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13

Concrete is a mix of large aggregate, small aggregate, and cement (a 4:2:1 ratio is a good approximation - though designed mixes will be more calculated than that). The size of the large aggregate isn't particularly important, unless you are working in very tight spaces or around reinforcement, in which case you want suitably small aggregate. In this case ...


7

With regard to using wood posts in concrete: Note that any water that drains down the side of the wood post will drain through to the subsoil. The post should be in a collar, not a cup... (Feel free to integrate into the answer of @sch )


5

It is not good practice to bury wood in concrete as you depict. Best to use metal anchored in the concrete and attach the wood to the metal. Your result will be inevitable rot and failure, probably not before the kids outgrow it but maybe. Something like this ...


4

Reducing the amount of Portland Cement in the concrete will reduce its strength. That is, adding rocks to an already-blended mixture of concrete will reduce its strength over the same mix without the rocks. If this weren't true, they would just add rock to the original mix, since rocks are way cheaper than Portland Cement. The other issue, as John ...


3

It is pier size that matters. My God, yes to the above answers if you were building a very serious structure. Yes less Portland the less PSI. 6 sack Portland cement is about 4000 psi. You can drive a 10,000 pond bull dozer on it all day. % sack which you can buy at Home Depot is about 3000-3500 psi. It is pier size. Dig a 12" x 2' and add some of your rocks, ...


3

Ooooh, fiber mesh. Proprietary crap like that is how sellers pad their profit margins. It is like when car dealers sell you "undercoating". The weight of the vehicle and thickness of the concrete does not matter. What matters is the subsurface. If the subsurface is solid 1" (inch) of concrete will support a cement truck. If it is not, it could break under ...


3

What kind of liner do you propose to use? Seems to me that any liner that I can think of would rip easily with the rigor of mixing the concrete. I have used one of those heavy duty wheelbarrows that has a plastic tub on it for mixing concrete. It was surprisingly easy to wash out as compared to a metal wheel barrow.


3

Microballoons. Tiny glass or phenolic bubbles. They are the standard product for mixing into epoxy when you need a paste. Should be available at any place that caters to boat repair. Plugging the hole with masking tape or similar may also work perfectly well in this case. If you can arrange to hold the bolt in with pressure, you could also use a large ...


2

Sure, that's fine. The rubble will act as aggregate, and new concrete will bind the it all together into a monolithic mass. This was standard practice back in the day, in fact. And castle walls were built this way too. You'll be just fine; just try to smash the old steps into smaller rather than larger pieces.


2

I resurfaced my concrete patio with a combination of Mapei products. It worked out great. Concrete surfacing systems are really unforgiving if you make a mistake selecting and applying the products. To make sure you are on the right track you definitely should ask your Mapei rep to recommend the correct products and techniques - that's what I did. I've ...


2

Spray container with a quick shot of wd40 works like a charm and my fathers been doing it for 30+ years he also sprays his trowels.


1

Instead of temporary forms, make permanent ones. Cut a 2x4 in to a wedge shape, apply a thick bead of silicone down the middle of the underside, and screw them down with masonry screws. Once the silicone sets, fill your forms with cement. Now you have a nice level permanent pad for your machines.


1

You'd want to use a products like this: http://www.homedepot.com/p/Quikrete-1-qt-Concrete-Crack-Seal-864000/100318507 It'll be hard to get concrete mix into such a small hole without leaving a void. This crack sealer is designed for smaller holes & cracks. Documentation here: http://www.quikrete.com/PDFs/Projects/RepairingConcrete.pdf


1

I agree with Tyler Durdens advice,with one important addition. Don't lay your patio directly on gravel. Assuming your patio is about 75-100mm deep, gravel on its own will not offer enough support, and eventually, cracks will appear due to subsidence. A much better solution would be to "layer" your foundation in order of aggregate size. Lay a layer (or two) ...


1

Concrete is one of the more tricky trades. Ground prep is the #1 important thing. Proper base thickness, and proper compaction are key. #2 is a proper mix; too wet and too much water (typical) weaken the concrete. Instead of fiber mesh, use plasticizers to allow the concrete to run better but without adding too much water. And finally proper finishing ...


1

You need the concrete to be strong at the bottom and next to the post, otherwise it just needs to be heavy. So put some concrete in the bottom, the rocks round the sides and fill the center up with concrete. You can even brace the post with a few bricks on two sides of the post least most of the post clear, then fill round with concrete. The ...


1

People have bound stone in concrete since...well, since they started using concrete. I don't think adding rock is a bad idea in principle but it matters what sort of rock you are adding. Adding round igneous rock isn't as good as adding broken igneous rock but both are better than adding sedimentary or aggregate rock. I'd support using a metal or plastic ...


1

I don't think you can cover it with a resurfacer. Spalling concrete will likely just keep spalling, so any resurfacing material you put on will just flake off along with the concrete. Do you live in a cold climate? If so, avoid using de-icers (salt) on concrete. This makes the problem worse. I think your idea of deck tiles is a good one. Though it may ...


1

Those are not cracks. It is where the concrete was poured and had a chance to set for a while, perhaps while another part of the foundation was being poured. The concrete chute or hose then returned to the area in question, and resumed pouring, allowing the coarser aggregate to show at the joint. It may also be a cold joint, where concrete was started, ...


1

John, you undoubtedly found a solution some years ago, but this kind of situation will likely surface again for other DIY's. I'd suggest considering using Sonotubes, if they are readily available. Yes, they typically are used for making tall columns (I've used them for building 9 foot high, 1 foot diameter pillars in an earlier backyard of mine), but they ...


1

If built correctly, an asphalt driveway should last nearly as long as one paved with concrete. Concrete driveways are durable, but they are subject to frost heaves. They also need to have regular control joints added which can lead to substantial cracks appearing that are big enough to have weeds grow in. The look of a concrete drive can basically be ruined ...


1

Concrete will provide a much better, long-lasting driveway, if it is properly built. For both types of materials, subsurface preparation and drainage are critical and are similar. Concrete will be more expensive both because there are fewer people that do it, it involves more work because forms must be built, and the material is more expensive.


1

Sure you can have one, no one is going to arrest you for putting it in. However, concrete has a few distinct disadvantages in the north, most notably it is brittle so any heaving caused by freeze/thaw cycles will cause large cracks and there chances of a lip developing (a trip hazard unless ground down) are high. The only way to prevent this is to make the ...



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