To determine the amount of concrete per batch, where the nominal maximum size of the aggregate does not exceed 38 mm.
Balance – 0.01 kg. sensitive to
Tamping bar – length 38 cm, weight 1.8 kg
Cylindrical Mold – Dia=250mm, Height=280mm, Capacity=0.01m3
Step by step procedure to calculate the amount of concrete per batch
Step-1 (Measuring the Volume of the Cylinder)
- Fill the cylindrical mold with water at room temperature so that no meniscus is present above the rim.
- Weigh the water required to fill the cylinder.
- Divide the weight of the water required to fill the mold by the unit weight of water, i.e. 1000 g/L. This will give the capacity (ie volume) of the mold. let it be “V”1“M. in3,
Step-2 (Calculation of Density of Compacted Concrete)
- Fill the fresh concrete into the mold in layers about 5 cm deep and compact each layer by giving 60 strokes of the tamping bar, distributing it evenly over the cross-section of the mold.
- Tap the outer surface of the cylinder 10 to 15 times so that no air bubble is visible on the surface of the compressed layer.
- After compacting the concrete, use a flat cover plate to fill the mold to an even level.
- Wipe off all excess concrete from the outside surface and weigh down the mold with compacted concrete. Find the weight of the concrete by subtracting the weight of the mold from the total weight. W it. let be1,
- Calculate the weight per cubic meter of concrete (ie the density of concrete) by dividing the weight of the fully compacted concrete in the mold by the measuring capacity (ie W).1/v1,
Weight per cubic meter of concrete, W = W1/v1
W = weight of concrete per cubic meter (ie density of concrete), kg / m. In3
woo1 = Weight of fully condensed concrete, in kg.
v1 = volume of the cylindrical mould, m . In3,
Step-3 (Calculation of Concrete Quantity Per Batch)
Use the following formula to calculate the amount of concrete per batch
V = [(N*50) + Wf + Wc + Ww] / woo
V = Volume M. In3 of concrete produced per batch
N = Number of 50 kg bags of cement per batch
wooF = the total weight of the total weight per batch in used condition.
wooC = Total weight in kilograms of coarse aggregate per batch in used condition
woowoo = total weight in kg of water of the mixture mixed in the batch
W = Density of concrete kg/m. In3 (as calculated in step-2)