Browse Forums Paving & Concreting Re: Best method of curing an exposed aggregate driveway? 21Mar 19, 2011 9:14 pm Concreting like a fair few other trades is one of those trades where a few blokes can do a few weeks work and think they can make a living out of it- unfortunately if they don't have adequate training, experience the client can suffer. Especially with concrete, where you really only get 1 chance at a good job otherwise it means a lot of work pulling it all up again. Some guys do their exposing different ways, some hose off the next day, on our jobs we do it a few hours after the pour with a garden hose and decent nozzle, we do it this way as it is easier to get a more consistent result than coming back the next day to high pressure wash it. But it depends on what works for whom. The quality of mix has a lot to do with it too- we don't really use the big companies for exposed mixes, only normal or colour mixes. The companies known for exposed supply know how to mix it right in the right quantities so it comes out mickey mouse. We usually use 25Mpa which is good the majority of the time, 32 would be extra insurance but it is harder to work (especially if your the unlucky bloke on the screed!) Planned Landscape Constructions http://www.plannedlandscape.com.au Find us on facebook http://www.facebook.com/profile.php?id= ... 9907611509 Re: Best method of curing an exposed aggregate driveway? 22Mar 20, 2011 12:28 pm Aiah 32mpa is more expensive, but for the size of the area your doing its not going to be that much. I think you should use it just to set your mind at ease. Thanks Aiah. I will request 32mpa, then if they add water I will at least be confident the strength is not overly compromised. onc_artisan ...and yes probably not the person for the job Pray for a decent finish for me then- I think I need it! Lex Another really bad thing for the owner - the more you know about the steps or materials, etc., it simply doesn't help in the end. Just gets you more frustrated when you see how and what they do. We're talking about things that are so simple and common sense, not worth discussing, as they are a given in specific trades. Still, opposite happens. Ignorance is bliss, ain't that the truth! Planned LScape Concreting like a fair few other trades is one of those trades where a few blokes can do a few weeks work and think they can make a living out of it- unfortunately if they don't have adequate training, experience the client can suffer. Especially with concrete, where you really only get 1 chance at a good job otherwise it means a lot of work pulling it all up again. Some guys do their exposing different ways, some hose off the next day, on our jobs we do it a few hours after the pour with a garden hose and decent nozzle, we do it this way as it is easier to get a more consistent result than coming back the next day to high pressure wash it. But it depends on what works for whom. The quality of mix has a lot to do with it too- we don't really use the big companies for exposed mixes, only normal or colour mixes. The companies known for exposed supply know how to mix it right in the right quantities so it comes out mickey mouse. We usually use 25Mpa which is good the majority of the time, 32 would be extra insurance but it is harder to work (especially if your the unlucky bloke on the screed!) Thanks mate- I will post photos of the finished product (hopefully not in the problems with concrete thread)! Re: Best method of curing an exposed aggregate driveway? 23Mar 21, 2011 10:38 am As some of you understand it already, not claiming to be any sort of expert in this area or giving actual advice, just having a great interest in all things concrete and posting an ocassional personal opinion or extracts from literature which caught my eye (for which, of course, I cannot guarantee its correctness or even say that I agree with all of them) ... So, just found this bit and thought it was interesting and funny (or rather - sad), so I thought I should post it in here (this being one of the newer concreting threads). Here we go: "On occasions concreters claim to be so experienced and expert that they do not require bar chair supports for the reinforcement. We have had cause to test this theory more than once to find (to nobody’s surprise but the concreters) the fabric resting neatly on the dirt below the slab where it is useless. Supporting reinforcement on bar chairs at minimum of 1000mm centres (we prefer 800mm) is mandated by the code)." ... actually, Kind of along the lines of some posts in this thread ... My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 24Mar 21, 2011 11:56 am BTW.. 7mm stone? that is way too small it needs to be 14mm or they will fall out. 7mm stone is crusher waste, not what you want! Better find someone that knows what they are doing IMHO Where you are coming from is where you are going to... Re: Best method of curing an exposed aggregate driveway? 25Mar 22, 2011 7:31 pm onc_artisan BTW.. 7mm stone? that is way too small it needs to be 14mm or they will fall out. 7mm stone is crusher waste, not what you want! Better find someone that knows what they are doing IMHO Oh no, tell me this is not true! I actually asked the concreter about the size of the stones and he told me that 7mm will provide the most consistent result because if you go bigger (10 or 14mm) then the mix will also contain some of the smaller stones and seeing as you can't get smaller than 7mm, this will provide a uniform mix. I think I remember him saying that 7mm was more expensive than 14mm?? I don't think I can change this as this is my builder's standard specifications. I actually have a photo of a sample in my first thread (see 'Salt and Pepper' in the first post- viewtopic.php?f=22&t=40301). I personally don't have a preference either way in respect of the size