EXAMPLE 2.7.2. ESTIMATING A SLAB ON GRADE

Estimate the concrete components of a  10 x 10m residential structure's slab on grade.

Slab on grade is less critical than suspended slabs. Most of the time, slab on grade concrete mixture is class C and 4" (max).

SLAB THK	A	B	C	A	B	C	SAND	GRAVEL
	(40KG)	(40KG)	(40KG)	(50KG)	(50KG)	(50KG)
cm	bags	bags	bags	bags	bags	bags	cu.m.	cu.m.
5.0	0.450	0.375	0.300	0.350	0.300	0.350	0.0250	0.050
7.5	0.675	0.563	0.450	0.525	0.450	0.375	0.0375	0.075
10.0	0.900	0.750	0.600	0.700	0.600	0.500	0.0500	0.100
12.5	1.125	0.938	0.750	0.875	0.750	0.625	0.0630	0.125
15.0	1.350	1.125	0.900	1.050	0.900	0.750	0.0750	0.150
17.5	1.575	1.313	1.050	1.225	1.050	0.875	0.0880	0.175
20.0	1.800	1.500	1.200	1.400	1.200	1.000	0.1000	0.200
22.5	2.030	1.688	1.350	1.575	1.350	1.125	0.1125	0.225
25.0	2.250	1.875	1.500	1.750	1.500	1.250	0.1250	0.250
27.5	2.475	2.063	1.650	1.925	1.650	1.375	0.1380	0.275
30.0	2.700	2.250	1.800	2.100	1.800	1.500	0.1500	0.300

From the area method table, class B coefficients are as follows:

• Cement  = 0.600 (40-kg bag)
• Sand      = 0.050
• Gravel    = 0.10

      

      
   
      

     


Back to 2.0. Estimating Concrete
             2.7. Estimating Concrete Slabs by the Area Method