TÜV SÜD Civil Site Engineer Interview Questions and Answers

Water absorption in bricks indicates their porosity and quality, typically ranging from 5% to 20%.

• Bricks with lower water absorption (5-10%) are generally stronger and more durable.

• High water absorption (15-20%) can indicate poor quality or excessive porosity.

• For example, clay bricks usually absorb around 10-15% water.

• Concrete bricks may have lower absorption rates, often below 5%.

The maximum slump value for casting typically ranges from 75 to 100 mm, depending on the application and mix design.

• Slump test measures the workability of concrete.

• A slump of 75-100 mm is ideal for structural elements.

• Higher slump values (up to 150 mm) may be used for complex shapes.

• Excessive slump (>150 mm) can lead to segregation of aggregates.

Crossing strength of concrete refers to its ability to withstand loads without failure, crucial for structural integrity.

• Concrete's crossing strength is measured by its compressive strength, typically expressed in megapascals (MPa).

• For example, a standard mix of concrete might have a compressive strength of 25 MPa, suitable for residential structures.

• Factors affecting crossing strength include water-cement ratio, aggre...read more

The sand and cement ratio for brick masonry typically ranges from 1:4 to 1:6, depending on the strength required.

• A common mix for brick masonry is 1 part cement to 5 parts sand (1:5) for general construction.

• For stronger structures, a ratio of 1:4 may be used, especially in load-bearing walls.

• In some cases, a 1:6 ratio is sufficient for non-load-bearing walls or decorative brickwork.

• The choice of ratio also depends on ...read more

Compressive strength of bricks is a measure of their ability to withstand axial loads without failure.

• Compressive strength is typically measured in megapascals (MPa).

• Common bricks have a compressive strength ranging from 3.5 to 7.5 MPa.

• Engineering bricks can have compressive strengths exceeding 20 MPa.

• Testing involves applying load until failure, often using a universal testing machine.

• Higher compressive strength indic...read more

Clear cover is the distance from the surface of concrete to the reinforcement, while effective cover accounts for corrosion and other factors.

• Clear cover is essential for protecting reinforcement from environmental factors.

• Effective cover considers the actual depth of concrete after shrinkage and other factors.

• For example, if the clear cover is specified as 25mm, the effective cover may be less due to concrete shrinkag...read more

M20 grade concrete typically uses a mix ratio of 1:1.5:3 for cement, sand, and aggregate respectively.

• M20 concrete mix ratio: 1 part cement, 1.5 parts sand, 3 parts aggregate.

• Total parts in M20 mix = 1 + 1.5 + 3 = 5.5.

• For 1 cubic meter of M20 concrete, approximately 400 kg of cement, 600 kg of sand, and 1200 kg of aggregate are used.

• Water-cement ratio is crucial; typically around 0.5 for M20 grade.

Modular bricks are standardized bricks used in construction, typically measuring 190mm x 90mm x 90mm.

• Modular bricks are designed for easy handling and uniformity in construction.

• Common dimensions include 190mm (length) x 90mm (width) x 90mm (height).

• These dimensions allow for efficient stacking and alignment in walls.

• Modular bricks can be used in various applications, such as residential and commercial buildings.

Fine sand, typically river or manufactured sand, is used in plastering for a smooth finish and good adhesion.

• Fine sand is preferred for plastering due to its small particle size.

• River sand is commonly used as it is clean and free from impurities.

• Manufactured sand can also be used, providing consistency in grading.

• The sand should be well-graded to ensure a smooth application.

• Avoid using coarse sand as it can lead to a r...read more

Calculating the number of bricks for a 1 square meter wall involves considering brick size and mortar thickness.

• Standard brick size is typically 190mm x 90mm x 90mm.

• Assuming mortar thickness of 10mm, the effective size becomes 200mm x 100mm.

• Area of one brick with mortar = 0.2m x 0.1m = 0.02 sq.m.

• Number of bricks per square meter = 1 sq.m. / 0.02 sq.m. = 50 bricks.

• For a wall of 1 sq.m., approximately 50 bricks are neede...read more