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Ordering Ready-mix Concrete

By March 24th, 2024No Comments

There are several possibilities when it comes to purchasing concrete. You can buy the dry materials in bags, premixed and ready to be combined with water, or separately for mixing by hand or in a concrete mixer, or you can arrange to have it delivered ready for use. Ready-mixed concrete is only a feasible option if a large volume is required, and the premixed dry materials are not economical unless very small quantities are called for. For this reason, most amateur builders opt to buy all the necessary constituents individually and to mix them themselves. You will need to use a concrete mix suitable for the project you plan to tackle. This will depend partly on the nature of the project, as well as on local conditions and the quality of the materials used. For instance, a 1:3:6 cement: sand: stone mix is suitable for most garden foundations, provided a relatively fine, well-graded aggregate is available. However, the crushed stone sold in many places will result in concrete which is too stony, and in this instance, a 1:4:4 mixture is preferred. For paths, steps, and exposed slabs, it is best to use a 1:2:3 or 1:3:3 mix. If concrete is ordered ready-mixed, you will need to give the suppliers details of your project so that they can determine the required strength of the concrete and thus the kind of mix they will need to prepare for you. Mortar, made by mixing cement and sand with water, is used to bond bricks or blocks and give the structure, paved surface or edging maximum strength. Just as cement, sand, and crushed stone are mixed in different ratios for concrete, so too are the cement and sand used for mortar mixes. Generally, it is acceptable to use a 1:4 or even a 1:5 mortar mix for brickwork or paving with clay bricks. If concrete bricks or blocks are used, it is best to make up a weaker 1:6 mixture which is consistent with the building units used. Cement is a very fine gray powder used to make both concrete and mortar, and as such is one of the most important ingredients in just about every building project. Several types are suitable, but ordinary Portland cement is most popular. It is sold in 100-pound bags (and sometimes 50 pounds and 75 pounds.) Cement hardens when it is mixed with water, and it is this chemical reaction which gives concrete and mortar their strength. It is worth remembering that cement will not gain full strength if it dries out too quickly, so concrete and mortar should be kept damp while they set and cure. Bear in mind, too, that unless cement is stored away from moisture, it is likely to form lumps and become unusable. Stack it in a dry place above the ground, and use it within two to three months. Discard any cement that has become lumpy or hard. The quantity of cement needed for any project will, of course, depend on the strength of the mixture required. When using a 1:4:4 ratio, you can base estimates on 5 x 100 pound bags of cement being enough for 3 cubic feet of concrete, for a 1:3:6 mix, you will need four bags, six for a 1:3:3 mix and eight if the ratio is 1:2:3. Sand is an important ingredient in mortar, both for bricklaying and for rendering brick and block surfaces, and it is invaluable as a bedding material beneath all types of paving. Furthermore, the properties of the sand used to make concrete will have a marked effect on the final product. The best building sands are evenly graded with particles of various sizes, no bigger than 2 inches, and with 4-5% of the sand consisting of very fine material, sometimes referred to as fines. Poorly graded sand will produce concrete which is difficult to work with, while a lack of fines will result in a mixture which is hard to compact properly. While the source of the sand you are using is not necessarily a reliable guide to its quality, it is worth knowing that natural river sand is generally clean and free of clay, and pit sands are usually well graded. Crusher sand, manufactured for building purposes from crushed rocks, should be of a suitable quality for concrete work, but crusher dust is too fine. Beach sand contains shell particles and salt, and unless it has been professionally washed, should not be used. Mine- dump sand and fine, wind-blown sand from desert areas should be avoided. In addition, the sand used for making concrete should be reasonably coarse (“sharp”), while that used for mortar and plaster should be softer, with more fines. When flexible paving is laid), the sand used beneath the bricks should be coarser than that used to joint them. Coarse river sand is suitable. In some areas, suppliers add lime to sand and sell it as “plaster sand” (as it is used to make mortar for plastering or rendering brickwork), “mortar mix,” or “lime sand.” In this case, additional lime is not required (see below). Sand is sold in 100-pound (or sometimes 75 pounds) by builders’ suppliers and most hardware stores. If you want a large volume, it is best to order in bulk. The smallest quantity most merchants will deliver is half a cubic yard. Sand delivered in bulk will be dumped outside your house. If you live in a windy area, cover it as soon as possible with plastic sheeting to prevent it from being blown away. Stone, the coarse aggregate in concrete, is screened to size specially for construction purposes. In some areas natural pebbles and pea gravel are available, otherwise you will have to use crushed stone, supplied in “single sizes.” For home improvement purposes, 1/2 inch or 1/4 inch stone is best. The smallest size commonly available is 1/16 inch. While it is true that the smaller the stone, the easier it is to work with the concrete, you will need more cement for the concrete to gain the same strength, and this will also make it more costly. All quantities recommended here assume that you are using 1/2 inch stone. Like sand, crushed stone is usually available from builders’ suppliers and hardware stores that the appropriate tools and materials. Alternatively, this material may also be delivered in bulk. Your choice will depend on what sort of quantity you require. Lime is a useful ingredient which makes mortar more workable and aids water retention, and should always be included in the mix if the sand lacks sufficient very fine particles. Since it improves the plasticity and cohesiveness of the mortar, the addition of lime will make it easier to render a surface and will improve bonding between bricks and mortar. It will also help to prevent the rendered (or plastered) surface from cracking. Available in 50-pound sacks from builders’ suppliers, hydrated builders’ lime should not be confused with agricultural lime, road lime, or quicklime (calcium oxide), all of which should be avoided. Plasticizer is a popular alternative to lime in some areas. Normally sold in a minimum of 5 quarts, it is mixed with the mortar according to the manufacturer’s instructions – usually 1 fl. ounce to every 100 pounds cement.

