Q: What are the duties or responsibilities of a Civil Engineer?
A: The duties and responsibilities of a Civil Engineer include assisting the Resident Engineer in all aspects of the project, including site supervision and office work. They are responsible for ensuring that the work is of high quality, according to contractual agreements, specifications, and Client/MOT circulars. They must also make draft reports regarding site problems and coordinate with contractors and consultants. Additionally, Civil Engineers organize the duties of site staff, monitor the program according to contract schedules, and keep records of all correspondence and monthly reports. They randomly check lab testing and record it.
Q: If a contractor submits a schedule, how would you check it?
A: As per special specifications, we would check the contractor's main power and machinery available on-site. We would then check the program according to actual activities and correct it if necessary. We would then send the revised program to the contractor for approval.
Q: What is the difference between CPM and Bar Chart, and what are their advantages?
A: CPM or critical path method is a way of making a construction program. It consists of a series of interconnected lines that indicate each activity, and the project is divided into several such activities with a determined time duration, taking into account the number of manpower and equipment. A Bar Chart, on the other hand, is a graphical representation of activities drawn horizontally that shows the sequence, order, and time duration. The main difference between them is that the CPM is based on the average production of equipment and the availability of manpower, while the Bar Chart may not necessarily be based on the list and average production of equipment. The advantages of CPM include better planning, improved scheduling, and the ability to identify critical activities. The advantages of a Bar Chart include ease of understanding and the ability to quickly see progress.
Q: What is the preparation period, and what does the contractor have to do or what will you check during the mobilization period?
A: The preparation period is a three-month period from the date of contract signature. During this time, the contractor has to carry out all survey works, including defining the road center line and fixing leveling marks, drawing terrain cross-sections, and determining the sizes of the cutting and filling sections along the road. They also have to prepare the necessary structural design and submit it for approval by the ministry and engineer, prepare a detailed work program, and set up a workshop location and provision of equipment. They must also specify water resources, material resources, and excavation places and obtain necessary written approvals. During this time, the contractor will also carry out necessary laboratory tests for approval, prepare the drawings pertaining to traffic diversions, and obtain necessary approvals. We would check that all of these activities are being carried out according to specifications and requirements.
Q: How do you calculate the x-sectional area of a road section, and by which method?
A: The average end area method is used to compute quantities, except where the error exceeds plus or minus five percent as compared with the prismoidal formula, in which case the Engineer will direct the use of a more accurate method.
Q: 06 What should be done if a part of the details of work is missing from the drawings and specifications are also silent about such details?
A: If a part of the details or description of any point of work is missing from the drawings and specifications are silent about it, the best generally accepted practice or MOT/Client circulars should be followed by the contractor.
Q: 07 Is there a provision to pay the contractor for the materials that they procure and store at the job site? Can you explain the procedure?
A: Yes, temporary payments can be made to the contractor for certain materials supplied by them for use in the permanent work, provided that the materials are in accordance with the specifications and have been tentatively approved by the Engineer. The payment is within the limits of 75% of the specified cost. The following materials are eligible for temporary payment: cement, reinforcing steel, prestressing steel, road paint, bearing devices, expansion joints, electrical materials, structural steel, and miscellaneous metals. The payment can only be made for the materials actually imported to the site, according to 75% of the market price or 75% of the contract's unit price.
Q: 08 If the asphalt mix temperature at the site is 130˚C, would you allow the contractor to pave if they provide written assurance and take responsibility?
A: No, according to the specification, all courses of bituminous concrete pavements shall be spread and initial coverage or break down and compaction shall be performed when the temperature of the mixture is not less than 140˚C. All rolling shall be completed before the temperature of the mixture drops below 90˚C. Therefore, we cannot allow the contractor to carry out work at a low temperature of 130˚C.
Q: 09 If some work items are available in the drawings, but the BOQ is silent about such items, how will you pay the contractor?
A: If an item of work is missing in the BOQ but is available in the drawings, we will check the specification for the payments. If there is no payment for the item, it will be considered a subsidiary item, such as lean concrete or blinding and tack coat. For items for which payments are mentioned in the specification but are missing in the BOQ, we will prepare a rate analysis for such items of work and send it to the competent authority for approval.
Q: How will you prepare the monthly certificate? What data and quantities will you check yourself and what will you leave for your surveyor and quantity surveyor?
