20+ NACL Industries Interview Questions and Answers

Only 1 set of cube sample is taken at a casting of concrete of 5 or less than 5 Meter cube to save cost and time.

• Taking multiple samples would increase the cost of testing.

• The strength of concrete is usually consistent within a small volume.

• ASTM C31 allows for only 1 set of samples for small volume concrete.

• If the first set of samples fails, additional samples can be taken for verification.

Slump for casting of concrete is measured using a cone. Slump value may decrease as height increases in high rise buildings.

• Slump is measured using a cone and the difference between the height of the cone and the height of the concrete after it settles is the slump value.

• As height increases in high rise buildings, the pressure on the concrete increases, which may cause the slump value to decrease.

• To maintain the desired slump value, additives such as plasticizers or superplas...read more

The right bonding agent for recasting of concrete after rain would be a polymer-modified cementitious bonding agent.

• The surface should be cleaned and dried before applying the bonding agent.

• The bonding agent should be applied in a thin layer using a brush or roller.

• The recasting of concrete should be done within the specified time frame mentioned by the bonding agent manufacturer.

• Examples of polymer-modified cementitious bonding agents are SikaLatex R and Ardex P 82.

Shear force is the force perpendicular to the beam and bending moment is the torque that causes bending of the beam.

• Shear force is calculated by finding the algebraic sum of all the forces acting on one side of the beam.

• Bending moment is calculated by finding the algebraic sum of all the moments acting on one side of the beam.

• Shear force and bending moment diagrams are used to visualize the distribution of these forces along the length of the beam.

• These calculations are impor...read more

Slump test is a concrete testing method to measure the consistency and workability of fresh concrete.

• Slump test is performed by filling a mold with fresh concrete, then removing the mold and measuring how much the concrete slumps or settles.

• The result of the slump test indicates the workability of the concrete mix - a higher slump value indicates higher workability.

• The slump test is commonly used in construction to ensure the concrete mix meets the desired consistency for pro...read more

The process of brick work involves laying bricks in a specific pattern using mortar to create walls or structures.

• Prepare the surface by cleaning and dampening it

• Lay a bed of mortar on the surface

• Place the bricks in the desired pattern, ensuring they are level and aligned

• Use a trowel to add more mortar between the bricks to secure them in place

• Repeat the process for each layer of bricks until the desired height is reached

• Finish by filling any gaps with mortar and smoothing th...read more

Minimum cement required for M30 grade of concrete is 320 kg.

• M30 grade of concrete requires a minimum cement content of 320 kg/m3

• The cement content may vary based on factors such as water-cement ratio, aggregate type, and quality of cement used

RCC road construction involves using reinforced concrete for durability and strength.

• RCC stands for Reinforced Cement Concrete

• Specifications include using high-quality cement, aggregates, and steel reinforcement

• Proper compaction and curing are essential for durability

• Thickness of the RCC road depends on traffic load and subgrade conditions

• Joint spacing should be as per design specifications

Construction materials are substances used for building and construction purposes.

• Construction materials include cement, concrete, bricks, steel, wood, and glass.

• Cement is a binding agent used in the production of concrete.

• Concrete is a mixture of cement, sand, gravel, and water, used for construction.

• Bricks are rectangular blocks made of clay or concrete, used for building walls.

• Steel is a strong and durable material used for structural purposes.

• Wood is commonly used for fra...read more

The unit weight of 16mm steel is approximately 0.615 kg/m.

• Unit weight is crucial for calculating the total weight of steel in construction.

• For 16mm diameter steel bars, the unit weight is about 0.615 kg/m.

• Example: A 12-meter long 16mm steel bar weighs approximately 7.38 kg (0.615 kg/m * 12 m).

• Unit weight can vary slightly based on the steel grade and manufacturing process.

Piling is a construction technique used to strengthen the foundation of a building by driving piles into the ground.

• Piling involves driving long, slender columns (piles) into the ground to provide support for structures.

• The process starts with site investigation to determine soil conditions and load-bearing capacity.

• Piles can be made of concrete, steel, or timber, depending on the project requirements.

• Piles are driven into the ground using various methods such as impact hamme...read more

The size of covering block is determined based on the type of structure and its requirements.

• The size of covering block is usually specified in the design drawings or specifications.

• It is important to consider the dimensions and spacing of reinforcement bars when determining the size of covering block.

• The covering block should provide adequate protection to the reinforcement bars from fire, corrosion, and other environmental factors.

• The size of covering block may vary dependi...read more

Building construction activities include excavation, foundation work, framing, roofing, electrical work, plumbing, and finishing.

• Excavation: Digging the foundation and preparing the site

• Foundation work: Pouring concrete and setting the foundation

• Framing: Building the structure's skeleton with wood or steel beams

• Roofing: Installing the roof materials

• Electrical work: Wiring the building for electricity

• Plumbing: Installing pipes and fixtures for water and sewage

• Finishing: Adding...read more

Segregation is the separation of different components of a mixture based on their physical properties.

• Segregation occurs when particles of different sizes, shapes, or densities separate from each other.

• For example, in a concrete mix, larger aggregates tend to settle at the bottom while smaller particles rise to the top.

• Segregation can also occur in granular materials like sand and gravel during handling and transportation.

• Proper mixing and handling techniques can help prevent...read more

The length of development refers to the duration it takes to complete a project or task.

• The length of development can vary depending on the complexity of the project.

• Factors such as team size, resources, and scope can also impact the length of development.

• It is important to set realistic timelines and milestones to ensure efficient development.

• For example, a simple website development project may take a few weeks, while a complex software application may take several months o...read more

CMDI and HDPE are two different types of plastic materials used in various applications.

• CMDI stands for Chlorinated Polyethylene Modified Polyethylene and is a thermoplastic elastomer used in wire and cable insulation, automotive parts, and roofing membranes.

• HDPE stands for High-Density Polyethylene and is a thermoplastic polymer used in packaging, pipes, and construction materials.

• CMDI has better resistance to chemicals and weathering than HDPE.

• HDPE has better stiffness and ...read more

Transmission line construction involves planning, design, material procurement, site preparation, tower erection, conductor stringing, and testing.

• Planning involves route selection, environmental impact assessment, and obtaining necessary permits.

• Design includes determining tower locations, conductor size, and insulator type.

• Material procurement involves sourcing towers, conductors, insulators, and hardware.

• Site preparation includes clearing vegetation, leveling land, and set...read more

The density of steel typically ranges from 7.75 to 8.05 g/cm³, depending on its composition and alloying elements.

• Density varies with different types of steel; for example, stainless steel is denser than carbon steel.

• Common structural steel has a density of about 7.85 g/cm³.

• Density affects the weight of steel structures; heavier steel can lead to stronger but more expensive constructions.

• Steel's density is crucial in engineering calculations for load-bearing applications.

BBS preparation involves calculating quantities of steel reinforcement required for construction projects.

• Start by studying the structural drawings and specifications provided

• Identify the different structural elements like beams, columns, slabs, etc.

• Calculate the total length of each type of reinforcement required

• Use standard formulas and codes to determine the quantity of steel bars needed

• Prepare a detailed Bill of Quantities (BOQ) listing all the steel reinforcement materia...read more

pH value measures the acidity or alkalinity of a solution on a scale from 0 to 14.

• pH 7 is neutral (e.g., pure water).

• pH < 7 indicates acidity (e.g., lemon juice, pH 2).

• pH > 7 indicates alkalinity (e.g., baking soda, pH 9).

• pH is logarithmic; a change of 1 unit represents a tenfold change in acidity/alkalinity.

• pH affects chemical reactions, biological processes, and environmental conditions.