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Aramco Questionnaires on Interview:
- Layer thickness before subgrade compaction of soil (loose). Ans: 200 mm
- Maximum concrete temperature before final placement. Ans: 32 degrees Celsius
- Temperature range of asphalt after leaving batching plant. Ans: 139 to 163 deg cel.
- Read about CBR values for all subgrade surface.
- Minimum TDS of water for curing. Ans: 1000ppm
- Minimum TDS of water for mixing concrete. Ans: 500ppm
- Minimum distance between anchor bolts and edge of concrete foundation. Ans: 100mm
- Read about CMU masonry minimum compressive strength
- Minimum size of vertical rebar in the CMU wall. Ans: 12mm
- Minimum stress of tendons for the pre-stressed precast concrete. **Interview Questions:
- Tell about QCP, ITP** Ans: Quality Control Procedure, Inspection Test Plan 2. Tell about work procedures, i.e. foundation works, till inspection to be raised. Ans: Check the work as per approved drawings, MS, project specs if the work is completed and then raise RFI. 3. What is hold point? And witness point? Ans: Hold point means the succeeding work cannot proceed unless the work is approved. Ans: Witness point means the succeeding work can proceed after or during inspection. 4. Situation when there is deficiency in the work during inspection, how it would be resolved to close out. Ans: Rectify immediately and find out what are deficiencies. 5. What is the purpose of surveillance inspection? Ans: To inspect and give your comments as per approved drawing and method of statement during the ongoing activities to have easy approval for the inspection. 6. Procedure for closing out NCR. Ans: Obtain approval of the proposed solution
Ministry of Communication – Interview tips for Site Inspector
1. What are the main points which you will watch where the earthwork is in progress? -Material is not oversized (not more than 8 cm) -Not over 30 cm per layer -Not exceeding optimum moisture content or less (not rubberizing or foaming) -While grading see to it that material is not segregated -Number of passes of roller during compaction, and weight of compactor (8 passes minimum with ½ overlap) -Smoothness of the finish surface of subgrade. Contractor should use 4-m straight edge. Tolerance limit is 6mm for subgrade, 3mm for asphalt. 2. What are the different types of rollers used for the compaction of asphalt? And the function of each? a. Tandem Steel Roller -Initial rolling of asphalt, only 2 passes at ½ overlap -Final rolling to smoothen the surface and to see to it that the edge of the roller not visible on the asphalt b. Pneumatic Tire Roller -To attained the require compaction (8 passes min, not less than 5 tons) 3. What is the thickness of each layer allowed for an embankment and for subgrade? -For embankment; 30cm thick or as otherwise specified -For subgrade; Earth cut – 30 cm to be laid in two layers (15 x15) Earth fill – 40 cm to be laid in two layers (20x20) if possible to attain the required 100% compaction. -Rock cut: 20cm in one layer.
- What is the procedure for starting the first layer of earthworks if the total height of embankment is less than 75cm? -Grabbing and scarifying the area till 15cm and watering it. Removing any unsuitable material then compacting it 5. Suppose the first layer of subgrade was compacted and tested one month back, would you allowed the laying of second layer of subgrade of this work? If not, what will you require the contractor to do? -No, the contractor should clean, spray water and re-compacted until 100% compaction is attained. 6. What is the maximum size of gravel you will allow the subgrade layer? What would be a reasonable CBR for subgrade? -80mm max in subgrade
CIVIL QA/QC QUESTIONAIRE
1. A clear space of ____________ shall be maintained on all sides of the excavation. a. 2 ft b. 3 ft c. 4 ft d.5 ft e. all of the above 2. Shoring shall be installed or sides shall be sloped or benching when the depth of excavation reaches ___________. a. 0.8m b. 1.5m c. 1.2m d. 1.4m e. all of the above 3. Liquid limit and plastic limit test are required for select the material when the percentage passing the #200 sieve is _________. (Liquid & plastic limit test are required if the % passing the #40 sieve is more than 15%) a. 10% b. 14% c. 16% d. (a) & (c) d. all of the above 4. The sufficient thickness for cohesive capping material when sand was used as fill material was a. 150mm b. 200mm c. 250mm d. all of the above e. none of the above 5. What are the two basic type of concrete as per SAES-Q-001? (Write your answer). Structural & **non-structural concrete.