A: The monthly certificate, or Interim Payment Certificate (IPC), contains several parts including a summary and nine bills for various items of work. The surveyor will collect data from the site and provide it to the quantity surveyor who will prepare the quantities and make corrections in the IPC. The Resident Engineer/Civil Engineer will then check the overall IPC, verifying quantities at random and comparing actual progress to the schedule/work program. They will also check the equipment and staff of the contractor as available at the site. The scope of work required under the item "un-classified excavation" mentioned in the general specifications includes separate payment for cut and embankment fill. In case of contractor procuring or bringing material from a crusher plant or quarries and storing it at the site, payment will be made against stored material after verification. Bituminous material should not be applied during rain, dust, or sand storms. The Sand Equivalent test is a rapid field test that indicates the presence or absence of detrimental fine dust or clay-like material in soils or aggregate. If the Sand Equivalent remains low or fails even after adjustment, a hydrometer test will be applied. The effect of leaching by water on concrete includes the precipitation of calcium carbonate on the surface, which can cause disintegration over time.
Q: What is the scope of work required under the item "un-classified excavation" mentioned in general specifications?
A: The scope of work required under the item "un-classified excavation" mentioned in the general specifications includes separate payment for cut and embankment fill.
Q: If a contractor procures or brings material from a crusher plant or quarries and stock stores it at the site and claims payment for these materials while preparing the monthly IPC, will you pay him against the stored material? If yes, then how? Explain and tell the percentage.
A: Payment will be made against stored material after verification.
Q: If a sandstorm or rain is coming and a contractor wants to lay asphalt while 15 dump trucks with asphalt mix are standing at the site, will you allow it? How will you find a solution?
A: Bituminous material for prime coat, tack coat, and fog seal shall not be applied to any surface until the air and surface temperatures are at least 15˚C and rising. It shall not be executed during rain, dust, or sand storms.
Q: What is the Sand Equivalent test? If, after improvement and adjustment in ABC material, the Sand Equivalent remains low or fails, what solution will you suggest? What is the maximum value of the hydrometer?
A: The Sand Equivalent test is a rapid field test that indicates the presence or absence of detrimental fine dust or clay-like material in soils or aggregate. If the Sand Equivalent remains low or fails even after adjustment, a hydrometer test will be applied. If the difference is less than 5%, it will be accepted. If it is more than 5%, the material will be rejected. The reading of the hydrometer has a minimum value of 0.995 and a maximum value of 1.030. The length of the hydrometer is 350 mm, and it is calibrated in grams per milliliter at 20˚C.
Q: What is the effect of leaching by water on concrete?
A: Leaching by water on concrete can cause the leakage of soluble calcium hydroxide in solution through the concrete structure. The reaction between the calcium hydroxide and carbon dioxide will cause precipitation of calcium carbonate on the surface in the form of white deposits. Over a long period of time, this can cause disintegration.
Q: What are the required tests for fresh concrete?
A: The required tests for fresh concrete include yield test, air content, cement content, slump test, and temperature.
Q: Why are the concrete cylinders crushed after 7 days, not for other days?
A: Concrete cylinders are crushed after 7 days to determine the strength gain or development of concrete, and the results should not be less than 75% of the specified strength at 28 days. The concrete is also tested after 28 days because this is the estimated 100% strength development of the concrete.
Q: How do you check the riding quality of a road?
A: The riding quality of a road is checked using an International Roughness Index (IRI) machine in meters per kilometer with selectable length. The operating speed is typically 0.4 m/s. Good leveling and smooth compaction of asphalt by a steel roller and continuous operation of asphalt paving can help obtain good riding quality. There should be no jumping when the car speed is high.
Q: Who receives requests from the contractor?
A: The civil engineer receives requests from the contractor's representative.
Q: How do you control the works of the contractor if they are in progress?
A: The works of the contractor in progress are controlled according to the drawings, special specifications, BOQ, and general specifications.
Q: How do you and your site inspector know that there will be work tomorrow?
A: The contractor has to submit a request 24 hours before the checking, which allows the RE and site inspector to know that there will be work tomorrow.
Q: How do you construct and check the settlement of foundation footing when one is in rocks and the other is in soil?
A: For a foundation footing in rocks, cores are taken to determine the settlement. For a foundation footing in soil, the Standard Penetration Test (SPT) is carried out to check the settlement.
Q: What is SPT?
A: SPT stands for Standard Penetration Test, which is carried out to determine the bearing capacity of the soil, usually on the foundation of bridges and large buildings.
Q: If you are an acting RE, what is the main point you will check in the asphalt and concrete mix design that your ME submitted to you for correction and remarks for approval to MOC?
