s2 concrete materials.pptx - read-only

URP S-09 TrainingModule S2

Concrete MaterialsDate: 31 March 2021

Raquib Ahsan, PhDProfessor, Department of Civil Engineering, BUET

Relevant Chapters

Part 5: Chapter 2

Part 6: Chapter 5

Part 6: Chapter 6

Part 6: Chapter 8

Part 7: Chapter 2

S. K. Ghosh Associates LLC International Code Council (ICC)

www.skghoshassociates.com 1

Part 5 Chapter 2

Materials used for the construction of buildings shall conform to standard specifications listed in this Part of the Code.

The provisions of this Part are not intended to prevent the use of any new and alternative materials. Any such material may be approved provided it is shown to be satisfactory for the purpose intended.

Approval in writing shall be obtained by the owner or his agent before any new, alternative or equivalent materials are used. The Building Official shall base such approval on the principle set forth above.

The provisions of this Part do not preclude the use of used or reclaimed materials provided such materials meet the applicable requirements as for new materials for their intended use.

Aggregates

BDS 243: 1963, Coarse and Fine Aggregates from Natural Sources for Concrete; ASTM C33/C33M Concrete Aggregates; ASTM C330/C330M Lightweight Aggregates for Structural Concrete; ASTM C637 Aggregates for Radiation-Shielding Concrete; ASTM C332 Lightweight Aggregate for Insulating Concrete; IS: 9142 Artificial lightweight aggregates for concrete masonry units.

Nominal sizeNominal maximum size of coarse aggregate shall not be larger than:(a) One-fifth of the narrowest dimension between sides of forms; or(b) One-third the depth of slabs; or(c) Three fourths the minimum clear spacing between individual reinforcing bars or wires, bundles of bars, or pre-stressing tendons or ducts.

Coarse aggregate made from Grade A brick as specified in BDS 208 "Specification for Common Building Clay Bricks" may be used in different types slab and non-structural elements, except in applications where the ambient environmental conditions may impair the performance of concrete made of such aggregates.



ASTM C33

•The fine aggregate shall have not more than 45 % passing any sieve and retained on the next consecutive sieve and its fineness modulus shall be not less than 2.3 nor more than 3.1.



Cement

Cement shall conform to the following standards: BDS EN 197-1:2003 Cement Part-1 Composition, specifications and conformity criteria for common cements, BDS 612 Sulphate resisting Portland cement-type A, ASTM C150/C150M Standard Specification for Portland Cement, BDS 232 Portland cement, ASTM C595/C595M Blended Hydraulic Cements, and to other such cements listed in ACI 318.

BDS EN 197-1:2010 (Cement Type)



BDS EN 197-1:2010 (Composition)

Cement Constituents

Portland cement clinker (K): Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates (3CaO SiO2 and 2CaO SiO2).Granulated blast furnace slag (S): Granulated blast furnace slag is made by rapid cooling of a slag melt of suitable composition, as obtained by smelting iron ore in a blast furnace. Granulated blast furnace slag shall consist of at least two-thirds by mass of the sum of calcium oxide (CaO), magnesium oxide (MgO) and silicon dioxide (SiO2).Pozzolanic materials (P, Q): Pozzolanic materials are natural substances of siliceous or silico-aluminous composition or a combination thereof. Pozzolanic materials do not harden in themselves when mixed with water but, when finely ground and in the presence of water, they react at normal ambient temperature with dissolved calcium hydroxide (Ca(OH)2) to form strength-developing calcium silicate and calcium aluminate compounds.



Cement Constituents

Natural pozzolana (P): Natural pozzolanas are usually materials of volcanic origin or sedimentary rocks with suitable chemical and mineralogical composition.

Natural calcined pozzolana (Q): Natural calcined pozzolanas are materials of volcanic origin, clays, shales or sedimentary rocks, activated by thermal treatment.

Fly ashes (V, W): Fly ash is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases from furnaces fired with pulverised coal.

Siliceous fly ash (V): Siliceous fly ash is a fine powder of mostly spherical particles having pozzolanic properties. It consists essentially of reactive silicon dioxide (SiO2) and aluminium oxide (Al2O3).

Calcareous fly ash is a fine powder, having hydraulic and/or pozzolanic properties. It consists essentially of reactive calcium oxide (CaO), reactive silicon dioxide (SiO2) and aluminium oxide (Al2O3).

Cement Constituents

Burnt shale (T): Burnt shale, specifically burnt oil shale, is produced in a special kiln at temperatures of approximately 800 °C.