- What is the maximum temperature of concrete that can be poured into a concrete structure?** a. 25 dec cel b. 30 deg cel c. 32 deg cel d. a b, c e. none of the above 7. What is the acceptable temperature of asphalt mix prior to and during placing and compaction? Temperature shall be 139 to 163 degrees centigrade. a. 135 deg c b. 140 deg c c. 163 deg c d. a & c **e. b & c
- The maximum 28 day compressive strength of structural concrete as per SAES-Q-001 was ____** a. 4000 psi b. 4500 psi c. 5000 psi d. all of the above e. none of the above 9. The minimum thickness of concrete slab that is subject to vehicular traffic as per SAES- Q- was ______ a. 100mm b. 150mm c. 200mm d. all of the above e. none of the above 10. Plant scale shall be calibrated _______ times a year and shall be certified by an independent laboratory. a. Two b. three c. four d. five e. none of the above 11. Concrete mixing water shall have no more than _____ ppm total dissolve solids (TDS) a. 300 b. 350 c. 500 d. 1000 e. none of the above
12. The minimum clear distance of anchor bolts or anchor bolts sleeves from the edge of concrete shall be ______ a. 50mm b. 75mm c. 100mm d. 120mm e. none of the above 13. Concrete can be drop freely at a height of ________. a. Half meter b. one meter c. one and a half meter d. a & b e. a & c b. 14. Concrete curing water shall not have more than _______ of total dissolve solids ( TDS) a. 500ppm b. 750ppm c. 1000ppm d. all of the above e. none of the above **TYPICAL INTERVIEW QUESTIONS FOR CIVIL INSPECTOR
- What are the most important element of soil classifications (SAES-A-114)** a. Type of soil, Gradation, and Atterberg limits. The inspector should have a general idea how this limits (liquid limit, plastic and plasticity index correlate with selecting approved Select Fill) 2. What is CBR (SAES-Q-006)? a. California Bearing Ratio. It is a laboratory value that helps determining soil bearing capacity and in classification soil. It is a design parameter however, is a requirement by our standard to verify and check, not knowing what it is indicates the inspector has poor soil knowledge and experience. 3. What id the maximum depth of regular fill lift (layer) prior to compaction (SAES-A-114)? a. 200mm 4. What Is the maximum depth of a fill lift (layer) when manually equipment is used for compaction (SAES-A-114)? a. 100mm 5. What are the project conditions and factors that control compaction (Experience & SAES-A- 114)? a. Proper moisture content b. Compaction of equipment used and number of rolls c. Type of soil d. Confinement of soil (for sand) and stepping of layers of marl and select fill.
