How to Figure Concrete Formula For Ready Mix

Beg your pardon Sir,

I don't understand the question.

Are you asking about a price for concrete mix formulas ( " ... price per cubic yard ... uncertain of percentages... " )

or are you asking about the cost of building a manufacturing plant for commercially selling readymix cement ( " ... ready mix concrette palnt..." ) ?

Cheers

bondjamesbond@rock.com

i need a formula to figure the amount of raw materials in yard of concrete

3CaCO_3(s) + Al₄Si₄O₁₀(OH)_8(s)→ Ca₃SiO_5(s) + Al₄Si₃O₁₂ + 4H₂O_(g) + 3CO_2(g)

The production of portland cement begins with the quarrying of limestone, CaCO₃. Huge crushers break the blasted limestone into small pieces. The crushed limestone is then mixed with clay (or shale), sand, and iron ore and ground together to form a homogeneous powder. However, this powder is microscopically heterogeneous.

It might be better to ask this question in the Civil Engineering section, perhaps? Readers knowledgeable in concrete tend to collect there.

1-2-4 refers to 1 part cement, 2 parts aggregate and 4 parts sand. This is on by volume basis. If you have the price for each then you can easily figure the price of the concrete mix.

Pursuant to my earlier post I didn´t give the arithmetics. Here it is.

1 part cement+2 parts aggregate+4 parts sand = 7 parts or 100%.

% cement = 1/7 x100 = 14.3%

% aggregate = 2/7 x100 = 28.6%

% sand = 4/7 x 100= 57.1%

thank you very much for the explanation. sir

thank you sir . may i get it on kg not in percentage,

It all depends on the job in hand but 1 part cement to 2 parts ballast normally referred to as 20mm and 4 parts of sharp sand. But other mixes are used and special additives are often used to either speed up or to retard the setting time. Some plaster-sizer, can also be added. Or hardener. You customer may well ask for a special mix.

Just curious, you referred to aggregate as "2 parts ballast normally referred to as 20mm", just what is specifically meant by that? As I understand it, the size of the aggregate, yes, of course, in a balance with the other materials, is the major determining factor in the net resulting strength of concrete.

Although your answer may be too late for me this time as I am pouring 10 concrete steps in the morning and wish to make them as strong as possible, I am pouring, by hand, 500 sq. ft. of slab next week.

It is the way we describe the aggregate that is the "stone filler" here in the UK.

Unless you have a particular specification you are required to meet knowing the mix is not important. What is important is the final strength of the concrete after 28 days. Usually on a building project you would look for 3,000 to 4,000 lb strength concrete. You might also want to consider a slump test to insure there is not too much water in the mix. Too much water means the concrete will shrink to quickly as it hydrates and will cause major cracking.

The 1:2:4 might work if you are selling to homeowners, but for significant commercial or public agency construction, an engineered concrete mix design is required that is based on precisely determined proportions of fine and coarse aggregate, water, cement, pozzolans, water reducer admixture, other admixtures and entrained air. The ingredients are proportioned by weight, but when added all together they have to equal one cubic yard in volume as this is the basis on which the mix is sold. This recipe forms the basis of the plant's proportioning of the particular mix in all quantities ordered. The mix design proportions will depend on the specific gravity and other physical properties of the local aggregates, the properties of the cement and pozzolan that is available in the area, as well as the required design properties of the mix such as compressive strength, flexural strength, durability, unit weight, air content, etc., thus the mix designs have to be worked out specific to each individual concrete supplier. Mixes are generally classified on the basis of 28-day compressive strength, i.e. 3000 psi, 4000 psi, etc. For significant projects and for any public works agencies, the concrete mix design (including the properties of the aggregates and cement) has to be submitted for approval by the design engineer for the particular project. Large concrete suppliers have their own engineering departments to prepare and test these mix designs. Smaller firms hire these services from engineering firms or testing laboratories. This all sounds complicated, but that is how concrete mix engineering works in the United States.

DA Sanford, PE

It was by the yard, now we are metric; so it is sold by the cubic metre now in the UK.