Limestone (L, LL): The calcium carbonate (CaCO3) content calculated from the calcium oxide content shall be at least 75 % by mass. The total organic carbon (TOC) content -

1) LL: shall not exceed 0,20 % by mass;

2) L: shall not exceed 0,50 % by mass.

Silica fume (D): Silica fume originates from the reduction of high purity quartz with coal in electric arc furnaces in the production of silicon and ferrosilicon alloys and consists of very fine spherical particles containing at least 85 % by mass of amorphous silicon dioxide.



BDS EN 197-1:2010 (Strength Class)

ASTM C150

1.1 This specification covers ten types of portland cement, as follows (see Note 2):1.1.1 Type I—For use when the special properties specified for any other type are not required.1.1.2 Type IA—Air-entraining cement for the same uses as Type I, where air-entrainment is desired.1.1.3 Type II—For general use, more especially when moderate sulfate resistance is desired.1.1.4 Type IIA—Air-entraining cement for the same uses as Type II, where air-entrainment is desired.1.1.5 Type II(MH)—For general use, more especially when moderate heat of hydration and moderate sulfate resistance are desired.1.1.6 Type II(MH)A—Air-entraining cement for the same uses as Type II(MH), where air-entrainment is desired.1.1.7 Type III—For use when high early strength is desired.1.1.8 Type IIIA—Air-entraining cement for the same use as Type III, where air-entrainment is desired.1.1.9 Type IV—For use when a low heat of hydration is desired.1.1.10 Type V—For use when high sulfate resistance is desired



ASTM C150 (Con’d)

ASTM C150 (Cont’d)



ASTM C595

1.1 This specification pertains to five classes of blended hydraulic cements for both general and special applications, using slag or pozzolan, or both, with portland cement or portland cement clinker or slag with lime.4.1.1.1 Type IS—Portland blast-furnace slag cement. The slag constituent is between 25 and 70%.4.1.1.2 Type IP—Portland-pozzolan cement. The pozzolan constituent is between 15 and 40% 4.1.1.3 Type P—Portland-pozzolan cement for use when higher strengths at early ages are not required4.1.1.4 Type I(PM)—Pozzolan—modified portland cement. The pozzolan constituent is less than 15%.4.1.1.5 Type I(SM)—Slag-modified portland cement. The slag constituent is less than 25%.4.1.2 Type S—Slag cement for use in combination with portland cement in making concrete and in combination with hydrated lime in making masonry mortar. The slag constituent is at least70%.


6.5 Blast-Furnace Slag—Blast-Furnace slag shall be the nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace.6.13 Pozzolan—Pozzolan shall be a siliceous or siliceous and aluminous material, which in itself possesses little or no cementitious value but which will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties.




Water

Water used in mixing concrete shall be clean and free from injurious amounts of oils, alkalies salts, organic materials or other substances that may be deleterious to concrete or reinforcement.

Nonpotable water shall not be used in concrete unless the following are satisfied:

(a)Selection of concrete proportions shall be based on concrete mixes using water from such source.(b)Mortar test cubes made with nonpotable mixing water shall have 7 days and 28 days strengths equal to at least 90 percent of strengths of similar specimens made with potable water.



Metal Reinforcement

Modulus of elasticity E_s for reinforcement shall be taken as 200 kN/mm2.

Deformed Reinforcement: Deformed reinforcing bars shall conform to the following Standards; BDS ISO 6935-2:2010, Steel for the reinforcement of concrete - Part-2: Ribbed bars; Reinforcement conforming to the ASTM, Standards: A615/A615M Deformed and Plain Billet-Steel Bars; A616M, Rail-Steel Deformed and Plain Bars; A617M Axle-Steel Deformed and Plain Bars; A706M Low-Alloy Steel Deformed Bars; A767M Zinc Coated (Galvanized) Steel Bars; and A775M Epoxy-Coated Reinforcing Steel.

Deformed reinforcing bars with a specified yield strength fy exceeding 410 MPa may be used, provided fy shall be the stress corresponding to a strain of 0.35 percent and the bars otherwise conform to ASTM standards noted above.

Welded deformed steel wire fabric conforming to ASTM A497/A497M may be used; for a wire with specified yield strength fy exceeding 410 MPa, fy shall be the stress corresponding to a strain of 0.35 percent. Welded intersections shall not be spaced farther apart than 400 mm in direction of calculated stress, except for wire fabric used as stirrups.

Bar Sizes according to BDS ISO 6935-2-2016Figure caption



Stress-Strain Property of Mild-Steel

Rm

ReH

Agt A

BDS ISO 6935-2-2016Figure caption



Bar Sizes according to ASTM A615

Tensile Strength Requirements according to ASTM A615



Design Strength

Design strength of reinforcement represented by the values of fy and fyt used in design calculations shall not exceed 550 MPa, and for transverse reinforcement in Sections 6.3.9.3 and 8.3. fy or fytmay exceed 420 MPa, only if the ratio of the actual tensile strength to the actual yield strength is not less than 1.20, and the elongation percentage is not less than 16.