11. What is the prime coat and where is it applied (SAES Q-006 & AASHTO)? What is the curing requirement for the Prime coat? a. It is the asphalt bituminous material that is place on the substrate prior to placement of the first asphalt mixture (the blinder course). It must be allowed to cure and soak into the capping layer (usually select fill) b. 24 hours, a good indication that the material cured is when the color turns to pitch black e.i. the brownness is gone. 12. What is Tack Coat (SAES Q-006 and AASHTO)? a. It is the asphalt bituminous material when is applied on existing concrete or asphalt surface to bond the new subsequent asphalt pavement to them. Tack coat is not necessary to place on new asphalt before placing the next layer of asphalt unless it is soiled (dirty). 13. What is the tolerance requirement of sub-grade asphalt surface smoothness prior to placing asphalt (SAES Q-006 and AASHTO)? a. Using a 3 meter edge = 6mm 14. What is the tolerance requirement of finish asphalt surface smoothness (SAES Q-006 & AASHTO)? a. Using 3 meter straight edge 4mm longitudinally, 3mm laterally. **PART 2:
- What is your job requirement as a QC Inspector** a. The answer should content the word “Quality” in it. If his answer indicates he is a foreman or a site engineer, do not hired him, as his mentality focused on the schedule of his boss (The contractor Project Engineer or Manager) and not the Quality. 2. Who will you really work for? a. (This is a loaded question. He should answer that he works for the contractor but serving Saudi Aramco. Meaning his salary comes from the contractor but he is working for us our Quality eyes)
- Would you walk me through the process of initiating an inspection point through the RFI system? He should mention the sequence, which starts with field workers preparing the work item, after the completing the work item, and prior to proceeding with the next step, the foreman notifies the site engineer or the QC inspector directly that the point is ready for inspection, and which point the QC inspector checks it, correct any deficiency that he observed based on his experience, drawing, specifications, standards, etc. then prepare the RFI form then notifies SAPMT that the point is ready. PMT check the point (or whatever) then invites the inspection rep (QA Inspector) to inspect the point. If they ok to proceed, the QA inspector okay
it and the QC inspector notify the field foreman or the site engineer to proceed. If not, the problem is communicated to the site engineer to fix.
4. Tell me about ITP and the QCP? Roads and Bridges Site Inspection Guidelines (Question and Answers) 1. What are the duties and responsibilities of a Site Inspector? -Supervise the actual construction on the site as guided and instructed by the civil or resident engineer -Bear direct responsibility for application of specification on site -Make sure that safety measures are applied by the contractor -Prepare daily work report in addition to memoranda -Not act as a foreman for the contractor -Not change specification and plans 2. Min & max temperature of asphalt at the site of paving? -Min is 139®C, Max is 163®C 3. Min atmospheric (air) temperature prior to paving? -Min is 4®C 4. Min & Max temperature of concrete at the site prior to paving? -Min concrete temperature is 10®C, Max is 32®C 5. Atmospheric (air) temperature allowed for paving? -5®C Min for cold weather -33®C Max for hot weather 6. Min atmospheric temperature prior to spraying MC-1 or MC-2? -Min is 15®C 7. What are the purposes of curing? -To maintain the amount of water in the concrete mix -To minimize hairline cracks
17. What is the purpose of retarder? -To delay initial setting of concrete -To accelerate the effect of hot weather on the setting of concrete 18. What is the purpose of slump test? -To determine the consistency or workability of the concrete mix and to check for the required slump 19. Allowable slumps? -2.5cm to 7.5 cm (for vibrated structure & without additive) -If with additive, slump depends upon the special specifications 20. Type of curing? -Water curing, as in ponding, burlap, spraying, wet sand and wet earth -Membrane curing is a plastic film, liquid membrane curing compound and reinforced paper -Team curing 21. What is plasticizer? -Usually applied at a low water-cement ratio concrete to make workable -Usually use in pre-stressed concrete 22. What is composite structure? -It is a structure composed of two materials as in steel and concrete 23. What is non-composite structure? -It is a structure made of either concrete or steel 24. Types of cement -Type I = Normal or standard cement (for general use) -Type 1-A = Air-entraining cement same as type I -Type II = Moderate Sulfate resistance cement -Type II-A = Air-entraining cement same as type II -Type III = High-early strength cement usually used in pre-stressed concrete -Type IV = Low Sulfate Resistance cement -Type V = High Sulfate Resistance cement 25. What is the effect of seawater on concrete? -It increases the risk of corrosion of rebars -It weakens the strength of concrete -Cracks occur due to the crystallization of salts in the concrete mix