 

Mixing concrete is a laborious task. Even if you have a mechanical mixer, you will have to shovel the dry materials into the machine. You will also have to measure the materials in batches to ensure the proportions are accurate. Use a strong, rigid container (builders bucket or a 25 quart paint can) for measuring. If you have a machine, load the stone with a little water first to prevent the mortar from building up on the blades then load the sand, and finally the cement and more water. When mixing by hand, combine the cement and sand first, either in a wheelbarrow or on a flat, dry surface. Do not mix them directly on the ground as soil, dead leaves and small twigs will almost inevitably get mixed in, and water may be absorbed from the mixture. Make a crater in the center, then add water, shovelling the dry mixture from the edges to the center. Once it is smooth, add the stone and continue shoveling. Aim for a firm, consistent mixture, neither too liquid nor too dry.

 

this is going to help you figure out the details on how to order concrete to be successful for your project it’s like ordering food if you can do that then you can order concrete yeah like beautiful amazing Awesome concrete for your project but if you’ve got tips if you’re a reader and you’ve got tips I want you to light up the comments below giving people your tips because I always learn from what you write what you have to say and what you’re all about but how do you do this how do you make this happen well the secret is to tell the people what you want we’re gonna give you tools to make this happen to make this awesome but you have to Remember Readiness producers are a lot like Master Chefs okay they create these awesome meals for you they’ve been spending spending their life doing this and they’re awesome at this so we’ve kind of got to trust them we have to tell them what it is that we want to eat and we need a checklist of Champions and at the end of this video I’m going to give you a link where you can get this all this checklist so you can fill it out for your projects and it will make You highly successful as you talk to these chefs AKA Ready Mix producers but the number one question is what are you making is it a patio that’s stained and stamped is it a retaining wall is it a driveway or are you doing a patch in something this is key for these people but they also need to know what does success look like this is a really really big big one and what do you really really need and then what is it nice to have these are questions that You have to answer for yourself what is essential for your project and then what is something you’d really like to have happen and there’s a whole list of things you can look at and number one is Aesthetics oftentimes we want our structures to look nice we want whatever we build to look beautiful what does that look like for you what what is beautiful for you how big of a deal is cracking for you on your project there are levers that these producers can pull If they know how much cracking is acceptable versus not acceptable what is the durability of the concrete how long do you want it to last you should answer that for yourself what is the strength that you need and then what is something else and if you’re like man I’m confused I don’t even know how to answer these questions keep watching videos there will be more but you need to be thinking about these things looking around figuring out what is the answer is for You how much concrete do I need this is a really really big deal and something you’re going to have to figure out usually we order them in cubic yards or cubic meters and you pretty much find the volume of whatever it is you’re pouring I’m showing a slab here you would take the length the width and the depth you would multiply them together and you would get volume now again they want these things in cubic meters or cubic yards cubic yards in America and Then there you want to also apply a safety Factor because concrete Finds Its way other places than in the forms and I at a minimum I will use a 1. 2 safety factor and if I’m not so sure about my calculations let’s say I’m pouring in the ground let’s say I’m not I don’t think my forms are super tight I may use a safety factor of 1. 6 or even higher what I’m saying here is whatever volume I calculate I’m going to add to that by multiplying by either by 1.