of the stones- I imagine the smaller the individual stone, the less sharp the edge?? If you guys with your professional experience think that 14mm is better or more aesthetically pleasing then please let me know and I will see if I can get this changed. Also, if I increase the bluestone from 7 to 14mm, should I do the same for the 10% pebble?? In other news, I told my concreter I wanted 32mpa strength concrete (they usually provide 25mpa as standard). He said that he is happy to provide 32mpa but wanted me know that there is a greater risk of cracking???!!! This sounded ridiculous to me. His reasoning was that by adding more concrete to increase the strength you would have more concrete overall, thereby the more concrete the likelier it is to crack. He seemed to get all muddled at this point and told me to seek the advice of a "concrete expert". So... what do you guys make of this??? Cheers Re: Best method of curing an exposed aggregate driveway? 26Mar 22, 2011 8:11 pm IMHO only it stands to reason that a 7 mm stone will only stay stuck if more than 50 % remains embedded in the concrete mix. 14 mm allows more than 4mm to be revealed and no risk of falling out. 32 mpa more likely to crack I don't think so... it is all about the curing method... or if cured at all, the grano controls things except the weather. Where you are coming from is where you are going to... Re: Best method of curing an exposed aggregate driveway? 27Mar 25, 2011 8:49 pm Hmmm... thanks onc, you raise an interesting point. I don’t feel comfortable asking to change the mix now seeing as it’s quite late in the game and I have already been very pushy and demanding with the specs. The good thing is that if I’m not happy with the finished result then it will be my builder’s problem to rectify as it’s part of my contract. Also, there are a few homes around my estate that have the Salt & Pepper mix as it’s somewhat popular and I haven’t noticed stones falling out- even on the driveways that were poured a while ago. Will see how we go anyway. In other news my driveway has been boxed out so not much longer to the big day! I am happy with the work he’s done so far. I am attaching some pictures below for you to cast your professional eye over. The mesh looks a lot thinner than I thought it would though- does anyone know how I can tell if it’s F72??? Cheers guys Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Best method of curing an exposed aggregate driveway? 28Mar 25, 2011 9:18 pm F72 = 7mm rod at 200 mm spacings. But Ummm where is theWPM (plastic) Where you are coming from is where you are going to... Re: Best method of curing an exposed aggregate driveway? 29Mar 26, 2011 9:15 am Is that roadbase or some other "base"? I wonder why do they use this coarser base and not sand? Your place looks good, inverell BTW, were you there when they were placing this? Have they compacted the roadbase (or whatever mix that is)? And why is it that some driveways are dowelled into other slabs/concrete, while some are separated from them by a spongey expansion joint? I'm pretty sure that our Council requires the use of a "sponge" isolation joint at the property boundary and the street gutter ... My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 30Mar 26, 2011 9:36 am I have more questions Just noticed that you said "FYI he will also be providing Dowell bars to the garage slab and crossover as well as an expansion join to the garage slab." So, does he still actually need to dowell into the garage slab? And how does that work, since he'll also be using the expansion joint at the same location? Also, about the saw cuts. I thought that the initial placement of the mesh should be pre-planned in relation to where the saw cuts will be?! This is because I thought that the cover to the mesh should always be maintained - including at the saw cuts. If he doesn't plan for this (by, I guess, separating the mesh, or whatever else needs to be done), then the cut might go all the way to the mesh, which then leaves all the area along the saw cut vulnerable to rusting? Can somebody please explain this? And yes, thanks to inverell, I think that this thread will surely be a useful resource for other members too (one down ) My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 31Mar 26, 2011 4:01 pm onc_artisan F72 = 7mm rod at 200 mm spacings. But Ummm where is theWPM (plastic) I havnt seen plastic used under a driveway for years. They may be going to cut the steel out where the saw cuts go... most likley going to saw through it. yes it exposes the steel to corrosion, could become a problem in 20 years or so. still its always best to cut the steel prior to placement. expansion can be placed around the dowels, its seems obvious to me though to punch the dowels through the expansion material would be easier, rather than cutting it. Re: Best method of curing an exposed aggregate driveway? 32Mar 26, 2011 8:29 pm Hi guys. Well imagine my surprise when I rocked up at my house this afternoon and saw my driveway poured and covered in hessian!! The concreter told me he wouldn’t be doing my job until Monday so I had quite a shock. Needless to say I love the colour- it has turned out much darker than I expected and is almost a perfect colour match to my roof. The weather was perfect today here too- 18˚C and up to 80% humidity. