Project on Concrete Mix Design for various grades of Concrete

I)Stipulation for proportioning,

• Grade designation: M35
• Type and grade of cement : OPC 43 grade of cement conforming to IS8112
• Maximum nominal size of aggregate : 20mm
• Exposure condition: Severe conforming to table 3 IS456:2000
• Minimum cement content: 320kg/m^3 for RCC conforming to table 5 IS456:2000
• Method of placing: Pumpable
• Workability in terms of slump: 100mm conforming to clauseI 7.1 of IS456:2000
• Type of aggregate: Crushed angular aggregate
• Type of chemical admixture: Super plastizier conforming to IS9103
• Percentage of chemical admixture:2%
• Type of mineral admixture: Fly ash conforming to IS3812(part I)
• Maximum water cement ratio: 0.45 conforming to table 5 of IS456:2000
• Maximum cement content: 450kg/m^3 conforming to clauseI 8.2.4.2 of IS456:2000
• Degree of supervision: Good

II)Test data for materials,

• Cement used:OPC(Ordinary Portland Cement) 43 grade of cement conforming to IS8112
• Specific gravity of cement:3.15
• Type of chemical aggregate:Super plasticizer conforming to IS9103
• Type of Mineral aggregate:Fly ash conforming to IS3812(part I)
• Specific gravity of coarse aggregate:2.6
• Specific gravity of fine aggregate:2.6
• Water absorption of coarse aggregate:0.5%
• Water absorption of fine aggregate:1%
• Sieve analysis of coarse aggregate:Conforming to table 2 of IS383:1970
• Sieve analysis of fine aggregate:Conforming zone II to table 4 of IS383:1970

III)Target mean strength(f'ck),

                          f'ck=fck+1.65s (or) f'ck=fck+x

      Where,

                f'ck=target strength of concrete attain 28days

                fck =Compressive strength(35N/mm^2) of concrete attain 28days

                s    =Standard deviation(5N/mm^2) conforming to table 2 of IS10262:2019

                x    =6.5

                            f'ck=35+1.65*5=43.25N/mm^2 (or)f'ck=35+6.5=41.5N/mm^2

      Therefore,the estimated target strength of concrete(f'ck)=43.25N/mm^2

IV)Water cement ratio,

       From table 5 of IS456:2000

                            Maximum water cement ratio =0.45

       From the graph page no.4 of IS10262:2019

                            Maximum water cement ratio =0.40

       Take the least value,thus the estimated water cement ratio =0.40

V)Water content,

        From table 4 of IS10262:2019

                            Water content =186kg(for 50mm slump value)

• Aggregate type correction

                      As the given aggregate is crushed angular type,thereby reduce the water content by 0

                              Water content =186kg

• Slump correction

                      We have slump value =100mm

                               Water content =197kg

• Admixture correction

                       Since we use super platicizer ,reduce water content by 30%

                               Water content =138litre

VI)Cement content,

        Cement content =Water content/Water cement ratio

                                =138/0.40

         Cementitious material(cement+fly ash) content =345kg/m^3

         Minimum cement content(320kg/m^3) < cement content obtained(345kg/m^3)

                                 Hence ok.

         Here fly ash is 30% and cement is 70%

         Adding 10% to the cementitious materal content

         Thereby the cementitious material content =380kg/m^3

         Thus 30% fly ash in cementitious material content =114kg/m^3

         Total quantity of cement =266kg/m^3

         Saving cement using fly ash =79kg/m^3

         Water cement ratio =0.36

VII)Aggregate proportion between coarse aggregate and fine aggregate,

          From table 5 of IS10262:2019

                   The volume of coarse aggregate coresponding to the aggregate size and fine aggregate(zone II) of water cement ratio of 0.5=0.62

          In present we have water cement ratio =0.36

          Change in water cement ratio =0.14

          Factor of change =2.8

          Volume of coarse aggregate =0.648m^3

           For pumpable concrete reduce 10% of volume of coarse aggregate

           The estimated volume of coarse aggregate =0.5832m^3

           The estimated volume of fine aggregate =0.4168m^3

VIII)Mix calculation

• Volume of concrete: 1m^3
• Volume of cement: Mass of cement/specific gravity of cement*1/1000=0.084m^3
• Volume of water: Mass of water/specific gravity of water*1/1000=0.138m^3
• Volume of chemical admixture: Mass of chemical admixture/specific gravity of chemical admixture*1/1000=0.0046m^3
• Volume of fly ash: Mass of fly ash/specific gravity of fly ash*1/1000=0.051m^3
• Volume of all agregates(coarse and fine): volume of concrete-(Volume of cement+volume of water+volume of chemical admixture+volume of fly ash)=0.7224m^3
• Mass of coarse aggregate: volume of all agregate*volume of coarse aggregate*specific gravity of coarse aggregate*1000= 1095kg/m^3
• Mass of fine aggregate: volume of all agregates*volume of fine aggregate*specific gravity of fine aggregate*1000= 783kg/m^3

IX)Mix proportion for trial 1

• Cement:266kg/m^3
• Water:138litre
• Fine aggregate:783kg/m^3
• Coarse aggregate:1095kg/m^3
• Water cement ratio:0.36
• Chemical admixture:5kg/m^3
• Fly ash:114kg/m^3