2 or one Point six depending on how confident I am with my Dimensions trucks that you order can carry usually the maximum between 8 to 10 cubic yards and I would never ever ever order a truck less than three cubic yards that means if you only need two cubic yards or so in a concrete project then order at least three why you don’t get good mixing action if you don’t have enough concrete inside whatever mixer that you’re dealing with but then when do I want this concrete to Show up that’s a big deal because sometimes they can’t get it to you when you need it to show up so you need to tell them that and be upfront about that and give them plenty of time and and and actual notice where do I want my concrete to show up can we get a truck to that location how will you move the concrete from the truck from wherever it needs to go for example if I have a truck they have these beautiful things called shoots on them and you can do a Ton with a concrete shooting you should try AI to use the concrete Chute as much as you can however sometimes we fill up wheelbarrows right and then we drive the wheelbarrow to wherever it goes and actually dump it out that works great if you want to do that and you have the labor to do that but you can also use something called a concrete pump this is a pump that is designed to receive Concrete in place concrete here it is in action for example this is very very Hard to get to place concrete pump is over there the truck jump dumps into the pump and then the pump pumps to wherever you need it it’s going over a house here that’s pretty cool this is what pumps can do they are awesome awesome tools but how flowable does that concrete need to be we’ll talk more about that coming up in just a second but that’s a big deal when you order concrete how long does it need to be flowable do you need it to be flowable for three hours for Example how long is it going to take your labor force to get the concrete in the molds get it Consolidated and get it smooth that is is a big deal and you need to let them know what that needs to be usually the number is around two hours or so after the concrete is mixed before it it is no longer workable two to two and a half hours but they can add chemicals to make that be three hours four hours and five hours they can do it they have to know that that’s what you Need you have to tell them that how will you finish the concrete that is a big deal and and that’s something that you need to think about we’ll have some more videos on that coming up and will the concrete get wet and freeze that is a big deal because you have to order air and train concrete if this is going to be a true statement and then finally how much does it cost that’s like the final question I you got because they need to know all this other stuff first before They can ever know how much and quote you what is the concrete going to cost and there may be all kinds of things in there they add about delivery stuff whatever that’s fine just figure it out how much does it cost figure all that out and there the more you want this concrete to do the more it is going to cost you and that’s no different than if I order a seafood Feast like this it’s I’m going to expect it to cost more than if I order a cucumber salad and I’m not Saying ordering a cucumber salad is the way to go I’m just saying they’re going to be different prices you have to realize that you have to understand that that’s just part of concrete that’s just how it works but let’s learn some concrete lingo this is important lingo you need to understand this when you order concrete and and the first one is flow ability how flowable is the concrete and we talk in a term called slump all right slump is actually a test And they may actually not run this test on your site but it’s like this they have this cone that they fill up in a standard manner they actually pull that cone up it’s got a false bottom on it and or an empty bottom on it and as they lift it up they measure how much does it fall all down for example the beginning it started out up here and then after they pull it up how much did it fall down right and the more it falls that means the more flowable it is so if you Have a low slump number not very flowable a high slump number very very flowable concrete right so let’s just look at it in numbers like this and I’ve broken up up into ranges this is just my choice this does not mean it’s the best choice for your project between about zero to three inches that’s usually placed by a machine a slip form paver type applications most DIY people do not do this most people in general do not do this but between three to six inches is Where you can get hand placed concrete that um that that is a good number and between seven and nine inches is when you have really congested placement as in you need extremely flowable concrete and so there you go I like to order about a six inch slump right when I’m pumping or when I’m doing hand placement as I get higher than that it gets more expensive and also I’m not sure the quality of the concrete is as good as when you ride around in that six inch Slump number and we can talk more about that if you want but that’s not the only term we also talk about strength sometimes and when we say strength of concrete we’re talking about compressive strength loading it down from the top and again no one may do these tests on your site but what that means is if I take a mold like this and I fill it up in a standard Manner and then I take my ID mold it after it’s hard and I take it to a hydraulic press and I break it what Is the strength of that concrete and this is usually done at 28 days doesn’t have to be but most specifications are based on a 28 day strength and here are again our three different ranges this does not mean these are the only ranges out there but I’ve broken them out into some simple categories here to 3000 psi would be interior exposure that means concrete that is not exposed to the weather inside of a building then there’s 4000 PSI that’s external Exposure and again if you’re in a very very benign environment then maybe you can get away with something less than four thousand but most of the time you need about 4 000 PSI for external exposure and for structural concrete or higher performance concrete you may want 5000 PSI now there’s some people out there that think stronger concrete is is better that is not necessarily true it depends what you want it to do but let me give you an expert trick right now Something that I think is very very powerful and cool and you should think about using it is I don’t order concrete by strength I think strength is a total misnomer I think we’re way too obsessed with strength and I’ve talked about that on other videos I order my concrete by water to cement ratio the strength will be great it will be what it needs to be if I have a project where I have to have a strength then I will specify it but I oftentimes order concrete by water Cement ratio water cement ratio is the mass of the water divided by the mass of the cementitious the binder okay any any cement and any um fly ash or slag um that is inside that concrete and the here are the categories we talked about before three thousand four thousand five thousand and I do it like this if my interior exposure I’m at a 0. 50 or higher if I’m an external exposure I want a 0. 45 water cement ratio and if I want structural concrete higher strength Concrete higher performance concrete then I may order a 0.

