Bissoy.com
Doctors Medicines MCQs Q&A

What is the characteristic strength of M-15 concrete?

What is the characteristic strength of M-15 concrete? Correct Answer 15 N/mm<sup>2</sup>

The strength of a concrete mix is specified as its characteristic strength.

The characteristic strength of a concrete mix is defined as the compressive strength of 150 mm cube at 28 days expressed in N/mm2 below which not more than 5 per cent of the test results are expected to fall.

The different concrete mixes are graded, and each mix is identified by its grade designation. In the designation of the concrete, mix, a letter M is used to denote the mix and a number is specified, which is numerically equal to characteristic strength at 28 days.

∴ In the designation of a concrete mix, the letter 'M' and the number stands for Mix and characteristic compressive strength of 150 mm cube at 28 days.

∴ The M 15 grade of concrete means the concrete mix which attains 28 day strength (characteristics) as 15 MPa or 15 N/mm2.

Related Questions

The influence of shape of aggregate in strength and workability of concrete are given below in statements S1, S2, S3 and S4. Which of the statements are correct? S1: Rounded aggregate produces concrete with high workability and low strength. S2: Angular aggregate produces concrete with high workability and low strength. S3: Rounded aggregate produces concrete with low workability and high strength. S4: Angular aggregate produces concrete with low workability and high strength.
With regard to the characteristic strength of concrete, consider the following statement: “Test strength of samples means the average strength of X samples. The strength of a sample should not vary by more than ± Y% of the average strength. What will be the values of X and Y here?
Permeability in concrete is studied towards providing for, or guarding against, which of the following features? 1. The penetration by materials in solution may adversely affect the durability of concrete; moreover, aggressive liquids 'attack' the concrete. 2. In the case of reinforced concrete, ingress of moisture and air will result in corrosion of steel leading to an increase in the volume of steel, resulting in cracking and swilling of the concrete cover. 3. The moisture penetration depends on permeability and if the concrete can become saturated with water it is less vulnerable to frost action.
Consider the following statements: 1. If more water is added to concrete for increasing its workability, it results into concrete of low strength. 2. No slump is an indication of a good workable concrete. 3. Higher the slump of concrete, lower will be its workability. 4. Workability of concrete is affected by water content as well as water-cement ratio. Which of the above statements are correct?
Which of the following statements describe(s) limitation(s) of concrete technology? A. Availability of concrete ingredients easily. B. Due to low tensile strength, concrete is required to be reinforced to avoid cracks. C. Monolithic character gives better appearance D. The property of concrete possesses high compressive strength.
A steel column of ISHB 350 @72.4 kg/m is subjected to a factored axial compressive load of 2000 kN. The load is transferred to a concrete pedestal of grade M20 through square base plate. Consider the bearing strength of concrete as 0.45 fck, where fck is the characteristic strength of concrete. Using limit state method and neglecting the self-weight of base plate and steel column, the length of a side of the base plate to be provided is
Calculate ultimate moment and shear of effective span is 30m, live load is 9kn/m, dead load excluding self weight is 2kn/m, load factors for dead load is 1.4 for live load is 1.6 cube strength of concrete fcu is 50n/mm2 cube strength at transfer is fci is 35n/mm2, tensile strength of concrete Ec is 34kn/mm2 loss ratio ɳ is 0.85 and 8mm diameter high tensile strength fpu is 1500n/mm2 are available for use and the modulus of elasticity of high tensile wires is 200kn/mm2?
The following statements (S1, S2, S3) pertain to mass concreting. Which of the following statements are correct? S1: The materials preferred for mass concrete are: Portland cement with low heat of hydration, Pozzolanas, Aggregates (coarse and fine), Water, Admixture, Coolants. S2: Slump of mass concrete shall be the same or more than ordinary concrete work. S3: Concrete with a low water cement ratio, correctly consolidated and properly cured provides durability to mass concrete work.
Consider the following statements related to the advantages of concrete sleepers : 1. Concrete sleepers can generally be mass-produced using local resources. 2. Concrete sleepers are not suitable for better packing. 3. Concrete sleepers have a very long life span. 4. Concrete sleepers have no scrap value. Which of the above statements is/are correct?
Which of the following statements is/are true about the advantages of prestressed concrete structure? A. In the prestressed concrete structure, the deflection of beams is considerably reduced. B. Prestressing decreases cracks in concrete under all stages of loading. C. Prestressed concrete requires only 1/3 rd of the concrete required for R.C.C.