ANSWERS TO INTERVIEW QUESTIONS (52-100)

 Answers to Questions 52-100 in Previous Blog (Questions for Project Manager)

52. Water-Cement Ratio

The water-cement ratio is the ratio of the weight of water to the weight of cement used in a Concrete mix. A lower ratio leads to higher strength and durability, but make the mix difficult to work - Low workability of Concrete mix. Work ability can be increased with the use of admixtures.

53. What is Hybrid Foundation?

A Hybrid foundation consists of both soil supported mat and piles, usually for High rise buildings. This type of foundation is helpful in reducing the amount of settlement.

54. What are the various tests for checking Brick quality?

a) Water absorption test: Dip the brick for 24 hrs. in water. For 1st class brick, weight of brick should not exceed 20% increase after 24 hrs. 22.5% for 2nd class and 25% for 3rd class.

b) Compressive strength test: Test to determine the load carrying capacity of bricks under compression with CTM. As per IS:3495. Compressive strength for 1st class bricks - 105.Kg/Cm2, 2nd class bricks- 70Kg/Cm2, Country bricks - 35Kg/Cm2

c)Hardness test: Scratch a brick with nails. It should be scratch free.

d) Soundness test : Struck two bricks- with one another, metallic sound should come and brick should nor break.

e)Efforescense test: To check any soluble salts in bricks, dip brick in water for 24 hours and dry in shade. Then check for any white or grey color deposits which are soluble salts.

Other tests are Color, structure, shape and size. All should be perfect.

55. What is the minimum diameter of steel in Columns?

12 mm

56. IS Codes for Concrete and Reinforcement

 IS:456 ; 10262, SP 23 - Codes for designing concrete mixes

IS: 1199 - Methods of sampling and analysis of Concrete

IS: 2502-1963 - Bending and Fixing of Bars for Concrete Reinforcement

Chair rod

57. Chair rods

Chair rods should be min. 12mm dia. and max. spacing is 1.0 m or 1 no. per 1 Sqm.

58. Binding wire requirement for steel reinforcements

8 Kg/MT

59. Stripping (deshuttering) time for formworks after laying concrete

For Columns, walls, Vertical form works : 16-24 Hrs.

Roof spanning upto 4.5m : Min. 7days

Roof spanning above 4.5m : Min. 14 days

60. Cube Samples

Upto 30 Cum - 3 nos. 

Above 50 Cum - 4+ 1no. addition sample for each 50 Cum.

The test results of the samples shall be the average of the strength of three specimens. The individual variation should not be more than +/- 15% of the average. If more variation, samples are invalid.

61. Compressive strength of Concrete

In 3 days - 45%

     7 days - 67-70%

   14 days - 85%

   28 days - 100%

62.Clay and silt content in Sand

As per IS 383:1970, Clay and silt should not exceed 3% by weight and 8-10% by volume. For Crushed sand 15% by volume.

63. Calculation of Materials required for 1Cum. of Concrete mis 1:2:4 (M15)

Add 50% for wet concrete then, it is 1,5Cum.

1,5/(1+2+4) = 0.214 Cum

Volume of Cement - 1Cum = 1440Kg/50= 30 Bags.

Cement reqd. = 0.214x30 = 6.42 bags

Sand reqd. = 0.214x2 = 0.428 Cum

Aggregate reqd. - 0.214 x4 =0.856 Cum

64. Target strength of Concrete M25

As per IS 10262:2009, Target strength fck = 25+1.65s (Std. deviation s =4)  

Then, Target strength is 25+(1.65x4) = 31.6 N/mm2

65. Cement required for M20, M25 &M30

For M20 mix, cement required : 320kg/cum, for M25 : 340kg/cum & M30 : 380kg/Cum

66. Antitermite treatment

Antitermite treatment is the chemical application in soil, masonry, wood and electrical features to provide protection from Termites before and after construction. The Chemical used for Antitermite treatment is Chloropyriphos 20% (Lindane is another chemical) with ISI certification in India.

Diluting 5 Litre chemical with 95 litre of water and usage is 7.5 Sqm. per litre-diluted.

