67 replies to this topic Post Order

[cptmayhem]

eccentric1, on 21 February 2012 - 05:24 , said:

Do some tests stabilizing it with cement. Mix enough cement into the dry sand unti it just starts to change colour. Then add enough water so it forms a little firm clod in your hand. If you drop the clod it must still stay fairly intact. You then have less than four hours to place, level and compact the mix. Flash, the point where cement starts hydrating to give strenght takes place within this time. After that it loses strenght and your effort is wasted. The cement may crack in time so leave some expansion joints or construct in alternative panels by putting in formwork. Leave to cure and wet regularly with water for seven days and keep traffic off the surface. I constructed stabilised subbase and base with sand and it carries the loads induced by traffic. Remember sand that is small rough particles (not rounded windblown sand) interlocks and forms a very strong layer when compacted properly at the correct moisture content. Look at the sand through reversed binocular and good light. It works like a microscope and you will be able to see the particle shape.

PM me if you need more info.

Thanks mate... The concrete dry-mix plan would work, but unfortunately this is Tokai we're talking about. For starters, there's no budget to speak of. Secondly - there's no way we can stop traffic on a certain section of trail. It'd be fantastic if we could, but you know the average souff effrican attitude to signs and trail closures...

If it were my back yard, I would have ripped out a bag or 100 of cement mix and gone to town. Unfortunately, we can't. We also have to take into account the environmental impact of the trails. I don't think SANPARKS & TMNP would appreciate bringing cement into the mix (excuse the pun) and "ruining" the natural habitat more than we are at the moment. Yes - it would be fantastic for drainage, and would create a MUCH harder base than the sand/clay mix alone. But it's just not an option for us..

So - for the moment, we're constrained to using the available clay (80 cubes trucked in from housing excavations in Baron's court) and whatever water we can get in with the Jo-Jo containers and the available rain water (which is not really available in summer)

I know very well how the sand / clay mixture sticks together, given enough moisture. The only problem at the moment is that we need mounds of water to be able to "set" the sand / clay mix, and if we don't have enough water to hand its viscosity is all wrong and the trail doesn't "bed down" properly (not to mention sticking to every available tool that we have - spades, Mcleods, shovels & shoes - and the effort is nullified.

I'm afraid that, at the moment, we need to either work whilst it is belting down (only going to happen in winter) or when we have the Jo-Jo tanks available to us... The cement, as good an idea as it is, is just not an option for us...

Meh.

Edited by cptmayhem, 21 February 2012 - 08:51 .

[eccentric1]

cptmayhem, on 21 February 2012 - 08:49 , said:

Thanks mate... The concrete dry-mix plan would work, but unfortunately this is Tokai we're talking about. For starters, there's no budget to speak of. Secondly - there's no way we can stop traffic on a certain section of trail. It'd be fantastic if we could, but you know the average souff effrican attitude to signs and trail closures...

If it were my back yard, I would have ripped out a bag or 100 of cement mix and gone to town. Unfortunately, we can't. We also have to take into account the environmental impact of the trails. I don't think SANPARKS & TMNP would appreciate bringing cement into the mix (excuse the pun) and "ruining" the natural habitat more than we are at the moment. Yes - it would be fantastic for drainage, and would create a MUCH harder base than the sand/clay mix alone. But it's just not an option for us..

So - for the moment, we're constrained to using the available clay (80 cubes trucked in from housing excavations in Baron's court) and whatever water we can get in with the Jo-Jo containers and the available rain water (which is not really available in summer)

I know very well how the sand / clay mixture sticks together, given enough moisture. The only problem at the moment is that we need mounds of water to be able to "set" the sand / clay mix, and if we don't have enough water to hand its viscosity is all wrong and the trail doesn't "bed down" properly (not to mention sticking to every available tool that we have - spades, Mcleods, shovels & shoes - and the effort is nullified.

I'm afraid that, at the moment, we need to either work whilst it is belting down (only going to happen in winter) or when we have the Jo-Jo tanks available to us... The cement, as good an idea as it is, is just not an option for us...

Meh.

I do not even exactly know what a Tokai is. I thought it was for your backyard.

Mechanical modification is the correct option for what you want to do. You will only ttain proper compaction if you have the optimum moisture content in our mix. The mix must be prperly and evenly mixed. A rotovator or kapploeg would be ideal for the mixing of the water and the mix. One of those two wheeled tillers with a kapploeg may just suffice. Go babysteps and remember there are three things that destroys any "road" structure and that is water, Water and WATER. Control that and the formation will last.

[Pain or Shine]

All this free advice.. pardon the interruption, as you were... I am absorbing, pun intended.

[cptmayhem]

eccentric1, on 21 February 2012 - 10:29 , said:

I do not even exactly know what a Tokai is. I thought it was for your backyard.

Mechanical modification is the correct option for what you want to do. You will only ttain proper compaction if you have the optimum moisture content in our mix. The mix must be prperly and evenly mixed. A rotovator or kapploeg would be ideal for the mixing of the water and the mix. One of those two wheeled tillers with a kapploeg may just suffice. Go babysteps and remember there are three things that destroys any "road" structure and that is water, Water and WATER. Control that and the formation will last.

Yeah, absolutely... I've seen enough damage to substrates & surfaces to know that surface prep is key, but the prep of the substrate is even more important... Thanks for the advice though. If I had my own backyard where I could build jumps etc, then this would be the way to go for sure...