26. Can you use seawater as mixing water in concrete and or embankment? -Yes, if suitable fresh water is not available 27. Two types of pre-stressed concrete -Pre-tensioned Concrete = The tendons are tensioned to a desired force before pouring of concrete, then released after the concrete has attained the desired strength. -Post-tensioned Concrete = The tendons are positioned to their locations, then poured concrete mix. After the concrete has attained the required strength, then the tendons are stressed to the specified force. 28. Minimum compressive strength of concrete before applying force? -At least 350kg/cm 29. What is the minimum strength of concrete before applying force? -300kg/cm 30. Reason behind cracks? -Poor curing practice, poor design, poor vibration which result in segregation, less rebar covering, poor quality of concrete, movement of falsework or forms, higher water cement ratio. 31. What part water-cement ratio plays in concrete? -The lower the ratio the stronger the concrete mix, provided it can be consolidated properly. 32. What are the concrete samples? -The cylinder and the cubes 33. What is the difference between the two and which is preferable? -The difference is in there deformation when subjected to compressive loads. The deformation in cylinder is bigger than in the cube. The cube can withstand bigger loads because of its L/D ratio. But the strength of the cylinder is nearer to the actual strength of the structure being poured than the strength on the cube. That’s why when we use the cube, we multiply the strength that was gotten by a correction factor depending on L/D ratio. While in cylinder there is no correction factor applied for the reason cylinder sample is more preferable. 34. Within how many hours should concrete mix be discharged after leaving the batching plant or after all the aggregates, cement and water are in the mixer? -Within one hour if the mixer is an agitated mixer -Within 30mins if the mixer in non-agitated mixer
-By just looking and smelling, MC-1 smells kerosene and look dull and its thicker, while RC-2 smells benzene (gasoline) and looks shiny and is thinner and dries rapidly.
47. What are you going to do if there is bleeding in MC-1 or if the MC-1 is not dry after 48 hours? -I will apply blotting by spreading sand on wet portion only when removing the excess by rake or any suitable equipment 48. What is rutting? -It is the longitudinal settlement of asphalt pavement due to heavy loads of the vehicles passing the road 49. What are the remedies to prevent of minimize rutting? -To limit or minimize the loads of vehicle -To make the gradation of aggregates coarse but conducive to the project -To lower the asphalt content and/or lower the asphalt penetration (as from 60-70 to 40 -50) -To follow the instruction of the MOC as to the limit of air voids which is 3-5 with 4 as the median and actual air voids to be gotten 50. What is the purpose of MC-1 (Medium Curing Cutback Asphalt)? -To stabilize or seal the granular surface of subgrade and to promote bonding to bituminous surface. 51. What is the purpose of RC-2 (Rapid Curing Cutback Asphalt)? -To ensure or promote bonding between the previously laid asphalt pavement and the newly paved layer 52. Minimum and maximum overlapping of asphalt in longitudinal and transversal joints? -For longitudinal joint 15 to 30 cm 53. Why do you overlap? -To prevent cracking at the longitudinal joint 54. What will happen if your asphalt content is more than 0.3%? -It will be more than the required limits and bleeding will occur and thereby weakening the pavement 55. What is the maximum loss of stability for asphalt? -25% 56. What is the maximum variation of asphalt content? -±0.3% from the approve asphalt content
57. Types of compaction and moisture ranges? -Type AAA = 100% compaction, 78% relative density Moisture ranges = MR 3 (Moisture shall not be lower than 3% of the optimum moisture) -Type AA = 95% compaction, 74% relative density Moisture ranges = 0 (moisture shall be ±5% of optimum moisture) -Type A = 90% compaction, 70% relative density 58. Temperature of asphalt pavement before breakdown or initial rolling? -120®C or as what we get from the trial test 59. Heating temperature of MC-1 and RC-2 before spraying? -MC-1 should be heated to 50 - 80®C -RC-2 should be heated to 65 – 95 ®C 60. Rate of application of MC-1 and RC-2? -MC-1 = It is 0.65 – 1.75 liter/m -RC-2 = It is equal or less than 0.25 liter/m 61. What are the two types of asphalt batching plant? -Batching type = It is easy to control and it is batch by weight -Continuous type = It has a greater output 62. What is SPT? -Standard Penetration Test, it is usually made to evaluate the bearing capacity of the soil 63. What is Bleeding? -It is the flow of water in the mix or on to the surface of the mix because of the settlement of the mass of concrete mix. 64. How do you cure cylinder sample? -Cylinder samples are cured in laboratory, in water tank saturated with lime at 23±1.7®C. -It is also advisable to cure in the field, same as the structure being represented. 65. What are the precautionary measures if the air temp is greater than 33®C? -Make shades; cool the water by using ice cubes -Spray the aggregates specially the coarse with cold water -Wet the forms and reinforcement
- What is the pattern of rolling asphalt pavement?