67. Conversion factors for Sqm to Sft, Cum to Cft, Cum to litres, Acres to Sqm and sft.

       1 Sqm = 10.763 Sft. (1m= 3.28feet)

       1 Cum = 35.314 Cft

       1 Cum = 1000 Litres

       1 Acre = 4046.87 Sqm = 43560 Sft.

68. Materials used in Expansion joint in Columns

Polysulphide compound , polystrene board are most commonly used in India

69. Carpet area, Builtup area and Super builtup area

Carpet Area : It is the area enclosed within walls, does not include thickness of inner walls also. 

Builtup Area : It is the carpet area plus the thickness of walls and the balcony. This will be around 10% more than carpet area.

Super Builtp area : It is builtup area plus proportionate area of common areas such as lobby, lift, shaft, stair, etc. Usually 25% more than the builtup area.

70. Q.A & Q.C

Quality Assurance (Q.A) is a set of activities for ensuring quality in the processes by which works are done. Providing Construction methodology for each activity is part of QA.

Quality Control (Q.C) is a set of activities for ensuring quality in works. It is used to verify the quality of Product. Providing Construction Checklists  for each work is part of QC.

71. What is the IS Code of practice for General Construction in Steel?

IS: 800

72. Which test is conducted to determine the bearing capacity of soil?

Plate Load Test - To determine the ultimate bearing capacity of the ground and the likely settlement under a given load.

Hook length

73. What is the Minimum hook length in stirrups as per IS Code?

75mm

74. Which Apparatus is used for testing consistency in Cement?

Vicat apparatus is used to determine consistency and initial/final setting times of cement and mortar pastes.

75. What is soundness test of cement?

Soundness of Cement is the ability of  a hardened paste to retain its volume after setting. The test for that is 'Le Chatlier Apparatus Test'. In the Soundness Test, a specimen of hardened cement paste is boiled for a fixed time so that any tendency to expand is speed up and can be detected.

76. Number of Bricks used in 1 Cubic meter of Brick work?

      500 Nos.

77.Tell some Project Obstacles/Hindrances for which affects progress very much?

No Proper Planning, Inadequate Funding, Material supply problems, Supplier quality issues, Lack of Team spirit, Poor communications, etc.

78. What is PPE?

       Personal Protective Equipment

79. What are the PPE's mandatory at site?

Safety Helmets, Safety Jackets, Shoes, Safety Belts and Lifelines, Safety nets, etc. Goggles for Eyes protection and face mask while, Hacking, welding, glass cutting, chipping or drilling operations.

80. What is the minimum age required for workers?

      18

81. What is Mivan Technology?

Mivan is an aluminum formwork system.

82. What are the types of Scaffolding in Construction?

a) Single Scaffolding / Brick layer Scaffolding

b) Double Scaffolding / Mason's Scaffolding

c) Steel or Tubular Scaffolding

d) Cantilever Scaffolding / Needle Scaffolding

e) Suspended Scaffolding (Used for repairs, paintings)

f) Trestle Scaffolding ( A platform is supported through the movable ladders in trestle)

83. What are the elements of steel scaffolding?

 a) Standards (Vertical tubes)

b) Ledgers ( Horizontal tubes)

c) Transforms (Horz. tubes placed across and perpendicular to Ledgers)

d) Cuplock is another system

84. List out the Potential risk factors for workers on the construction site?

• Falls from Heights
• Scaffold and Trench collapse
• Electric shock and arc blast
• Repetitive motion injuries
• Not using PPE correctly

86. What are the types of Construction Project Plans?

1. Design & Drawing Plan
2. Time Plan
3. Manpower Plan
4. Material Plan
5. Construction Equipment Plan
6. Finance Plan
7. Quality Plan
8. Safety Plan

87. What is OSHA compliance?

OSHA stands for Occupational Safety and Health Act. Its motive is to fulfill the health and safety requirement of employees and workers. It is the standard adopted by USA.

88. What does a construction cost covers and what does not?

A Construction cost covers material, labour, equipment and services, contractors overhead and profit and other direct construction costs. While, it does not cover compensation paid to the Architect, Consultant or Engineers, cost of the land and other cost that is owner's responsibility.

