Reinforced Concrete Deck Concrete Mix Ratio

Its mix ratio is not static; it's also a dynamic adjustment process.
For example, the silt content of the sand you use can affect the amount of cement needed, as well as whether the sand gradation is appropriate; the type of aggregate you use is river stone or crushed stone, its silt content, and whether the gradation is a mixed gradation or a single particle gradation; the brand and type of cement you use, whether it's a 32.5 or 42.5 model; do you use mechanical mixing or manual mixing for stirring?

Water source, whether it's potable water or river water, the water-cement ratio...all these factors affect and determine the amount of cement used. Besides these, there are many other factors to consider. Therefore, the concrete mix ratio for engineering use must be tested in the laboratory using the actual materials to be used on the construction site.

Different brands of cement vary in volume stability and early strength, among other indicators. Failure to conduct tests and trials during construction can lead to significant cement waste or severe quality accidents due to substandard concrete strength.

For self-built farmhouses or minor repair projects with limited construction volume, increasing the cement dosage can be an option. Mix the C30 concrete as C35-C40, since the volume is not substantial, it's acceptable to add the savings from the concrete mixture trial cost to the concrete itself. However, it's also advisable to seek guidance from an experienced tradesman.

Below is a list of concrete mix proportions I have used in the past.

C15 Cement 330, Sand 619, River Stone 1315, Water 160 (27.5% cement)

C20 Concrete 330, Sand 618, River Stone 1315, Water 167 (32.5 Cement)

C25 Cement 390, Sand 561, River Stone 1309, Water 170 (32.5 Cement)

C30 cement, 430 kg; Rodent 530 kg; River stone 1309 kg; Water 170 kg (32.5 cement)

The above data is only the mix ratio determined by the construction materials I used at that time. If the project is to be used, a test mix ratio must be conducted, and the actual mix ratio for construction should be adjusted according to the water content of sand and stone at the construction site.