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20

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 ...


18

Looks like effloresence to me, which itself is not harmful, but possibly a symptom, mainly of water movement; I would check perimeter walls for further signs of water infiltration, and make sure water movement outside is properly being handled, i.e. gutters, grading.


11

Several things affect the final weight of concrete. Concrete has many different densities based on its composition. Standard "ready mix" concrete is often engineered for structural strength of 3000psi. Since concrete is not this strong when it is first poured, a standard was created for when to test concrete. This standard calls for the strength to be ...


9

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 )


8

You could make a pretty simple test to get almost exact data for your situation. My guess is that you are planning to use the pre-mixed stuff in the bags that you buy from the big box home store. Spend less than ten bucks and get a bag. Weigh it before opening the bag. Then mix up a batch according to the recipe on the bag and pour the mix into some random ...


8

Efflorescence, salts rising to the surface due to presence of moisture. Common in cementitious materials where water is present. You can wash it away with mild HCL solution but the stains will remain. Not much to worry about here. On structural masonry over long periods of time there might be a concern as it could be indicative of structural integrity ...


7

Mortar is not waterproof. However, there are products that can be applied to mortar (and other concrete materials), that can make the mortar waterproof.


7

Well, you have to mix lime and sand. If you want concrete you add rocks. So you will need to find a source of lime, limestone will work. The ancient Romans used volcanic ash. Powderize the limestone and cook the heck out of it, like burn it. You will need a furnace that gets to like 2000°F. Then mix it with a bit of water and some sand. Probably cheaper ...


6

According to my research, about 95% of the water used in the concrete mixing process will be in the final result, so you basically need to directly calculate how much you want the plates to weigh by adding the weight of the concrete and water together. Sites suggest that you'll need about 10% more concrete than calculated just to be safe. Standard ...


5

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 ...


4

Yes, mortar is waterproof. It is "relatively unaffected" by water "under specified conditions". Water-proof or water-resistant describes objects relatively unaffected by water or resisting the ingress of water under specified conditions. –Waterproofing, Wiki However, anything claiming waterproof is likely a long way away from being watertight or ...


4

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 (http://milspecanchors.com/shop/accessories/6x6-post-anchor-heavy-duty-cast-aluminum-structural-...


4

You can neutralise the acid by mixing with alkali. However, be careful. You will need quite a lot of something like baking powder. Or if you have any left over - cement powder. Add a small amount to the acid - it will foam and release gas (Carbon Dioxide). Don't add too much at once or the bucket will overflow and you will get acid everywhere. Keep ...


4

The wall may have been built that way but I doubt it, the wall may have shifted over the years and is stable now. The only way to know is to drop a plumb bob from the upper decking just in front of the wall and measure the gap at top middle and bottom. Mark the spot or leave a nail or screw in that location and Mark the wall at the 3 points so you can ...


3

Adding different amounts of water will change the strength of the concrete. So you probably don't want to change that. I don't know if there is a way to calculate the final weight, but the easiest thing to do is probably to make it heavier than needed, and sand or chip away at it until it is the exact weight you want.


3

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 ...


3

Rather than try to shape the slab so it conforms to the pipe, cut the slab slightly wider and deeper than the pipe. Mix a loose batch of cement, pour into slab cut, and embed pipe into concrete.


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

Patching rarely works out, structurally or aesthetically. If you want the cost effective remedy then go with smashing it up and installing properly supported decking material. This will likely involve installation of footings for support joists. A close look at the pictures reveals an underlying problem related to movement of the porch foundation, that is ...


3

Efflorescence, salts... you'll also see it on brick faces. Rookie concrete workers. Was your basement floor poured in winter? They add more "chemicals" into the mix, keep it from freezing, keep it flowing, not hardening as fast. Those "salts" leach up through the concrete. It is what makes an epoxy floor POP up! Fellows wit experience, can mix a batch, ...


3

You can, and should wait until the overnight temperature is above 40. Working with any masonry products in low temperatures brings a bunch of complications you don't need. If you don't mind a slight color mismatch, like the existing repair above the chipped area you can fix it yourself. If you want an invisible repair you may want to consult a mason. In ...


3

The time from when the cement, water, sand and particulate are mixed till the time the mix should be in your forms is limited. That is a primary reason that a delivery truck can only stay at your lot for a max time (they have a secondary consideration of keeping the truck on the road delivering other jobs but many companies may stay longer for an overtime ...


3

PVC pipe like that is relatively easy to repair. The general concept is that you cut out the bad section including any fittings and then install new pipe and the necessary fittings to join back to the part where you cut it out. If these lines carry water under pressure then you will need to make sure to shut off the water supply and ensure that the area ...


3

I would suggest using a colored sealer instead of paint. It is available in several color options. Sherwin Williams is just one of the brands I searched. The sealer will penetrate the concrete so minor surface damage will be less noticeable.


3

This is the remnants of a natural gas or propane grill, gas heater, or perhaps a gas lamp. The flared tubing fitting and old control valve stem are the giveaways here. Look around the structures adjacent to the yard for signs of a pipe with a valve for which you cannot ascertain a purpose, so you can at least try to confirm that any leftover fuel supply ...


3

Hydraulic cement sticks to wet fine, but you may need to abrade the surface to get to clean concrete, as it won't like a greasy, dirty or otherwise befouled surface. However, what I would actually do (and have actually done) to direct water on a concrete floor is to use a diamond saw to cut a small channel into the surface - much neater and tidier - also ...


2

Best is to keep it damp "forever." Design strength for most concrete is based on 28 days at 21C/70F. The early part of the cure is the most critical. Time is doubled at 50F/10C and reduced at higher temperatures - so long as it's kept damp. Covering with damp cloths/burlap/sacking and then covering that with plastic can help to keep it damp longer (from a ...


2

This doesn't look like foundation damage. This is a settling of the pathway around your house. Good news is that it doesn't look like serious problem, at least from what I can see from the picture. This issue should be fixed because it will only get worse, and then rain water will go under you foundation and that could be a problem. You should demolish ...


2

When I redid my fence 2 years ago, I went with PostMaster metal posts (http://contractors.masterhalco.com/Contract.nsf/woodpostmaster). They weren't substantially more than a good PT post at Home Depot. You can also easily wrap them with a picket so you don't see metal. I dug the holes about 30" deep, then just drove the posts into the dirt til they were ...


2

I just got this response from Belle. Yes you would be able to use EP80/90. We recommend to change the oil every 6/12 months but this is dependant on use.


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