2.7. ESTIMATING CONCRETE SLABS BY THE AREA METHOD

With the aid of a table, the area method for estimating concrete can be used easier than volume or weight method. In this topic, slab does not necessarily mean the horizontal pavement but also vertical slabs like concrete walls.

Procedure:

1. Determine the area of the slab.
2. Using the table, identify the proportions of cement, sand, and gravel, after figuring the required concrete class and the thickness of the slab.

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

Example 2.7.1. Estimating a concrete road pavement

Example 2.7.2. Estimating a slab on grade

Example 2.7.3. Estimating a concrete wall

Example 2.7.4. Estimating an irregular pavement

Back to 2.0. Estimating Concrete