Dalmia Bharat Cement Technical Service Engineer Interview Questions and Answers

Tests on fresh concrete include slump test, air content test, and temperature test. Tests on hardened concrete include compressive strength test, flexural strength test, and durability test.

• Tests on fresh concrete: slump test, air content test, temperature test

• Tests on hardened concrete: compressive strength test, flexural strength test, durability test

Types of cement include Portland cement, white cement, rapid hardening cement, low heat cement, sulfate resisting cement, etc.

• Portland cement is the most common type used in construction

• White cement is used for architectural purposes

• Rapid hardening cement sets quickly

• Low heat cement generates less heat during hydration

• Sulfate resisting cement is used in areas with high sulfate content in soil or water

The main reasons for cracks development in slabs include shrinkage, settlement, overloading, and poor construction practices.

• Shrinkage of concrete during curing process

• Settlement of underlying soil

• Overloading beyond the design capacity

• Poor construction practices such as inadequate reinforcement or improper curing

• Temperature changes causing expansion and contraction

IS Codes for different types of cement

• IS 269: Ordinary Portland Cement

• IS 455: Portland Slag Cement

• IS 1489: Portland Pozzolana Cement

• IS 8041: Rapid Hardening Portland Cement

• IS 12330: Sulphate Resisting Portland Cement

The target strength of concrete is calculated using the characteristic compressive strength of concrete and the standard deviation.

• Calculate the characteristic compressive strength of concrete based on the mix design.

• Determine the standard deviation of the concrete mix.

• Use the formula: Target strength = Characteristic strength + (1.65 * Standard deviation)

• For example, if the characteristic strength is 30 MPa and the standard deviation is 4 MPa, the target strength would be 30...read more

Cement can be tested on site using various methods such as slump test, compressive strength test, and temperature monitoring.

• Perform a slump test to measure the consistency and workability of the cement mixture.

• Conduct a compressive strength test by casting cubes or cylinders of cement and testing their strength after a specified curing period.

• Monitor the temperature of the cement during mixing and curing to ensure proper hydration and strength development.

The manufacturing process of cement involves several stages including quarrying, crushing, grinding, blending, and burning.

• Quarrying: Limestone and clay are extracted from quarries.

• Crushing: The extracted materials are crushed into smaller pieces.

• Grinding: The crushed materials are further ground into a fine powder.

• Blending: The powdered materials are mixed in the right proportions to create the desired cement composition.

• Burning: The blended materials are heated in a kiln to...read more