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Thanks onc_artisan for the explanation of mesh specs. I can’t check now obviously but does it look like it’s F72?? I was going to ask you if it would be worth buying my own plastic but it looks like that won’t be happening now. According to bashworth’s link to residential concrete guidelines on the first page of this thread, plastic lining or a 20mm thick layer of sand is recommended if you have reactive soil to minimise friction between the concrete and subbase. I don’t think my soil is particularly reactive so hopefully all will be ok. I hope this is not a critical omission??? Like Aiah has said, I also have never seen it used. Lex- yes, that is some sort of crushed rock subbase and I saw him compact it so all good. The expansion joint foam and Dowel bars will separate the garage slab from the driveway- he just hadn’t fitted the foam at the time of the picture. Now that the mesh is tied to the Dowel bars he had to cut it instead to fit over. I am not having the foam to the crossover- whether it is a council requirement or not I wanted the driveway butted up against the footpath anyway to prevent rain water getting inside the joint seeing as my driveway is on a slope. I don’t think the mesh will be a problem for the saw cut locations as it is about 50mm from the top and the cuts are about 35mm deep- or so I am told. The only consideration for the mesh should be that it is not doubled over at the saw cut locations. I personally wanted to preplan the saw cut locations and to have the mesh cut accordingly but my builder and concreter both told me that I am way over thinking and complicating this! I have marked potential saw cut lines on the photo below- what do you guys think if I get him to cut the driveway like this?? Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ His crew will be exposing the aggregate tomorrow with a high pressure wash and after a few days will be cutting and sealing it. I will be watering the hessian in the morning and evening after the aggregate has been exposed to help it cure- is this too much or am I doing a good thing?? Oh and thanks for the compliments on my house Lex- I stand on the street for hours staring at it like the guy from the Colorbond commercial. My neighbours must think I’m nuts (though I have caught them staring on occasions too haha). Re: Best method of curing an exposed aggregate driveway? 33Mar 27, 2011 7:02 am It looks great!! Just keep the hessian wet all the time. I'm surprised (after all that's been initially planned, like no chairs ) that he went and put hessian! Maybe your talk finally got to him, good to know ! With regards to saw cuts, I found this doco on concrete.net (my fav read ) ... .... ... ... trying to find you the link, but their site is down right now ... anyway, it's on http://www.concrete.net.au and I think under Residential, then just search for 'driveways'. It has all the theory on cuts, with a diagram too According to this site (and also plain logic), the granular sub-base should help reduce restriction of concrete movement. I am not sure why many seem to use a more coarse base (like yours) rather than sand?? Is this decision purely based on cost? If the client wants a good job (and is not scared to pay for it), why do they still keep the components to the bare minimum (and under)?? You say "I am not having the foam to the crossover - whether it is a council requirement or not, I wanted the driveway butted up against the footpath anyway to prevent rain water getting inside the joint seeing as my driveway is on a slope." - can you please tell me the reasons? I didn't think there would be any issues with water? We'll have almost the same slope at that area and I was looking forward to isolation joint there (Not sure if we are in the same council, but I'm sure ours wants the sponge plus 125 thick concrete at the crossover section.) Also, do you know who is this concretor (company name)? They seem to have turned good in the end, fingers crossed for the final part! My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 34Mar 27, 2011 10:22 am Thanks Lex! Apropos the hessian, I think he might have had the slightest inkling that curing was important to me seeing as I would only bring it up every single time we spoke lol. He probably used the hessian to avert the risk of me laying and wetting my own because he would always labour the point that the hessian should not be wet until after the aggregate has been exposed the next day. His logic was that doing so may dilute the chemical retardant they place on top, though more probably he wanted to avoid me hosing the driveway and potentially staring to expose the aggregate mix myself. Thanks for the link- I will check it out. Ideally I would have liked him to have used a more finer subbase or even sand but honestly I am just happy he properly compacted it as I see many that don’t even do that. You can’t see from the picture but when he compacted the crushed rock he actually pulverised it so that it ended up being really fine anyway. I also didn’t want to push my luck by demanding the subbase be prepared a certain way. My builder only gave me two options for the mix and that’s it- yet I managed to push for a custom stone ratio, have oxide added and even nominate specs like the mesh and concrete strength etc. Not only that but technically I didn’t even pay for exposed aggregate in my contract- it was compensation for an incorrect slab setout by the builder- originally I was meant to have stencilled Apropos the expansion joint to the crossover: Firstly it is personal preference- I think it is more aesthetically pleasing having a seamless transition from the crossover to the driveway. Often you see the foam sticking out above the two adjoining concrete surfaces or just generally looking plain ugly- if done properly by terminating just below the surface of the adjoining concrete and the gap neatly filled with a suitable sealant than that is fine but I didn’t trust my concreter to have such attention to detail. Secondly, I didn’t really see a great need for it- the driveways of all my family and friends don’t have the expansion joint and they don’t have any problems. And doesn’t concrete shrink as it dehydrates over time?? Wouldn’t that logically mean that the expansion join would expand- not contract?? What I meant about the rainwater is that I would rather it flow directly off my driveway and over my crossover to the stormwater. I may have overanalysed this but I believe that if there was any sort of expansion gap between the driveway and crossover that it might work like a channel and direct the water either to the sides of my driveway or seep in between the driveway and crossover itself. Sorry, I am located in Melbourne so I don’t think the concreter’s details will be of any use to you! Anyway, I am heading off to inspect the latest progress now so have a great weekend guys. Cheers Re: Best method of curing an exposed aggregate driveway? 