G4S Interview Questions and Answers

To calculate material of M20 grade concrete, we need to know the ratio of cement, sand, and aggregate.

• M20 grade concrete has a mix proportion of 1:1.5:3 of cement, sand, and aggregate respectively.

• To calculate the quantity of each material, we need to know the volume of concrete required.

• Assuming the volume of concrete required is 1 cubic meter, the quantity of cement required would be 0.28 cubic meters.

• The quantity of sand required would be 0.42 cubic meters and the quantity...read more

Cement finesse test measures the particle size of cement. Initial and final setting time tests measure the time taken for cement to set.

• For cement finesse test, a sample of cement is sieved through a standard sieve and the residue is weighed.

• The residue is then sieved through a finer sieve and the weight of the residue is again measured.

• The difference between the two weights gives the fineness of cement.

• For initial and final setting time tests, a sample of cement is mixed wit...read more

Nominal mix is a mix of fixed proportions of cement, sand and aggregate. Design mix is a mix of desired proportions of cement, sand and aggregate.

• Nominal mix is used for small construction works and where quality control is not a major concern.

• Design mix is used for large construction works and where quality control is a major concern.

• Nominal mix has fixed proportions of materials, usually 1:2:4 for M15 grade concrete.

• Design mix has desired proportions of materials based on t...read more

NDT stands for Non-Destructive Testing. It is a type of testing that does not damage the material being tested.

• NDT is used to detect defects or irregularities in materials without causing damage.

• It is commonly used in industries such as aerospace, construction, and manufacturing.

• Some common NDT methods include ultrasonic testing, radiography, and magnetic particle testing.

• NDT is important for ensuring the safety and reliability of structures and equipment.

• It can also be used ...read more

M20 is a mix designation for concrete, indicating the compressive strength of the concrete mix after 28 days.

• M20 refers to a mix of concrete with a compressive strength of 20 megapascals (MPa) after 28 days of curing.

• It is commonly used for residential construction projects such as foundations, slabs, and footings.

• The mix consists of 1 part cement, 1.5 parts sand, and 3 parts aggregate.

• The higher the M number, the stronger the concrete mix.

• M20 is suitable for moderate exposur...read more

My Mtech project work was on the analysis of soil-structure interaction using finite element method.

• I conducted a literature review on the topic to understand the existing research

• I developed a 3D finite element model of a building foundation and soil using software like ANSYS or Abaqus

• I analyzed the model to determine the stresses and deformations in the soil and structure

• I validated the results by comparing them with experimental data or analytical solutions

• I presented my f...read more