It excuses I have it in Spanish:

CONCRETO EN ZAPATAS F'C= 210 KG/CM²

Partida ---------- 05.10.21

Rendimiento ---- 25.00 M³/DIA

Código Descripción Insumo ---------- Und ----- Cuadrilla ----Cant --- Precio --- Parcial

Mano de Obra

470022 OPERADOR DE EQUIPO LIVIANO -- HH ------- 2.00 ------- 0.64 ---- 7.61 --- 4.87

470101 CAPATAZ ---------------------- HH -------- 0.20 ------ 0.06 ---- 9.28 --- 0.59

470102 OPERARIO ---------------------- HH -------2.00 ------- 0.64 ----8.44 ---5.40

470103 OFICIAL ------------------------ HH -------1.00 ------- 0.32 ---- 7.61 ---2.44

470104 PEON -------------------------- HH ------- 8.00 ------- 2.56 ---- 6.82 --- 17.46

-------------------------------------------------------------------------------- 30.76

Materiales

050003 PIEDRA CHANCADA DE 1/2 ------ M³ ------------------- 0.85 ---- 30.00 --- 25.50

050104 ARENA GRUESA ---------------- M³ ------------------- 0.42 ---- 25.00 --- 10.50

210000 CEMENTO PORTLAND I (42.5KG) - BOL ----------------- 9.74 ---- 14.58 --- 142.01

390500 AGUA -------------------------- M³ ------------------ 0.18 ---- 3.00 --- 0.55

--------------------------------------------------------------------------------178.56

Equipos

370101 HERRAMIENTAS MANUALES ---- %MO ----------------- 0.03 ---- 30.76 --- 0.92

490704 VIBRADOR CONCRETO 4 HP ----- HM -------1.00 -------0.32 ----7.00 ---2.24

491007 MEZCLADORA CONCRETO 18HP - HM ------- 1.00 ------ 0.32 ---- 11.00 ---3.52

---------------------------------------------------------------------------------6.68

Costo unitario directo por: M3 216.00

Mano de Obra = ((8h / Rendimiento * Cuadrilla) * Precio) = Parcial MO

Materiales = (Cantidad * Precio) = Parcial Materiales

Equipo = ((8h / Rendimiento * Cuadrilla) * Precio) = Parcial Equipo

Obs.- -- (8h = 8 Horas de trabajo) - - - - - (Rendimiento = Según tablas nacionales)

Hay concreto de: ------ 140 Kgr/cm² / 175 Kgr/cm² / 210 Kgr/cm²

- I hope to have been able helped, If you wish more information, send a mail by my mailbox in CR4.

could you translate that to english? please!

I must clarify my last entry. I did not, in any way what-so-ever, intend that last entry to sound or be intrepreted as to be a smart-alec response. I would truly appreciate the ability to understand the depth of your apparent knowedge of the subject matter, however, I am currently unable to fully translate all spanish into english as my understanding of spanish is limited to basic and simple conversation. If you have the time to translate that information, I will certainly expend the time to study and comprehend it.

Thank you.

1:2:4 Method refers to volume. - Quite handy, should solve your problem nicely.

Good lord.... 4 parts sand?

How about 1 cement, 2 sand and 4 stone.

http://www.cement.org/basics/concretebasics_concretebasics.asp

HOW MUCH READY MIX TO FILL A FORM 9"WX16"HX72"L 5 BAGS 6 8 ?

6 cf

12 bages required

Gentlemen: the questioning of the original writing lends just a series of simple answers which were summarised in the script by a learned gentleman from the USA.

The important issue is that as Concrete is a hydrated tobomoric gel that is formed correctly as ome would say, and have reported, from a series of materials which includes (1) Cement, (2) Aggregate, (3) Sand and then (4) water as the basic commodities it isn't clear whether the writer wants a sulphate-resisting material, a granolithic material or one with a plasticiser contained within.

From the discussions it is suggested that his potential is a traditional mixture that would be capable of being transported by a road hauled mixer and in that guise - depending upon the quantity (cubic metres required) the issue of quality assurances against a specification is not beholden to a random question but to a specific designed mix.

Having designed mixes of concrete for various purposes and various climates and environs many things are possible but the best is to leave the quality control with the right supplier who will report a mix to meet a specific design.