The compressive strength of M20 concrete at 28 days typically falls in the range of 20 to 25 megapascals (MPa), which is equivalent to 2900 to 3600 pounds per square inch (psi). M20 is a mix designation for concrete, where "M" stands for "mix" and the number 20 represents the characteristic compressive strength of the concrete mix in MPa.
Please note that the actual compressive strength of M20 concrete can vary depending on several factors, including the quality of materials used, the water-cement ratio, the curing conditions, and the testing procedures. To ensure the desired strength, it's essential to follow the recommended mix proportions and proper construction practices during the preparation, placing, and curing of the concrete. Additionally, testing of concrete samples is typically conducted in a laboratory environment to determine the 28-day compressive strength accurately.
The compressive strength of concrete is typically measured at different ages, including 7 days, 28 days, and sometimes even longer durations. The strength of concrete is influenced by various factors such as the mix design, curing conditions, quality of materials, and testing procedures.
In the case of M45 concrete, which refers to concrete with a characteristic compressive strength of 45 megapascals (MPa), the expected compressive strength at 7 days can vary. However, it is common to expect approximately 60-70% of the 28-day strength at 7 days.
Therefore, for M45 concrete, the estimated compressive strength at 7 days would be around 27 to 31.5 MPa. However, it's important to note that these values are approximate and can vary depending on the specific mix design and curing conditions used in a particular project.
To obtain accurate information about the compressive strength of concrete at a specific age, it is recommended to consult the mix design or conduct laboratory testing according to relevant standards and procedures.
For M25 grade concrete the seven days crushing for site condition shall be not less than 67 % of M25, i.e not less than 16.75 N/mm2 But for target strength of M25 for mix design taken i.e for M25 it is 32 and the 7 days strength shall not be less than 22 N/mm2
ANS: The 7-day strength of concrete should not be less than 2/3 of the 28-day strength
The Compressive strength of M 20 concrete at 28 days is 20 MPa target mean strength is fck + kS.
k= risk factor( 95% of test results is passed,i.e, 1 in 20)
s= standard deviation
Wate is the compressive strength of m10,m15,
The compressive strength of concrete M30 in 7 day is 20.1N/mm2
70 % of 45 N/mm2
20 mega-pascal of pressure
19.5 N/mm2
M20 refers to the grade of the concrete generally used in construction purpose. Here, M refers to mix & number 20 refers to the characteristic strength of concrete. the proportions of this grade is (1:1 1/2: 3). Along with this there are some more grades used in constructions i.e., M5, M7.5, M10, M15, M25, M30................. M80
The ratios of cement to sand to aggregate for the different grades of concrete are as follows. M10 has a ratio of 1:3:6. M15 has a ratio of 1:2:4. M20 has a ratio of 1:1.5:3. M25 has a ratio of 1:1:2, but M30 has no set ratio. It is a designed mixture to achieve the stress tolerance desired.
1:2:4
Mix ratio for M10 concrete is 1:3:6compressive strength is 10N/mm2 @ 28 days.1 part of cement, 3 part of sand, 6 parts of coarse aggregate.
It is the bearing capacity in N/mm2 when tested on 21 day on a hydraulic testing m/c When we tested this grade concrete cubes on 28th day the compressive strength value have to come 35 N/mm2.
Ration used in M10 concrete is 1:3:6 1 Cement, 3 Sand & 6 Aggregate
1:4:8
1:4:8
4.4 bags
4.50/bag cement, required for 1 cubic metre of concrete ( M10).
4.4 Bags
The mixes of grades M5 M10, M15, M20 and M25 correspond approximately to the mix proportions (1:4:8), (1:3:6), (1:2:4), (1:1.5:3) and (1:1:2) respectively.
M20 refers to the grade of the concrete generally used in construction purpose. Here, M refers to mix & number 20 refers to the characteristic strength of concrete. the proportions of this grade is (1:1 1/2: 3). Along with this there are some more grades used in constructions i.e., M5, M7.5, M10, M15, M25, M30................. M80
from M30 onwards the mixes are designed. they dont have a const ration as in the case of mixes like M10, M15....,M25