89. What are the Responsibilities of a Project Engineer?

• Maintaining Drawings
• Technical Supervision of ongoing work
• To control wastage and to improve the quality of workmanship
• To calculate the requirement of different materials and submit the indent well in advance.
• To workout the labours, tools and equipment and inform PM
• To communicate all necessary instructions to supervisors and departmental labour.
• To assist PM to prepare bills of Contractors and submit the measurements
• To discuss the technical problems, issues in drawings and execution difficulties at site meeting.
• To submit DPR, weekly reports and maintaining checklists and documents

90. What are the responsibilities of a Project Manager?

• Preparing Schedules, Materials, labour and cost Planning
• Organising the Execution Team
• Selection of sub-contractors and vendors
• Samples submission and get approval from client
• Monitoring the progress of work as per schedule and maintaining quality
• Cost control is the major responsibility of PM
• Motivating and rewarding the team members to achieve the target
• Submitting Contractors bills, vendors bills and MIS Reports in time.
• Conducting site meetings regularly and sending the minutes to all stakeholders
• Implement the Safety Procedures and assure safety to all
• managing the Project Risks and local issues

91. What is RFI?

RFI is Request For Information to seek the clarification of plans, drawings, specifications and agreements. RFI is a formal written process in which parties, such as the contractor, Architect, designer and Consultants clarify the information gaps in Construction doccuments.

92. What is the difference between RFI & RFP?

A Request For Information (RFI) is used when the owner wants contractors to provide potential solutions, while a Request For Proposal (RFP) is used in a bidding process to solicit offers for a project.

93. Which are the causes of cracks in concrete?

• Concrete expands and shrinks due to temperature differences
• Settlement of structure
• Insufficient vibration at the time of laying of Concrete
• Improper cover provided during concreting
• High water-cement ratio (exceeding 0.5)
• Due to corrosionof reinforcement steel.

94. What are the prevention measures to avoid cracks in concrete?

• Maintain correct Water-cement ratio as per design mix
• Proper mix design and use of quality materials
• Proper placement and vibration of concrete
• Proper finishing of Concrete surface with flat troweling. Don't finish the concrete when there is bleed water on the surface
• Avoid overworking the concrete, especially with vibrators
• Providing proper control joints in concrete
• Proper curing of concrete
• Inspect the formworks from starting to deshuttering

95. What is the role and responsibility of a Quantity Surveyor?

Quantity Surveyor calculates the costs, material, manpower and equipment costs. He is also involved in planning, billing and contracting related jobs which are mainly involved in the construction cost calculation.

Responsibilities of QS:

• Estimating
• Cost planning
• Preparing, negotiating and analysing costs for tenders and contracts
• Procurement advice
• Preparing Bill Of Quantities (BOQ)
• Monitoring Budget
• Preparation of payment invoice and certification
• Assessment of variations and disputes resolution

96. What is Green Building? 

Green Building - also known as sustainable or high performance building is the practice of

• increasing the efficiency with which buildings and their sites use and harvest energy, water and materials; and
• Protecting and restoring human health and the environment, throughout the building life cycle: Design, Construction, operation, maintenance, renovation and deconstruction.

97. What are the components of Green Building?

• Energy Efficiency and renewable energy
• Water Efficiency
• Environmentally preferable building materials and specifications
• Waste Reduction
• Toxics Reduction
• Indoor Air quality
• Smart growth and sustainable Development

98. What is HSE?

HSE - Health and Safety Executive , is an independent regulator that aim to prevent work-related death, injury and ill-health.

99. What are the skills required for a Project Manager?

• Project management
• Technical Skills (designs, specifications and drawings)
• Planning and Organising
• Leadership skills
• Critical thinking skills
• Visualisation skills
• Communication skills
• Risk management

100. What are the requirements to become a Successful Project Manager?

The successful PM will have the knowledge in the following:

1. IS Codes

2. Using survey instruments 

3. Design and Drawing

4. Bar bending Schedule

5. Estimation and Quantity Survey

6. Quality Control

7. Testing of Building Materials

8. Soil Investigation

9. Site safety management

10. MIS Reports

11. Computer Knowledge in Autocad, MS Projects, MS Office, Internet usage. (ERP is more useful)