The amount of cement needed for a slab depends on various factors, including the thickness of the slab and the mix ratio of the concrete. On average, you might need around 100 to 110 bags of cement (50kg each) for a 100m2 slab with a standard thickness of 10cm.

**How many cement bags are required for a 100m2 slab?,**You know that for the casting of roof slab we required nominal mix concrete like M20 mix concrete. In M20 mix concrete M is stand for mix and numerical figure 20 is stand for characteristic of **compressive strength 20N/mm2** after mixing and casting of roof slab, quantity of material in slab formation it calculated by M20 mix in which **ratio of cement,sand and aggregate is 1: 1.5 :3**

In this article we have to calculate how many cement bags are required for a 100m2 slab?. And we know M20 mix Ratio is 1 : 1.5 : 3 in which one part is cement, 1. 5 part is sand and 3 part is aggregate

**Roof slab casting** is process of laying And putting concrete mix in horizontal direction and structure over brickwork. Cast of roof slab reinforcement main bar and cross bar in distributed over shuttering areas of roof slab and then we put concrete mix of M20 or m25 grade of concrete that is known as roof slab casting.

**How many cement bags are required for a 100m2 slab?**

◆ **Given dimensions**:-

roof slab thickness ranging between 4 inch (100mm) to 6 inch (150mm) but in this calculation we take roof slab thickness is 5 inch (125mm)

Roof slab thickness =125mm = 0.125m

Area of slab = 100m2

Mix ratio = 1:1.5:3

◆ **Volume Calculation**:-

1) **wet volume**=Area × thickness of slab

Wet volume = 100m2 × 0.125m = 12.5 m3

2) **Dry volume**:-

we know that wet volume have voids and pore which filled with water and bubbles it can be remove by vibrator or compressor machine so more quantity of material is required. dry volume means mixture of cement sand and aggregates concrete in dry condition have more voids and pores that are evaporated in wet condition and volume is decrease by 54 percent in wet condition and volume of dry concrete in increased by 54% , so we can multiply 1.54 in wet volume to calculate dry volume

Dry volume = 12.5m3 × 1.54 = 19.25m3

◆ **Cement bags for 100m2 rcc slab**

Mix ratio = 1:1.5:3 ( 1 part cement,1.5 part sand and 3 part is aggregate)

Total P = 1+1.5+3 = 5.5

Part of cement = 1/5.5

in M20 mix 1 part is cement quantity

Weight of cement=1/5.5×dry volume in m3×density of cement

Density of cement=1440kg/m3

Weight =1/5.5× 1925 m3×1440 kg/m3

Weight of cement = 5040 Kg

1 bag cement = 50kg

No. of bags of cement = 5040/50

Number of cement bags are required for 100m2 slab = 100.8 bags.

100.8 cement bags are required for a 100m2 slab.

**◆You Can Follow me on Facebook and Subscribe our Youtube Channel**

**You should also visits:-**

**1)what is concrete and its types and properties**

**2) concrete quantity calculation for staircase and its formula**

**◆Now your turn:**– please like and comment it above this post, if you have any query and question about this please you will ask, thanks a”lot.