concrete structures - an-najah national university：混凝土结构-纳贾赫国立大学

DR. Nabil Dmaidi,Concrete Structures,DR. Nabil Dmaidi,Units of Measure,Concrete:Cubic YardSteel:Lb or tonsFormwork:Square feet per contact area,DR. Nabil Dmaidi,Types of Concrete construction,1.Foundations2.Columns3.Slabs and beams,DR. Nabil Dmaidi,DR. Nabil Dmaidi,Shallow Foundation,DR. Nabil Dmaidi,Deep Foundation,Caissons,Piles,DR. Nabil Dmaidi,Columns,ShapesSquare - Rectangle - CircularOthersReinforcementOrdinary - 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,Two-Way SlabSupported by Beams,Flat Slab,Waffle Slab,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,Calculations:1.Length = 3010” - 16”= 294”2.Width = 4010” - 16”= 394”3.Perimeter = 294” + 294” + 394” +394”= 137”4”4.Volume of concrete = 137.33 x 1 x 1.5= 206 ft3,3010”,30,400”,4010”,Building size: 30 x 40,DR. Nabil Dmaidi,2. Sectional Method,Calculations:1.Length = 10.833+40.833= 81.672.Width = 27.833+27.833= 55.673.Perimeter = 81.67+55.67= 137.34 Total Linear ft4.Volume = 137.34x1x1.5= 206 Cubic feet5.volume in CY = 206/27= 7.6 Cubic Yards,3010”,2710”,4010”,DR. Nabil Dmaidi,COST OF OTHER COMPONENTS OF CONCRETE WORK,1.Reinforcement Steel2.Forms3.Concrete Mix4.Finishing5.Curing,DR. Nabil Dmaidi,Table 1.DIMENSIONS & WEIGHT OF WELDED WIRE FABRIC,DR. Nabil Dmaidi,Table 2SIZES & 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,20,60,40,30,DR. Nabil Dmaidi,Step #1: Calculate the total SF of area involved.200 X 300 = 600 SF300 X 400 = 1 200 SF Total= 1,800 SF floor areaStep #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 SFUnit rebar length: 1.25 + 1.25 = 2.5 LFLbs. of rebar/unit:= 2.5 LF X .668 lbs/ LF = 1.67 lbsIt is now known that there are 1. 67 lbs of rebar per 1.56