Kongiri nesimbi
Concrete calculator
This calculator works out the cement, river sand and stone for concrete: a floor slab, a strip footing, columns, beams, or any volume you already know. Choose the element, enter its size and how many there are, and pick the mix.
Zvaunoda
Calculator iyi inoverenga nhamba mubrowser yako, izvo zvinoda kuti JavaScript ivhurwe. Nzira iri pazasi inoratidza kuti ungazviverenga sei nemaoko.
Fungidziro dzekuronga nekuita bhajeti. Huwandu chaihwo hunoenderana nenzvimbo nebasa, saka bvunza muvaki wako usati waodha.
Concrete in Zimbabwe is made with river sand, which is coarse and clean, and crushed stone, usually 19 mm. The mixes here are the traditional volume mixes used on site, from a lean 1:3:6 for blinding up to 1:1.5:3 for reinforced slabs and columns. Where an engineer has specified a strength (a 25 MPa slab, say), follow their mix: a volume mix on site is an approximation of a design strength, not a guarantee of it.
The figures include water at a water to cement ratio of about 0.5, which is about 25 litres per bag. Too much water is the most common reason site concrete is weaker than it should be.
Mashandiro ayo
- Wet volume is the element size multiplied out (length × width × thickness, and so on), times how many there are.
- Dry volume = wet volume × 1.54. The sand fills the gaps between the stones and the cement fills the gaps in the sand, so far more dry material goes in than concrete comes out.
- The dry volume is split by the mix ratio. Cement is taken at 1,440 kg per m³ (28.8 bags of 50 kg), river sand at 1.6 tonnes per m³ and stone at 1.5 tonnes per m³.
- Water is 0.5 litres per kg of cement.
Zvainofungidzira
- Reinforcement and formwork are not included; the steel calculator does the bars and mesh.
- Volume batching with a wheelbarrow or gauge box, not weigh batching.
Mibvunzo inowanzobvunzwa
How many bags of cement in a cubic metre of concrete?
About 6.5 bags for 1:2:4 and about 8 bags for 1:1.5:3, using 50 kg bags. A lean 1:3:6 needs a little under 5.
What mix should I use for a house slab?
A ground-floor surface bed is commonly 1:2:4. A suspended slab, columns and beams are structural and should be cast to the engineer's specification, usually 20 to 25 MPa.
Why river sand for concrete?
Concrete strength comes from a clean, well-graded mix of particles. River sand is coarser and has less clay and silt than pit sand, which would weaken the bond with the cement.
Unoda huwandu chaihwo hwepurani yako?
Calculator inoshanda nemadziro rimwe kana slab imwe panguva. Bill of quantities inoshanda nemadhirowingi ako chaiwo uye inoverenga zvese, ndizvo zvinoshandiswa nevavaki kuisa mitengo uye zvinokutadzisa kutenga kaviri.