35Mar 27, 2011 8:04 pm Great, thanks so much for all the info! Hope the final step of the job works out just as beautifully (and we get to see some pics too )! My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 36Mar 28, 2011 2:25 pm The prep worked looked all good assuming sl72, seemed enough bar chairs. Final effort looks good and some talking to help I think the final product. Road base seems to pack better than sand. I would not have dowelled the garage to the driveway, I'm not sure if isolation joint requires it? Will have to check. I would always use the plastic, just for peace of mind and very cheap. Sealant for the driveway to footpath good idea, in fact I usually remove foam on top and replace with sealant everywhere. On the subject on aggregate size in concrete not sure in regards to exposed aggregate concrete. But standard concrete mix is 20mm agg, block fill mix is 10mm. The next agg below that is 5mm which is just crusher dust or dolamite in SA. I have tried ordering 7mm agg and they just give 5mm cusher dust which is what Artisan has already mentioned. Glad it turned out well. Pulpo Re: Best method of curing an exposed aggregate driveway? 37Mar 28, 2011 7:08 pm Pulpo Sealant for the driveway to footpath good idea, in fact I usually remove foam on top and replace with sealant everywhere. Thanks My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 38Mar 29, 2011 9:11 am "Foam on top" The expansion strips, which is some sort of neoprene foam. It looks average and always wears. So I remove the top 10mm or so all the way along the joint and fill with a sealant maybe even coloured. Once the concrete has cured. Re: Best method of curing an exposed aggregate driveway? 39Mar 29, 2011 7:17 pm Thanks Pulpo. I heard that those that go rock hard over the years and look horrible are bitumen based and they are obviously not so good because they lose the elasticity. But those that remain soft (like - alegedly - Abelflex) are good. That's what I heard, not sure what is true. So, you remove the top part and just seal it with mastic? And now you got me thinking - what about putting sealant into saw cut grooves too? So that soil and seeds (/weeds) don't get in that easily? My signature is distracting people from my wise posts ... Re: Best method of curing an exposed aggregate driveway? 40Mar 31, 2011 12:14 pm Thanks Lex and Pulpo for following my thread. My Nikon’s battery went flat the day the aggregate was exposed and thereafter there was nothing interesting to take photos of as the driveway was covered with hessian and watered a good four times a day for three days. On the fourth day the driveway was saw cut and cleaned and sealed with two coats the day after that. I probably would have preferred to cure it for at least five days but I hope any increase in strength is negligible. I actually asked the concreter to let me know when he was doing the saw cuts as I wanted them strategically located but I rocked up on the fourth day to water the concrete to find a subcontractor had already cut it. This was frustrating but luckily the subbie made the cuts pretty close to how I would have liked anyway. Well that is enough catch up from me- I know you are all waiting for the big reveal so here it is, with some close-ups below... Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I know these things are subjective and I’m probably biased but I think this is the best looking exposed aggregate driveway I have seen! And I love the smaller stones too! I am in love! I do have two small little things I want to nitpick about. The first is that when the subbie sealed the driveway, excess sealant must have pooled into some of the saw cut joins and as the driveway warmed up throughout the course of the day, expanded and spilled over the finished surface in a couple places where it has bubbled- see photo below. My question is if I can do anything to fix this? I know that over time this will wear away but I want it to look perfect now! One time when I was about 15, I resealed my parent’s driveway and I did so on a day when it was perhaps too hot to do so. Anyway, within a few hours the whole job had started bubbling and blistering terribly- I am talking about 5cm diameter bubbles! I almost had a heart attack. Luckily, after a few months of vehicular traffic it pretty much disappeared, so I know that the issue I have now is not really a big deal. Apropos the sealant, the subbie used a product called NUTECH- Pave Coat. Is this any good?? Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ My second issue is that after the concrete was poured I realised I had some black stains on my crossover- from spillage of the concrete or charcoal oxide I imagine- see photo below. Is there anything I can use to get rid of it? Bleach??Thanks guys. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Last year I had a gas leak at my house. 3 days later, I have about 1 sqm of my exposed aggregate paving broken up. I am not sure how to go about getting it repaired… 0 10404 After some ideas on making our patio kid friendly . Currently we have exposed aggregate. The patio faces west and is always in sun even though it has a shade directly… 0 3566 2 430 |