Admixtures

5.2.4.4 Air entraining admixtures, if used in concrete, shall conform to "Specification for Air entraining Admixtures for Concrete" (ASTM C260).5.2.4.5 Water reducing admixtures, retarding admixtures, accelerating admixtures, water reducing and retarding admixtures, and water reducing and accelerating admixtures, if used in concrete, shall conform to "Standard Specification for Chemical Admixtures for Concrete" (ASTM C494/C494M) or "Standard Specification for Chemical Admixtures for use in Producing Flowing Concrete" (ASTM C1017/C1017M).



ASTM C494• Type A Water-reducing admixtures;

• Type B Retarding admixtures;

• Type C Accelerating admixtures;

• Type D Water-reducing and retarding admixture;

• Type E Water-reducing and accelerating admixtures;

• Type F Water-reducing, high-range, admixtures;

• Type G Water-reducing, high-range, and retarding admixtures; and

• Type S Specific performance admixtures.

Suggested Workability

Placing Conditions Degree ofWorkability

Values of Workability

Concreting of thin sections with vibration Very low 20 10 seconds Vee Bee time, or0.75 0.80 compacting factor

Concreting of lightly reinforced sections with vibration Low 10 5 seconds Vee Bee time, or0.80 0.85 compacting factor

Concreting of lightly reinforced sections without vibrationor heavily reinforced section with vibration

Medium 5 2 seconds Vee Bee time, or0.85 0.92 compacting factor, or25 75 mm slump for 20 mmaggregate*

Concreting of heavily rein forced sections withoutvibration

High Above 0.92 compacting factor,or75 125 mm slump for 20 mmaggregate*

* Slump test shall be performed as per ASTM C143. For smaller aggregates the values will be lower.



Requirements for Normal Weight Aggregate Concrete Exposed to Sulphate Containing Solutions

SulphateExposure Water Soluble Sulphate (SO4) in

Soil, percent by Weight

Sulphate(SO4)

in Water,(ppm)

Cement Type1MaximumWaterCement Ratio, by

Weight

Negligible 0.00 0.10 0 – 150

Moderate2 0.10 0.20 150 1500 Other than CEM I and Btype

0.50

Severe 0.20 2.00 1500 10,000 Other than CEM I and Btype

0.45

Verysevere

Over 2.00 Over 10,000 Other than CEM I and Btype

0.45

Notes: Pozzolan that has been determined by test or service record to improve sulphate resistance when used in concrete containingType V cement.1 For types of cement see BDS EN 197 1:2003 or ASTM C150 and C5952 Sea water

Maximum Chloride-ion Content for Corrosion Protection

Type of Member MaximumWater Soluble Chloride Ion(Cl ) in Concrete,

Percent by Weight of Cement

Prestressed concrete 0.06Reinforced concrete exposed to chloride inservice 0.15

Reinforced concrete that will be dry orprotected from moisture in service 1.00

Other reinforced concrete construction 0.30



Minimum Concrete Strength

Minimum concrete strength for structural use of reinforced concrete shall be 20 N/mm2. However, for buildings up to 4 storey, the minimum concrete strength may be relaxed to 17 N/mm2.

Maximum Permissible Water-Cement Ratio

Specified CompressiveStrength*,

N/mm2

Absolute Water Cement Ratio by Weight

Concrete other than airentrained

Air entrainedconcrete

1720253035

0.660.600.500.40**

0.540.490.39****

* 28 day strength. With most materials, water cement ratios shown will provide average strengths greater than thatrequired in Sec 5.6.2.2.

** For strengths above 30 N/mm2 (25 N/mm2 for air entrained concrete) concrete proportions shall be established bymethods of Sec 5.6.2.



Curing

5.11.1 Concrete (other than high early strength) shall be maintained above 10oC and in a moist condition for at least the first 7 days after placement, except when cured in accordance with Sec 5.11.3.5.11.2 High early strength concrete shall be maintained above 10oC and in a moist condition for at least the first 3 days, except when cured in accordance with Sec 5.11.3.