CEMENT     :    FINE AGGREGATE    :     COARSE AGGREGATE

1               :    2.94                       :     4.11

X)Site correction,

• Coarse aggregate(dry mass): Mass of coarse aggregate/1+water absorption=1090kg/m^3
• Fine aggregate(dry mass): Mass of fine aggregate/1+water absorption=775kg/m^3

                                       Water content=138+5+8=151kg/m^3 

2.M50 design mix

I)Stipulation for proportioning,

• Grade designation: M50
• Type and grade of cement : OPC 43 grade of cement conforming to IS8112
• Maximum nominal size of aggregate : 20mm
• Exposure condition: severe conforming to table 3 IS456:2000
• Minimum cement content: 320kg/m^3 for RCC conforming to table 5 IS456:2000
• Method of placing: Pumpable
• Workability in terms of slump: 100mm conforming to clause 7.1 of IS456:2000
• Type of aggregate: Crushed angular aggregate
• Type of chemical admixture: Super plastizier conforming to IS9103
• Percentage of chemical admixture:2% of cement content
• Maximum water cement ratio: 0.45 conforming to table 5 of IS456:2000
• Maximum cement content: 450kg/m^3 conforming to clause 8.2.4.2 of IS456:2000
• Degree of supervision: Good

II)Test data for materials,

• Cement used:OPC(Ordinary Portland Cement) 43 grade of cement conforming to IS8112
• Specific gravity of cement:3.15
• Type of chemical aggregate:Super plasticizer conforming to IS9103
• Specific gravity of coarse aggregate:2.74
• Specific gravity of fine aggregate:2.74
• Water absorption of coarse aggregate:0.5%
• Water absorption of fine aggregate:1%
• Sieve analysis of coarse aggregate:Conforming to table 2 of IS383:1970
• Sieve analysis of fine aggregate:Conforming zone I to table 4 of IS383:1970

III)Target mean strength(f'ck),

                          f'ck=fck+1.65s (or) f'ck=fck+x

      Where,

                f'ck=target strength of concrete attain 28days

                fck =Compressive strength(50N/mm^2) of concrete attain 28days

                s    =Standard deviation(5N/mm^2) conforming to table 2 of IS10262:2019

                x    =6.5

                            f'ck=50+1.65*5=58.25N/mm^2 (or)f'ck=50+6.5=56.5N/mm^2

      Therefore,the estimated target strength of concrete(f'ck)=58.25N/mm^2

IV)Water cement ratio,

       From table 5 of IS456:2000

                            Maximum water cement ratio =0.45

       From the graph page no.4 of IS10262:2019

                            Maximum water cement ratio =0.33

       Take the least value,thus the estimated water cement ratio =0.33

V)Water content,

        From table 4 of IS10262:2019

                            Water content =186kg(for 50mm slump value)

• Aggregate type correction

                      As the given aggregate is crushed angular type,thereby reduce the water content by 0

                              Water content =186kg

• Slump correction

                      We have slump value =100mm

                               Water content =197kg

• Admixture correction

                       Since we use super platicizer ,reduce water content by 30%

                               Water content =138litre

VI)Cement content,

        Cement content =Water content/Water cement ratio

                                =138/0.33

         Cement content =418kg/m^3

         Minimum cement content(320kg/m^3) < cement content obtained(418kg/m^3)

                                 Hence ok.

VII)Aggregate proportion between coarse aggregate and fine aggregate,

          From table 5 of IS10262:2019

                   The volume of coarse aggregate coresponding to the aggregate size and fine aggregate(zone I) of water cement ratio of 0.5=0.60

          In present we have water cement ratio =0.33

          Change in water cement ratio =0.17

          Factor of change =3.4

          Volume of coarse aggregate =0.634m^3

           For pumpable concrete reduce 10% of volume of coarse aggregate

           The estimated volume of coarse aggregate =0.5706m^3

           The estimated volume of fine aggregate =0.4294m^3

VIII)Mix calculation

• Volume of concrete: 1m^3
• Volume of cement: Mass of cement/specific gravity of cement*1/1000=0.133m^3
• Volume of water: Mass of water/specific gravity of water*1/1000=0.138m^3
• Volume of chemical admixture: Mass of chemical admixture/specific gravity of chemical admixture*1/1000=0.0069m^3
• Volume of all agregates(coarse and fine): volume of concrete-(Volume of cement+volume of water+volume of chemical admixture+volume of fly ash)=0.7221m^3
• Mass of coarse aggregate: volume of all agregate*volume of coarse aggregate*specific gravity of coarse aggregate*1000= 1129kg/m^3
• Mass of fine aggregate: volume of all agregates*volume of fine aggregate*specific gravity of fine aggregate*1000= 850kg/m^3

IX)Mix proportion for trial 1

• Cement:418kg/m^3
• Water: 138litre
• Fine aggregate: 850kg/m^3
• Coarse aggregate: 1129kg/m^3
• Water cement ratio: 0.33
• Chemical admixture: 8kg/m^3

CEMENT     :    FINE AGGREGATE    :     COARSE AGGREGATE

1               :    2.03                       :    2.7

 X)Site correction

• Coarse aggregate(dry mass):Mass of coarse aggregate/1+water absorption=1123kg/m^3= 6kg/m^3
• Fine aggregate(dry mass):Mass of fine aggregate/1+water absorption=842kg/m^3= 8kg/m^3

                                                          Water content=138+6+8=152litre