Construction Fundamentals

1. Engineering Materials Construction Fundamentals 1

3. Aggregates Sieve No: number of holes in a lineal inch Cobbles: > 3� Coarse gravels: 3� � �� Fine gravels: �� � No. 4 Coarse sands: No. 4 � No. 10 Medium sands: No. 10 � No. 40 Fine sands: No. 40 � No. 200 Silt/Clay: < No. 200

4. Aggregate Properties Soundness: resisting weathering Abrasion: a wearing away by rubbing or scraping Permeability: ease with which water flows through an aggregate�s void

5. Gradation The distribution within the range covered: Well graded: sizes of particles are in approximately equal amounts Uniform: a large % of the particles are of approximately the same size Gap-graded: most of the particles are of a large size or a small size with very few particles of an intermediate size

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7. Concrete Mix Properties Mix design: aggregate, cement, admixture, strength, color NRM concrete weighs 150 lb/cf = 4050 lb/cy Hydration = Portland cement + water The heat of hydration: a critical factor in mass concrete

8. ASTM Types of Portland Cement Type I: Resistant to naturally occurring chemical attack Type II: Resistant to moderate sulfate attack Type III: High-early strength Type IV: Low heat for mass concrete Type V: Resistant to high sulfate attack

9. Concrete Mix Properties � Cont. The w/c ratio: controls the compressive strength; excessive water reduces strength, durability, hardness, resistance to chemical attack, and resistance to freeze-thaw Air-entrainment: adding microscopic bubbles of air uniformly throughout the mix, improves resistance to freeze-thaw and to scaling caused by salts used for ice removal

10. Concrete Reinforcement Use Concrete Reinforcing Steel Institute (CRSI) Manual of Standard Practice for placement methods for bar supports and rebars Type of steel: grade, smooth/deformed, type of coating Grades 40 (yield stress=40Ksi), 50, 60, 75 Size: #3 to #14 Diameter of bar #8 = 8/8 = 1� Supports: chairs, spacers, bolsters, wires,...

11. Reinforcing Steel 11 Minimum concrete cover over rebars: 3� for concrete cast against earth and bottoms of footings 2� for concrete surfaces exposed to the weather 1.5� for the top, bottom, and sides of beams and girders �� for the top and bottom of slabs

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15. Welded Wire Mesh 15 Designation: WWF 6x6 W4.0xW4.0 6: longitudinal spacing in inches 6: transverse spacing in inches W4.0: cross sectional area long. (In2 . 100) W4.0: cross sectional area tran. (In2 . 100)

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18. Accessories: 18 Expansion joint covers (aluminum/bronze) Expansion joint filler (asphalt-impregnated fiber) Water stops (rubber/neoprene)

19. Concrete Finishing 19 Floors: hand or machine troweled, wood float, broom, sealer Walls and ceilings: bushhammered, exposed aggregate, rubbed, sandblasted �

20. Curing 20 Cement hydration requires time (3 to 14 days), favorable temperatures, and moisture. Curing options are: leaving forms in place sprinkling spray mists moisture retention covers seal coats (curing compound) Hot and cold concreting �

21. Transporting Concrete 21 Truck chutes Buggies Crane and bucket Conveyors Pumps

22. Precast Concrete 22 Concrete members that are cast in separate forms and then placed in the structure. Advantages over cast-in-place concrete: faster erection during all weather conditions consistent finishes because of controlled environment at the plant sophisticated finishes and shapes may be produced in a plant for longer spans prestressed concrete is used, either pretensioned or posttensioned.

23. Masonry Properties Masonry Design and Construction have been established by: International Masonry Institute (IMI) Brick Institute of America (BIA)

24. Concrete Masonry Unit 24 The standard modular face dimensions of the CM units are 7 5/8" high and 15 5/8" long. Thicknesses available are 3, 4, 6, 8, 10, and 12 inches (nominal, actual dimensions are 3/8"less). A 3/8" mortar joint provides 8"x16" face dimension Heavy weight versus lightweight units

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27. Bricks 27 Brick is a solid masonry (when its core unit is less than 25% of the cross sectional area) made of clay. Bricks are classified by: kind (common or face) size texture or finish on the face

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29. Brick Positions and Patterns Stretcher position: horizontal, the longest- narrowest side facing the front of the wall Header position: horizontal, the shortest- narrowest side facing the front of the wall Rowlock position: used on window sills Soldier position: vertical, the longest- narrowest side facing the front of the wall Sailor position: vertical, the largest side facing the front of the wall Shiner position: horizontal, the largest side facing the front of the wall

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33. Types of Masonry Walls Concrete block wall Solid brick wall Composite wall Insulated cavity wall (where a max resistance to rain penetration is desired) Veneer masonry wall (non-load bearing wall for decorative purpose)

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36. Masonry Mortar Masonry mortar usually consists of Portland cement, mortar sand, and hydrated lime. Lime: improves workability, elasticity and water retention Sand: decreases the shrinkage of mortar minimizing cracking Retempering: addition of water to mortar mixes that have lost water, reduces the strength, but increases the bond strength

37. Types of Mortar 37 ASTM Types of Mortar Type S � medium high strength, used where high bond strength and lateral strength are needed (foundations, basements, exterior walls, interior load bearing walls, reinforced walls) Type N: medium strength, used for exposed masonry above grade

38. Horizontal Masonry Reinforcement 38 Steel reinforcing is placed continuously in the mortar joints to minimize shrinkage, temperature, and settlement cracks in masonry and to provide resistance to shear.

