can get dusty but a little calcium solves the problem.

 

[Streetcar]

I guess different areas have different names for the stuff. Around here, they call it 2RC Modified. Put down wet and rolled, it holds very well. It can be tough to walk on with bare feet though.

During dry spells, it can get dusty but a little calcium solves the problem.

Chert is type of sedimentary rock such as shale, limestone or sandstone