What we are understanding Grade 40 or grade 60?

The strength of concrete depends on its grade

or the ratio of cement to sand or gravel when mixed with water.

Grade ratings such as C15, C20, C25 and C30 indicate the relative compression resistance of a concrete mixThe number in the rating indicates how many amount of force the concrete can withstand.

 Steel grade40 &60 means the tensile strength of steel is40 ksi and60 ksi respectively.

Grade40 or grade60 indicate to yield strength of steel and for more information

Grade60 rebar offers a minimum yield strength of60,000 pounds per square inch, or420 megapascals on the metric grading scale. It also features a continuous line system, with one line running along the length of the bar which is offset a minimum of five spaces from the center. These characteristics make grade60 rebar particularly well-suited for medium- to heavy-duty concrete reinforcement applications.

Rebar with a grade40 designation offers a minimum yield strength of40,000 pounds per square inch and conforms to ASTM A-615 performance standards. Its metric counterpart is grade280 rebar, with an equivalent minimum yield strength of280 megapascals. This makes grade40 rebar an excellent choice for light- to medium-duty concrete reinforcing applications.

Concrete mix design – M60 grade of concrete provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.

A. Design Stipulation:Charastaristic comprehensive Strength @28 days =60 N/mm2Maximum size of aggregate =20 mmDegree of workability = CollapsibleDegree of quality control = GoodType of exposure = SevereMinimum cement content as per is456-2000

B. Test data for concrete ingredientsSpecific gravity of cement =3.15Specific gravity of fly ash =2.24Specific gravity of microsilica =2.21Setting time of cement initial =120 min, final =185 minCement compressive strength =45.21 N/mm2 @3 days54.82 N/mm2 @7 days69.32 N/mm2 @28 daysSpecific gravity of coarse aggregates (ca) and fine aggregates (fa)20 mm2.72910 mm2.747R/sand2.751C/sand2.697

Water absorption20 mm1.540,10mm1.780, R/sand3.780, C/sand4.490

Characterstic strength @28 days60 N/mm2Target mean strength : Depend upon degree of quality control “good” and considering (std. Dev.As5 N/mm2)

Characteristic strength given by the relation60 +(1.65 *5 ) =68.25 N/mm2

C. Quantities of ingredients ( by absolute volume Method )Actual cement used =450 kg/cumActual fly ash used =80 kg/cumActual microsilica used =40 kg/cumW/C fixed =0.24Absolute volume of cement =0.143Absolute volume of air =0.02Absolute vol of water. =0.137Absolute vol of fly ash. =0.036Absolute vol of microsilica =0.018

Total volume of CA and FA used =1.00-(0.143+0.036+0.018+0.02 +0.137)=0.619 Cum

D. Aggregate percent used.20 Mm =31,10 mm =25, r/sand =34, c/sand =10

(2.729*0.31) + (2.747*0.25) +(2.751*0.34 )+(2.697*0.10) *0.619*1000546+444+604+174=1768Aggt: cement =3.10 :1

Mix proportion =0.24:1:1.06:0.30:0.78:0.96

E. Abstract:20 mm546 kg/cum10 mm444 kg/cumr/sand604 kg /cumc/sand174 kg/cumwater137 kg/cum

Admixture1.80 % By wt of (C+F+MS) chemsonite SP450XL-B

Cube Compressive Strength (N/mm2)3 days =40.987 Days =57.7128 Days =70.96

Note: Mix design is same for crane bucket and pump concrete only admixture dosage will fine tuned by0.10%.We are thankful to Deshmukh D S for submitting this ver

what is the concerete strength 4 ksi

الجواب الصحيح هو إجابة المهندس  Sajid Mahmood

Steel grade40 &60 means the tensile strength of steel is40 ksi and60 ksi respectively

The grade of comcrete is one of the important properties of concrete which indeed unanimously by designer mean the strengh of concrete at28 days so as per your iinquiry means strength of concrete40 or60 N/mm2 

If you are considering concrete strength , grade40 or60 means the  crushing strength of mature concrete in28 days is equal to or exceeds40 N/mm2 or ...

Grades in Cement concretes are designed as per site requirements or usages.

Grade60 means the strength of cocrete after28 days should exceed60 MPa and for calculation of quantities the ratio of Water : Cement : FA : CA will be0.29 :1 :1.22 :2.22

Grade40 means the strength of cocrete after28 days should exceed40 MPa and for calculation of quantities the ratio of Water : Cement : FA : CA :  will be0.4:1 :1.75 :2.95