Tokai is Tokai Forest, our major venue for MTB trails and part of the Table Mountain National Park. Also a pine plantation, that is being logged and being "put back to nature"

That's the major reason that the concrete wouldn't even make it past the front gate, let alone anywhere near the trails! Also, there's no way of limiting traffic. Public place, souff effrican mentality that says bugger you, I'm gonna ride anyway...

Edited by cptmayhem, 22 February 2012 - 08:25 .

[cptmayhem]

Pain or Shine, on 22 February 2012 - 08:21 , said:

All this free advice.. pardon the interruption, as you were... I am absorbing, pun intended.

How many bags you reckon we'd need to do a proper job of it? 200? 300?

And more to the point - Mr. Bo would, quite literally, sh1t bricks...

Edited by cptmayhem, 22 February 2012 - 08:24 .

[Grebel]

cptmayhem, on 21 February 2012 - 08:39 , said:

You have no idea, bro... on all 3 sides, they have cut back the clay to make a sorta 3-walled box (like they do in Fresnaye and Clifton, high up on the rocks) but get this - there's no retaining on ANY of the 3 walls of clay. There aren't even any weeping holes, or concrete facing on the clay walls. 15m away from the rear wall is a pool of approx 80,000 litres. 10m away from the right hand wall are the neighbour's foundations. My folks are reasonably far away ito foundations etc, so they're not so worried about their place. But it's pulling values of the surrounding houses down by the week. All the run-off goes into the road, and consequently into the property at the bottom that has those geese, and that have just built a new massive outer wall. Yes, there is a storm water drain right on the corner, but it wasn't designed to take the amount of water that will now come through with the altered landscape.

The plastering has only been in place for just over a year, and is already cracking and they're having to repair it. They didn't put any waterproofing in place, and the roof section is TOTALLY level. No angle to it at all. Which means - the water sits. And seeps. They still haven't put a grade onto the roof, and simply patched the cracks in the plaster. They're going to have to re-do the roof in about 3 to 5 years if they don't sort out the waterproofing and ut a grade onto the roof.


And you know how that area can be affected by a summer storm...

They are going to have some serious issues soon.... Can't understand how the local authorities let it go through. The inspector either has a tidy bank balance with a cupboard full of expensive whiskey or he/they are only worried about the lines joining on paper in the plan inspection department. By rights with that extent of excavation and construction, a qualified architect at the very least should have been involved as well as a geowhatever (Soil expert?) to check the moisture/drainage. I just moved a retaining wall back a meter and that has it's own issues... I saw the "damage" to the road a bit further down. Could have been due to excessive run off with the rains we had a few days ago. Glad it isn't my house!

[Pain or Shine]

We have various limitations.. How to get any mix on the trail is a headache for me at the mo. Apart from very manual labour, we have no means of accessing the trail with a sizeable load of material...

This weekend went well though, was able to get two tons of clay straight to the DH trail with a truck on each load.. I wish all our ST had a service road access!

[cptmayhem]

Pain or Shine, on 22 February 2012 - 08:36 , said:

We have various limitations.. How to get any mix on the trail is a headache for me at the mo. Apart from very manual labour, we have no means of accessing the trail with a sizeable load of material...

This weekend went well though, was able to get two tons of clay straight to the DH trail with a truck on each load.. I wish all our ST had a service road access!

Mojo Jo-Jo...

EDIT - if you think about it, we do... Snake Eyes / Rinkhals / DH1 / 2 / 3 all have service roads above and below... A lot of wheelbarrow work will be required, yes... But we can get it there!

Edited by cptmayhem, 22 February 2012 - 08:47 .

[cptmayhem]

Grebel, on 22 February 2012 - 08:29 , said:

They are going to have some serious issues soon.... Can't understand how the local authorities let it go through. The inspector either has a tidy bank balance with a cupboard full of expensive whiskey or he/they are only worried about the lines joining on paper in the plan inspection department. By rights with that extent of excavation and construction, a qualified architect at the very least should have been involved as well as a geowhatever (Soil expert?) to check the moisture/drainage. I just moved a retaining wall back a meter and that has it's own issues... I saw the "damage" to the road a bit further down. Could have been due to excessive run off with the rains we had a few days ago. Glad it isn't my house!

Yeah. Absolutely. He seems to be connected pretty well, though. It's the only way I can imagine the plans were put through as they were, and that there hasn't been much comeback (yet) regarding the construction techniques that he's used and the lack of retaining in place.

But I envision moerse k4k in the not-too-distant future...

[nigelhicks]

bru - id rather work with your sandy **** that this clay! ... fine this clays nice to shape but you cant ride on it when its wet as it becomes an icerink! .... I have used a couple of bags of cement on the track before and it worked well.

Might use some if i need to when we roll the pedal section.

[jimmy hardtail]

It rained all day! Gonna ride tomorrow, track should be perfect. Might have to patch a few tire ruts before they set like concrete...

[cptmayhem]

gonna ride in the morning and check it oooooout!

Jimmy - you know it's Tim's birthday today, right?

[nigelhicks]

some pics taken by Kath Fourie on the weekend

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[nigelhicks]

and some more ...

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[nigelhicks]

the last image here is the NEW 17m step down which leads into the NEW 21m and 20m table tops on the N3 ....

[Super_mil]

Damn, I can't believe those tables got bigger