Mix Design of M40 Grade of Concrete with OPC Cement

1. Mix stipulation for ingredients of concrete

• • Grade of Concrete : M40

• • Type of Cement : OPC 53 grade confirming to IS 269

• • Maximum Nominal Size Aggregate : 20 mm

• • Minimum Cement content : 380Kg/cum

• • Maximum Water- Cement Ratio : 0.4

• • Workability : 150 ± 25 mm (slump)

• • Exposure Condition : Moderate

• • Method of Concrete Placing : Pumping/Bucket 

• • Degree of Supervision : Good

• • Type of Aggregate : Crushed angular Aggregate, Crushed Stone Sand

• • Chemical admixture type : Super plasticizers Confirming IS 9103:1999

2. Material Properties

• • Cement : Ultratech OPC 53 grade confirming to IS 269

• • Specific Gravity of cement : 3.15

• • Chemical Admixture : BASF Master Glenium Sky 8511

• • Specific Gravity of Admixture : 1.07

• • Specific Gravity

    • • Coarse aggregate

        • • 20mm : 2.65

        • • 12.5mm : 2.63

    • • Fine aggregate :      Crushed stone aggregate  : 2.59                                                        

    • • Water : 1 

• • Water Absorption 

    • • Coarse aggregate :                                                                              

        • • 20 mm  :  0.37%                                                         

        • • 12.5 mm   : 0.54%                                                                  

    • • Fine aggregate                                                                                                                                      

        • • Crushed Stone Aggregate :  2.35%                                                                   

• • Free Surface Moisture                                                                        

    Coarse aggregate :  Nil                                                                                                          Fine aggregate  : Nil     

• • Sieve Analysis :

    • • Coarse aggregate :

        IS Seive Sizes	% Passing		IS Requirement as per IS 383 Table 2				Ratio		Confirming to IS 383 table 2
        			Single Sized		Graded		40%	60%
        	20 mm	12.5 mm	20 mm	12.5 mm			20 mm	12.5 mm	Combined 100%
        20	95.01	100	85-100	100	100		38.00	60	98.00
        12.5	0	99.15	–	85-100	90-100		0.00	59.49	59.49
        10	2.54	51.07	0-20	0 – 45	40 – 85		1.02	30.64	31.66
        4.75	0.88	0.42	0-5	0-10	0 – 10		0.35	0.25	0.60
        PAN	0	0	–	–	–		0	0	0

      • Fine Aggregate  : Confirming to grading Zone II of table 4 of IS 383      Note: – as per field trials for pumpable concrete fine aggregate should pass zone II; According to IS 383 clause No. 31.2.2 allows to use crushed stone sand as fine aggregate for concrete. According to IS 383-2016 for crushed stone sand, the permissible limit on 150 micron IS sieve is increased to 20%.

        IS Seive Sizes	% Passing		Ratio River Sand:Msand		A		Combined Passing
        			A	B	IS 383 Zone II
        	R Sand	M Sand	R Sand	M Sand
        4.75	0	100	0	100	90-100		100
        2.36	0	85.88	0	85.88	75-100		85.88
        1.18	0	58.95	0	58.95	55-90		58.95
        600	0	38.87	0	38.87	35-59		38.87
        300	0	21.47	0	21.47	8-30		21.47
        150	0	9.74	0	9.74	0-10		9.74

      • All in Aggregate :  

        IS Seive Sizes	22.8%	34.2%	43%	Specification			Combined Passing
        	20mm	12.5mm	c sand	min-max
        40	100	100	100	100-100			100.00%
        20	95.01	100	100	95-100			98.86%
        4.75	0.88	0.42	100	30-50			43.34%
        0.6	0	0	38.87	10-35			16.71%
        0.15	0	0	9.74	0-6			4.19%

        3. Stipulation of Target Mean Strength and Mix Proportioning as per MORTH

        Target Mean Strength for M-40 Grade =52Mpa                                                                                                                                                                                                

        4. Calculation for water/Cement Ratio (W/C) 

      • As per technical specification max Water/Cement + Binder=  0.4   

        5.Calculation for Water content

      • Ref Tab 2 , IS 10262 , Maximum water content per cum for  20mm Aggregate             =             186         litre for 50 mm slump                          186 + (0.09 * 186) (add 3% for every 25 mm increase) =203 lit        

      •   Based on trials with super plasticizers, water content reduced by 29%, hence the arrived water content   = 139.89                                                      Let us add water 140lit                                                                         

        6. Calculation for Cementious content            

         Water-Cementitious Ratio = 0.36                                                       Cementious content (Cement OPC 53 + GGBFS) = 389                         Say         Cementitious     = 390  ,

        Cement =390         kg/m3                                                  

        Based on experience and lab trials,     super plasticizer= 0.48 %                                                                                                  

        7.Calculation for arriving Aggregate content                                                          

      • Ref Tab 3 of IS 10262, for Sand Zone II ,  volume of coarse aggregate per unit vol of total aggregate for 0.5 water-cement ratio =   0.62     

      •     Adjust for W/c ratio: Add @ 0.01 for every decrease in 0.05 = 0.028 

      • Therefore, corrected proportion=  0.648 

      •    Adjust for pumpability, i.e. decrease by 10%    =   0.58 %                   

      •  Based on experience  Considering Volume of coarse aggregate=0.57                           

      • Therefore, Volume of Fine aggregate =0.43                                                       

        8.Mix volume Calculation per cubic meter                                      

      • a)Volume of concrete   =   1  m3 

      • b) Volume of cement   =   Mass of cement  specific gravity of cement × 1000 = 0.1238   m3         

      • c)Volume of water = Mass of water  x  specific gravity of water× 1000    =    0.140     m3  

      • d)Volume of admixture =  Mass of admixture  x specific gravity of admixture× 1000    =   0.00175  m3

      • e) Volume of all in aggregate =  [a-(b+c+d)]   =  0.73        m3    

        • f) Mass of coarse aggregate                                                                                                                               

                                                    1) 20 mm    =   e × volume of CA × sp. gravity × % of 20mm × 1000   
                                                                                                        =             0.73*0.57*2.65*0.5*1000                                                                            
                                                                                                        =             443.75   kg/m3                                                  
                                                                                                Say                   444  kg/m3                                                  
        
                                                  2) 12 mm  =   e× volume of CA × sp. gravity × % of 12mm × 1000                                                                               
                                                                                                        =             0.73*0.57*2.63*0.5*1000                                                                            
                                                                                                        =             660.60   kg/m3                                                  
                                                                                                Say              661   kg/m3                                                  

        • g) Mass of Fine aggregate =  e × volume of FA × sp. gravity × 1000                                                                               

                                                                            =      0.73*0.43*2.59*1000                                                                     
                                                                            =      817.95   kg/m3                                                  
                                                                   Say          818  kg/m3  

                                                        
        
        

        9.Mix Details   

                                                                                                                                                      
                         cement     =   390  kg                                                                                                                 
                        20mm        =    444  kg                                                         
                        12mm        =    661   kg                                                          
                        Crushed stone sand   =    818   kg                                                          
                        Chemical admixture   =    1.87  kg                                                          
                        Free Water       =    140 kg                                                          
                        Water-Cement Ratio   =     0.36                                                                       
                        Concrete density     =    2454  kg/m3