Frequency of Testing

At least one set for • Once a day• 60 m3 concrete• 250 m2 surface area

At least 3 sets for a project

If total vol < 20 m3 no test required

One set means at least two 150 mm x 300 mm cylinders or three 100 mm x 200 mm cylinders

36



Acceptance of Test Results

For laboratory cured samples:• Average of 3 sets fc’• Average of each set fc’ – 3.5 N/mm2

For field cured samples: Procedure of curing shall be improved if,

• Average of each set 0.85 fc’ and• Average of each set fc’ – 3.5 N/mm2

37

Investigation of Low Strength Test Results

3 cores for each low strength set

Adequate if,

• Average of 3 cores 0.85fc’ and

• each core 0.75fc’

If adequacy remains in doubt then load test

38



Conduits and Pipes Embedded in Concrete

Conduits and pipes of aluminium shall not be embedded in structural concrete unless effectively coated or covered to prevent aluminium concrete reaction or electrolytic action between aluminium and steel.

Conduits and pipes, with their fittings, embedded within a column shall not displace more than 4 percent of the area of cross-section on which strength is calculated or which is required for fire protection.

They shall not be larger in outside dimension than one third (1/3) the overall thickness of slab, wall, or beam in which they are embedded.

They have nominal inside diameter not over 50 mm and are spaced not less than 3 diameters on centres.

They shall not impair significantly the strength of the construction.

No liquid, gas, or vapour, except water not exceeding 30oC nor 0.3 N/mm2 pressure, shall be placed in the pipes until the concrete has attained its design strength.

Concrete cover for pipes, conduits, and fittings shall be not less than 40 mm for concrete exposed to earth or weather, nor 20 mm for concrete not exposed to weather or in contact with ground.

Reinforcement with an area not less than 0.002 times the area of concrete section shall be provided normal to piping.

Concrete for Various Exposure Conditions



Concrete in special moment frames and special structural walls

Compressive strength of the concrete shall be not less than 21 N/mm2. Specified compressive strength of light-weight concrete, shall not exceed 35MPa unless demonstrated by experimental evidence.

Reinforcement in special moment frames and special structural walls

Deformed reinforcement resisting earthquake-induced flexural and axial force, or both, shall comply with ASTM A706 Grade 420. Alternatively only BDS ISO 6935-2 Grades 300, 350, 400 and 420 or ASTM A615 Grades 275 and 420 reinforcement shall be permitted if:

• The actual yield strength based on mill tests does not exceed fy by more than 125 N/mm2 (retests shall not exceed this value by more than an additional 20 N/mm2); and

• The ratio of the actual tensile strength to the actual yield strength is not less than 1.25.

• Minimum elongation in 200 mm shall be at least 14 percent for bar dia. 10 mm to 20 mm, at least 12 percent for bar dia. 22 mm through 36 mm, and at least 10 percent for bar dia. 40 mm to 60 mm.

The value of fyt used to compute the amount of confinement reinforcement shall not exceed 700 N/mm2.



ASTM A706

ACI 318-19

Starting with ACI 318-19, ASTM A706 Grades 80 and 100 reinforcement is permitted to resist moments, axial, and shear forces in special structural walls and all components of special structural walls, including coupling beams and wall piers. ASTM A706 Grade 80 reinforcement is also permitted in special moment frames. The use of Grade 100 reinforcement is not allowed in special moment frames because there is insufficient data to demonstrate satisfactory seismic performance.ASTM A615 Grade 80 and Grade 100 are not permitted in special seismic systems.



Welding

Reinforcement required by factored load combinations which include earthquake effect shall not be welded. In addition, welding shall not be permitted on stirrups, ties, inserts, or other similar elements to longitudinal reinforcement required by design.

Shotcrete

• Shotcrete shall be defined as mortar or concrete pneumatically projected at high velocity onto a surface.

• Coarse aggregate, if used, shall not exceed 20 mm in size.• The maximum size of reinforcement shall be 16 mm Ø bars

unless it can be demonstrated by preconstruction tests that adequate embedment of larger bars can be achieved.

• When required by the engineer a test panel shall be shot, cured, cored or sawn, examined and tested prior to commencement of the project.



Cement Storage

To be stored at the work site in a building or a shed which is dry, leak proof and moisture proof.Bags to be stacked on wooden planks maintaining a minimum clearance of 200 mm from the floor.Maximum height of the stack shall be 15 bags and the width not more than four bags or 3m.In stacks more than 8 bags high, the bags shall be arranged alternate length and crosswise.Cement shall be used in the order they are received; storage shall facilitate this requirement. Hooks shall not be used.Workers handling cement shall put on protective hand and face coverings.

Steel Storage

Reinforcement bars and structural steel sections shall be coated with cement wash before stacking.

Bars of different types, sizes and lengths and structural steel sections shall be stored separately to facilitate issues.

Ends of bars and sections of each type shall be painted with separate designated colors.



Questions?Thank you



s2 concrete materials.pptx - read-only

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