42 or lower you would be be careful here be careful I would never ever use a water cement ratio greater than 0. 55 I’m not saying you can’t do it I just wouldn’t do it and I would never order a concrete with less than a 0. 40 and so you got to find where you’re at in that range and what’s that what’s best for you my rule of thumb if I’m using internal concrete I want a .

50 if I’m using external Concrete then I want a 0. 45 and I’ll vary from that but this is the rule of thumb this covers about 80 to 90 percent of what I may be doing so how do I pick a my supplier how do I figure out who am I going to choose well a lot of people just use cost and and and I would like to say is there another way out there is there another way to think about this because who are their clients do they do work for cities states Departments of Transportation do They do it for high-end businesses um or do they do they always just do homes okay that that’s something that you need to ask have they done similar projects to what it is that you’re wanting to do especially if you’ve got something that’s kind of unique or strange do they have experience in it what warranty do they provide on their work well they may not or they may but if you don’t ask then you will never know and you need to get these Expectations figured out up front what is their Quality Control process quality control that’s like what regular testing do they do to make sure that they’re giving you great great concrete or the concrete that you ask for day in and day out it’s kind of like testing the soup right chefs don’t make soup without testing it people shouldn’t make concrete without testing it as well do they optimize their aggregate gradations now this is a this is a bonus question This is a little higher level question but you should ask them and just see what they say do they act like you’re crazy do they act like they’ve never heard of it and then you might even want to ask them and say have you ever heard of the tarantula curve or do you use a tarantula curve now that’s really bonus question okay but the best ones out there they’ll have heard about it and may even be using it and do they watch my videos The ultimate test as if they know what it is they’re doing a lot of concrete producers do and so you should ask them and if not let them know about my channel right and who in the end do you think will do the best job for you that is the most important question of all and you got to trust the chef after you’ve chosen who you’re going with trust the chef right whoever they are you know just go with them believe in them get behind them and make it happen

 

George Gitau

Meet George, an advocate for traditional craftsmanship. I will provide you with educational content, techniques and ideas for your next garden and home improvement project. Together, let's create beautiful spaces that are not only beautiful but also functional

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