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40. Wall Ties 40 to tie the outer wythe with the inner wythe type of ties

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43. Reinforcing Bars 43 Vertical reinforcing (to provide lateral support) Horizontal reinforcing in bond beams

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45. Bond Beam � Control joint Bond Beam: continuous cast-in-place lintel blocks with reinforcement that run around the perimeter of a building or between control joints. Control Joints: vertical joints that separate walls into sections and allow freedom of movement

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47. Coping 47 Covers the top course of a wall to protect it from the weather. coping block stone precast concrete

48. Sills 48 members at the bottom of window or door openings brick stone precast concrete

49. Lintels 49 steel precast concrete lintel block with rebar and filled with concrete

50. Structural Steel The American Institute of Steel Construction (AISC) The Steel Joist Institute (SJI) The Steel Deck Institute (SDI)

51. ASTM Structural Steel Specifications 51 Plain carbon steel A36 (Fy=36 ksi) High Strength low alloy steel A572 (Fy=42 to 65 ksi) Corrosion resistant high-strength low-alloy steel A242, A588 (Fy=42 to 50 ksi) Quenched and tempered A852 (Fy=70 ksi), A 514 (Fy=90-100 ksi)

52. BCN 5618 52

53. BCN 5618 53

54. Standard Cross-Sectional Shapes 54

55. Standard Cross-Sectional Shapes 55

56. Standard Cross-Sectional Shapes 56

57. BCN 5618 57 Metal Joists (open web steel joists) Metal joists are prefabricated lightweight trusses that are available in different series: J and K series- spans to 56� (short span) LJ and LH series � spans to 96� (long-span) DLJ and DLH series � spans to 144� (deep long-span) Designation: 12K4 12 = depth in inches K = joist series 4 = designation within series (the higher the number, the heavier the joist)

58. BCN 5618 58 Open web steel joist

59. BCN 5618 59 Joist Girder

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63. Properties of Wood and Lumber Grades 63 Sawn Lumber: Wood members that have been manufactured by cutting a member directly from a log. Design values for sawn lumber depend on species group grade Load duration moisture content Size

64. Grading Structural Lumber 64 Lumbers are graded based on size and number of growth (strength-reducing) characteristics they have (knots, checks, shakes, splits,...)

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66. Grading Structural Lumber 66 Visually Graded

67. Grading Structural Lumber Visually Graded WWP: Lumber Grading Agency 12 : Mill Number SEL STR: Lumber Grade DOUG FIR-L: Lumber Species S-GRN: Moisture Content Machine Stress Rated 1650:Nominal Bending Stress, psi 1.5E: Modulus of Elasticity, million psi 67

68. Sizes Categories 68 There are three main size categories of lumber: Boards: 1 to 1 1/2� thick, 2� and wider Dimension lumber: 2 to 4� thick 2� and wider Timbers: 5� and thicker, 5� and wider Note 1: Thickness is the smaller cross sectional dimension and width is the larger dimension. Note 2: Dressed dimensions (S4S, Surfaced four Sides) are less than nominal dimensions (1.5�x3.5� for a 2x4). For stress calculations, dressed dimensions are used.

69. Dimension Lumber Joists and Planks Joists: 2-4 in thick and at least 6 in wide (graded based on bending strength on narrow edge) Planks: 2-4 in thick and at least 6 in wide (graded based on bending strength on wider dimension) Light Framing and Decking Light Framing: 2-4 in thick and 2-4 in wide (studs, joists and rafters) Decking: 2-4 in thick and 4 in or wider (used on their wider dimension)

70. Timbers Beams and Stringers: at least 4�thick and at least 2� wider than they are thick; installed horizontally and ranked based on bending stress when loaded on the narrower dimension Posts and Timbers: have a width that is no more then 2� greater than thickness (square or nearly square); installed vertically and ranked based on compression parallel to the grain

71. Design Values 71 An important part of wood design is being able to determine design values for the following mechanical properties: Bending stress, Fb Tension stress parallel to grain, Ft Shear stress, Fv Compressive stress parallel to grain, Fc Compressive stress perpendic. to grain, Fc? Modulus of Elasticity, E

72. Wet Service Factor (CM) Cont. 72 The tabulated values for sawn lumber apply to members with EMC of 19% or less. If MC in service will exceed 19% for an extended period of time, the tabulated values are to be multiplied by CM (CM values are less than one and are given at the beginning of Table 4A).

73. Cr= Repetitive Member Factor 73 A 15% increase in the tabulated Fb for repetitive-member systems is recognized in the NDS. A repetitive-member system is defined as one that has: 1. Three or more parallel members of dimension lumber 2. Members spaced not more than 24 in. o.c. 3. Members connected together by a load-distributing element such as roof, floor, or wall sheathing.

74. Cr= Repetitive Member Factor 74 If one member should become overloaded, parallel members come into play.

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