SOILS
73. Classifications of Soils? A-1 = gravelly or sandy soil with some stone fragment A-2 = silty or clayey gravel and sand A-3 = sand dunes A-4 / A-5 = silty soil A-6 /A-7 = clayey soil 74. What is California Bearing Ratio (CBR)? -It is the test use to find bearing capacity of soil compacted at optimum moisture content and at a different densities (10, 30, 65 blows) 75. What is Proctor or Moisture-Density Test? -It is the test use to find the moisture and density relation of a soil when compacted at laboratory 76. What is the distance of borrow pit from the structures? -Downstream: Min is 200 meters or as otherwise specified
- What is the distance of borrow pit from roadway toe or embankment? -Min is 30 meters from the toe of embankment.
- Study the programing of works specially pouring of concrete, number of mixers, volume of concrete to be poured and manpower requirements. 79. What is the test for rock fill? -It is by consolidated in which grid point are made and then let the roller passed, then elevation of points are taken, then again passing the roller ad elevations of points taken. The difference in elevation between the passes shall not vary from 0 to 3 centimeter. 80. What is the maximum size of rocks use in rock fill? -Not more than 60cm (see the green book) 81. What is the rock fill allowed? -At least 60cm (or see the green book) 82. What are the difference between the Modified and Standard Proctor (using same 6 inches mold)?
-The difference is in their compacting effort. Although its layer is compacted (5 layer) is compacted 56 blows, but the weight of the hammer of standard is 5.5lbs with 12- in drop while that of modified is 10lbs and 18- in drop.
83. What is the difference between the CBR5 and CBR 10? -CBR 10 has more strength than CBR 5.
- For instance in embankment you have 1x1x0.2m and have moisture of 0.2% but at the laboratory you have 8%. How many liters of water you need? Density of soil is 2 Tons/m Solution: Volume = 0.2% Water needed = 8-2 = 6% Weight = Vol. x Density = 0.2 m3 x 2 T/m3 = 0.4 Ton = 400 kg Since 1 kg = 1 liter for 4®C temp Then, water need = 0.06 x 400 kg = 24 kg = 24 liters 85. For instance, it rain the whole night and your aggregates and sand were wet. How do you find the water? -I should inform the Material Engineer so that he will check the aggregates and the moisture 86. What kind of soil you use in subgrade? -A-1-a / A-1-b / A-2-b 87. How about embankment? -Any suitable material like A-1 /A-2 / A-3 / A-4 / A-5 /A- 6 88. Can you use rock fill for backfilling of structures? -No, because it will damage the structure 89. What material are you going to use for backfilling the structures? -Granular materials like A-1 or A- 90. How do you perform slump test? -Take sample from the concrete mix, put in the mould and rod it 25 times each 3 layer, for equal three layers 91. What is the temperature of asphalt required to stop rolling? -80 to 90®C 92. How do you know that the contractor is using the right mixture of aggregates? If the aggregate is 30% natural and 70% crushed sand, not using the control room or the scales. -Close all the automatic feeders except the natural sand and let it flow for a certain time, say 30 seconds, then compute the quantity at 30 seconds, then make the same steps as to the crush sand, this time the bin for natural sand is closed and the time for flowing is 70 sec. then compute the quantity of crush sand.
