UltraTech Cement QC Chemist Interview Questions and Answers

Different types of sands used in concrete have specific limits and are governed by IS codes for various works and materials.

• Different types of sands used in concrete include river sand, crushed sand, and manufactured sand.

• IS codes such as IS 383 specify the limits for different types of sands used in concrete.

• Mix designs for concrete involve determining the proportions of cement, sand, aggregate, and water to achieve the desired strength and durability.

• For example, IS 456 pro...read more

Free lime testing involves titration method to determine the amount of lime and MgO present in a sample.

• Free lime testing involves adding a known amount of acid to the sample to react with the lime and MgO present.

• The excess acid is then titrated with a base to determine the amount of acid that reacted with the lime and MgO.

• The difference in volume of acid and base used in the titration gives the amount of lime and MgO present in the sample.

NC stands for normal consistency and setting time refers to the time taken for a material to harden.

• NC is the water content at which a cement paste has standard consistency for testing.

• Setting time is the time taken for a material to change from a liquid to a solid state.

• Setting time can be influenced by factors like temperature, humidity, and the composition of the material.

• For example, in cement testing, NC is determined by measuring the penetration of a standard needle int...read more

Slump is a measure of consistency of concrete. IS codes are Indian Standards codes used for construction materials.

• Slump is the vertical displacement of concrete when a cone is removed.

• IS codes provide guidelines for quality and safety of construction materials.

• IS 456 is the code for plain and reinforced concrete design.

• IS 10262 is the code for concrete mix design.

• IS 1199 is the code for methods of sampling and analysis of concrete.

The size of the packing bag can affect the Blaine of cement, as smaller bags may have higher Blaine values due to increased surface area.

• Smaller packing bag sizes can lead to higher Blaine values in cement

• Larger packing bag sizes may result in lower Blaine values

• The surface area of the cement particles can impact the Blaine value

• Example: Using 50kg bags vs 25kg bags for cement packaging

Blaine of cement is a measure of the fineness of cement particles.

• Blaine is measured in terms of specific surface area (cm²/g)

• Higher Blaine values indicate finer cement particles

• Blaine test is commonly used in cement quality control