A: In the concrete mix design, the main points that an acting RE will check before submitting to the MOT for approval include satisfactory test results, compressive strength at 7 and 28 days, minimum cement factor, water-cement ratio within the range, slump of approved trial within specification range, approved admixture and its dosage range, and homogenous wet mix. For asphalt mix design, the main points to check include satisfactory test results, higher stability, air voids, voids in mineral and filler within the range, homogenous mix, and bitumen percentage within the range.
Q: What is the purpose of curing concrete and when do you cure the concrete?
A: The purpose of curing concrete is to maintain a moist environment and prevent the escape of mixing water required for hydration processes. This helps in the development of strength and prevents cracks. The concrete is cured right after the final placement of the concrete mix when the water sheen or mixing water just begins to disappear.
Q: What are the types of curing, what is membrane curing, and what is the rate of application?
A: The types of curing include water curing, membrane curing, steam curing method, and cold weather curing method. Membrane curing is a method of curing concrete using a thin layer of membrane or sheeting that prevents the escape of mixing water from the concrete surface.
Q: How do you make a report?
Ans: To make a report, I would summarize all the daily activities and present them in a clear and organized manner.
Q: How do you check for the preparation of foundation for an embankment?
Ans: To check for the preparation of the foundation for an embankment, the surface where the embankment is to be placed must be scarified to a minimum depth of 20cms, brought to a uniform moisture content within the specified limits, and compacted to the density specified for the overlying embankment before the foundation is prepared to receive the embankment.
Q: What type of material is suitable for an embankment?
Ans: A-5 or better material is suitable for an embankment, with a minimum CBR of 3%.
Q: What type of material is suitable for a subgrade?
Ans: A-1-a, A-1-b, and A-2-4 materials are suitable for a subgrade.
Q: What is a subgrade and what are the requirements for subgrade material?
Ans: A subgrade is the soil foundation that receives the direct traffic loads from the pavement. The requirements for subgrade material are:
- Subgrade material should be A-1-a, A-1-b, A-2-4, or A-2-4 with no rock fragments larger than 10 cm.
- CBR minimum 25%.
- Material should be well graded with sufficient fines to permit compaction & compacting test.
- Two equal layers should be 15 cm each layer.
- Minimum compaction 98%.
Q: What is an Aggregate Base Course (ABC), what material is required, why is layer thickness required, and what are the quality tests required?
Ans: An Aggregate Base Course (ABC) is a layer of material used in road construction that consists of spreading, furnishing, and compacting one or more layers of ABC to the lines, elevations, and thickness shown on the plans and as specified in the specifications on prepared subgrade, sub-base, or existing road surface. The material required for ABC should be clean, hard, durable, sharp angle fragments free from soft, and free from deleterious material. Layer thickness is required to ensure proper compaction and stability. The quality tests required for ABC are:
- Sodium sulphate soundness
- Abrasion
- Sand equivalent
- Atterberg limits
- Flat & elongated pieces
- CBR
- Sieve Analyses
- Fractured faces.
Q: What are the quality requirements for Aggregate Base Course (ABC) material?
Ans: The quality requirements for ABC material are:
- Sodium sulphate soundness 12 max
- Abrasion loss 45 max
- Sand equivalent 45 min
- Liquid limit 25 max
- Plasticity Index 06 max
- Mechanically two fracture faces 90% by weight.
- Flat & elongated pieces 08 max
- CBR for grade I 100 min
- CBR for grade II 80 min
- CBR for grade III 65 min
- Aggregate size for grade I 2″ max
- Aggregate size for grade II 1.5″ max
- Aggregate size for grade III 1″ max
- Compaction 100%.
Q: How do you construct ABC?
- Spread the aggregate base using a spreader box or paver machine.
- Ensure that each layer is compacted to a thickness of not less than 7cm and not more than 15cm.
- Do not spread ABC more than 2000 m² in advance of rolling.
- After the course has been completely compacted, test the surface for smoothness and accuracy of grade and crown.
- Ensure that the finished surface does not vary more than 9 mm from a 5 m straight edge when applied to the surface parallel with and at right angles to the center line.
- Thickness should represent not more than 300 m² by cores.
- If the difference is more than 12 mm, correct such areas by scarifying, adding base mixture, rolling, reshaping, and finishing.
Q: What checks do you make before pouring concrete?
- Check the levels and location of the structure by the surveyor.
- Check formwork and reinforcement as per bar bending schedule.
- Check all equipment of the contractor for pouring concrete.
- Consider weather conditions.
- Check air temperature.
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