Concrete Structures DR Nabil Dmaidi Units of Measure
Concrete Structures DR. Nabil Dmaidi
Units of Measure Concrete : Cubic Yard Steel : Lb or tons Formwork : Square feet per contact area DR. Nabil Dmaidi
Types of Concrete construction. 1 Foundations . 2 Columns . 3 Slabs and beams DR. Nabil Dmaidi
DR. Nabil Dmaidi
Shallow Foundation Isolated Footing Combined Footing Strap Footing Raft Foundation DR. Nabil Dmaidi Continuous Wall Footing
Deep Foundation Caissons Piles DR. Nabil Dmaidi
Columns n Shapes – – n Square - Rectangle - Circular Others Reinforcement – Ordinary - Spiral DR. Nabil Dmaidi
Slabs and Beams: One-Way slabs One-Way Slab, Beam, and Girder One-Way Slab, Supported by Beams or Walls One-Way Joist Slab DR. Nabil Dmaidi
Slabs and Beams: Two-Way Slabs Flat Plate Waffle Slab Flat Slab Two-Way Slab Supported by Beams DR. Nabil Dmaidi
Estimating Issues. 1 Formwork is the largest cost item that represents 40% to 60% of concrete structure cost. Distribution of costs for cast-in-place concrete slab wall: DR. Nabil Dmaidi
. 2 Waste allowance from 2% to 10% should be added for concrete and concrete formwork. DR. Nabil Dmaidi
1. Center Line Method ” 10’ 30 Building size: 30’ x 40’ ” 0’ 40 ” 10’ 40 Calculations: 1. Length = 30’ 10” - 1’ 6” = 29’ 4” 2. Width = 40’ 10” - 1’ 6” = 39’ 4” 3. Perimeter = 29’ 4” + 39’ 4” +39’ 4” = 137” 4” 4. Volume of concrete = 137. 33’ x 1. 5’ = 206 ft 3 DR. Nabil Dmaidi
2. Sectional Method Calculations: 1. Length = 10. 833’+40. 833’ = 81. 67’ 2. Width = 27. 833’+27. 833’ = 55. 67’ 3. Perimeter = 81. 67’+55. 67’ = 137. 34 Total Linear ft 4. Volume = 137. 34’x 1. 5’ = 206 Cubic feet = 7. 6 Cubic Yards ” 10’ 30 ” 10’ 27 5. volume in CY = 206/27 ” 10’ 40 DR. Nabil Dmaidi
COST OF OTHER COMPONENTS OF CONCRETE WORK. 1 Reinforcement Steel 2. Forms 3. Concrete Mix 4. Finishing 5. Curing DR. Nabil Dmaidi
Table 1. DIMENSIONS & WEIGHT OF WELDED WIRE FABRIC DR. Nabil Dmaidi
Table 2 SIZES & WEIGHTS OF REINFORCING BAR DR. Nabil Dmaidi
EXAMPLE: How many pounds of rebar are required for the concrete floor area below? ” 6 Concrete slab with #4 rebar 15” on center each way ’ 40 ’ 20 ’ 60 ’ 30 DR. Nabil Dmaidi
Step #1: Calculate the total SF of area involved. 20'0" X 30'0" = 600 SF 30'0" X 40'0" = 1 200 SF Total = 1, 800 SF floor area Step #2: Calculate the pounds of rebar per SF of floor based on the unit spacing of the rebar at any point of intersection. Unit area: 15" X 15" = 1. 25' X 1. 25' = 1. 56 SF Unit rebar length: 1. 25' + 1. 25' = 2. 5 LF Lbs. of rebar/unit: = 2. 5 LF X. 668 lbs/ LF = 1. 67 lbs It is now known that there are 1. 67 lbs of rebar per 1. 56 SQ FT of floor area. 1. 67 / 1. 56 = 1. 07 lbs/SF of floor area. SO: 1. 07 lbs/ SF X 1, 800 SF = 1, 926 lbs of #4 rebar required. n DR. Nabil Dmaidi
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