Finals CemaTel Reviewer PDF
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This document contains a set of exam questions on various aspects of concrete and cement, including topics such as fineness, specific gravity, hydration, properties of aggregates, and more. The questions cover different aspects of concrete materials and processes, from composition and properties to applications in civil engineering.
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Final Exam 1. The Blaine air apparatus may be used to measure the fineness of cement in terms of the specific surface, which usually ranges from 300 to 500 sq.m./kg. 2. What is the standard specific gravity of fresh cement? ○ 3.15 3. What liquid is usually used in dete...
Final Exam 1. The Blaine air apparatus may be used to measure the fineness of cement in terms of the specific surface, which usually ranges from 300 to 500 sq.m./kg. 2. What is the standard specific gravity of fresh cement? ○ 3.15 3. What liquid is usually used in determining the specific gravity of cement? ○ Kerosene ○ Gasoline ○ Vinegar 4. What are the compounds that contribute much to the hydration of cement? ○ Tricalcium Silicate ○ Dicalcium Silicate ○ Tetracalcium Aluminoferrite ○ tricalcium aluminate 5. What is the compound responsible for the strength of cement at an early age? ○ Tricalcium Silicate 6. The general term used for the chemical reaction between cement and water is hydration, which is an exothermic reaction, meaning the chemical reaction releases energy through heat. 7. What is the average diameter (in mm) of aggregates if the fineness modulus is 2.5? ○ 0.5mm (not sure) 8. The aggregate affects the concrete in terms of: ○ Cost ○ Strength ○ Durability ○ Workability 9. Crushed aggregates with cubical shapes are ideal for high-strength concrete. A hydrocone crusher is a specialized crusher created for this purpose. 10. If the rebar spacing is 1 inch (25.4 mm), what is the aggregate size (mm) that will produce the most economical concrete? 12.5 mm 25 mm 9.5 mm 19 mm 11. Among the choices, which are the mechanical properties of aggregates? Toughness Strength Specific Gravity Fineness Bond 12. The water inside the aggregates (or absorbed by the aggregates) is not included in calculating the amount of water added to the concrete mix. True 13. Which are the effects of set retarder in a concrete mix? hasten the hardening of concrete Improve Workability Delay the Hardening of Concrete Overcome the Accelerating Effect of High Temperature on Setting (not sure) 14. What admixture do we use to advance the time that a structure can be made in service? Accelerator 15. Addition of aluminum powder in concrete would cause it to expand significantly. True 16. What is the best admixture to produce self-compacting concrete? Superplasticizer 17. What is another term for shotcrete? Gunite 18. What are the advantages of ready-mix concrete? Can Be Used in Congested Sites Good Quality Control no curing is needed Cheaper 19. What is the type of shrinkage caused by water being used up in hydration? Autogeneous 20. Which one below is the acceptable diameter of pipe for pumping concrete if the maximum aggregate size is 19 mm? 30 mm 40 mm 50 mm 60 mm 21. What is the method used to deposit concrete underwater? Tremie 22. What is the property of fresh concrete defining the time required to reach the specified value of resistance to penetration? Setting Time 23. What are the possible causes of the segregation of fresh concrete? Improper Vibration Gap Grading use of river gravel Incorrect Manner of Transport 24. A harsh concrete is a fresh concrete that is difficult to mix. True 25. What are the causes of shrinkage of concrete? Loss of Water Due to Evaporation Loss of Water in Hydration heat of hydration over compaction of concrete 26. What are the different methods of determining the air content of fresh concrete? Pressure Method Gravimetric Method Volumetric Method Penetration Method 27. The concrete stress-strain curve is considered to be elastic up to what percentage of f'c? 50% 28. What are some of the mechanical properties of hard concrete? Compressive Strength Poisson's Ratio Density Modulus of Elasticity 29. What is the term used for the long-term deformation of concrete due to application of sustained load? Creep 30. If the compressive strength (f'c) of concrete is 28 MPa, what is the modulus of rupture of concrete (in MPa) according to the Code? 3.28 MPa 31. The guidelines for standard practice for selecting proportions for concrete? ACI 211.1 32. Which among the statements are false regarding the size of aggregates used in a concrete mix? The bigger the size of aggregates, the more entrained air is present. The bigger the size of aggregates, the less cement paste is needed. The bigger the size of aggregates, the more economical. The bigger the size of aggregates, the greater is its total surface area. 33. An intelligent guess of the optimum combination of ingredients. Trial Mix Initial Mix Mix Design Adjustment 34. Slow-curing cutbacks are usually diluted with non-volatile oil so that it can be used as road dust binder or palliative. True 35. What do you call the hard, brittle, and relatively pure rock asphalt found in vertical rock seams? Gilsonite 36. The grade of asphalt is based on what property? Penetration 37. Which is/are true for blown asphalt? Used as Roof Shingles Used in Expansion and Contraction Joints Manufactured by Blowing Air Used in pavement construction Easily melt under the sun 38. Bitumens are soluble in water because they are primarily made of hydrocarbons. False 39. Which is/are true about asphalt? Residue of Petroleum Cementitious Soluble in Gasoline Does not Oxidize Made of heavy distillates 40. What are the different spray applications of asphalt used in pavement construction? HMAC Prime Coat Fog Seal Tack Coat WMA 41. What are the usual asphalt mixes used in pavement construction? HMAC Blown asphalt WMA Mastic asphalt 42. What do you call the machine that is used to lay asphalt concrete and spreads the asphalt mixture into a uniform layer of the desired thickness of pavement? Paver 43. Which are used in finish rolling in asphalt construction? 3-wheeled roller 3-Axle Tandem Roller Tandem Steel-Wheeled Roller Pneumatic tired roller Trench roller 44. What is the most expensive layer of an asphalt pavement? Wearing Course 45. What is the term used for the foundation soil or a layer of stabilized soil on which the road is supported? Subgrade 46. The shape of the standard specimen used for mix design of asphalt? cube Cylinder beam, cube and cylinder beam 47. What properties of asphalt concrete does the grade of asphalt affect? Thermal Cracking Stripping skid resistance Fatigue Cracking Stability 48. What information can be determined from the Marshall Stability test? Flow Asphalt grade Asphalt ductility Stability 49. If an asphalt mix has low voids, adjustment is done by increasing what component? Coarse Aggregates 50. Which one is not an essential property of an asphalt pavement? Hardness Skid resistance Durability Stability Workability 51. Very high asphalt content in an asphalt concrete mix may result to: Bleeding Stripping Low durability Fatigue cracking 52. What is the term used for stress that will cause rupture at a given time and temperature, usually at high temperatures? Fatigue Creep Thermal failure Stress Rupture 53. The use of chemical reagents, such as carbon monoxide gas, can be used in refining metal. True 54. The characteristic of metal to change shape by pounding or hammering. Malleable 55. The value of the area under the straight line or elastic portion of the stress-strain curve of metal is called the modulus of Resilience. 56. The maximum stress in the stress-strain curve of metal. Rupture point Yield strength Tensile strength Elastic limit Ultimate Strength 57. What do you call the characteristics of metal to resist impact without permanent deformation? Toughness 58. What is an alloy of iron and carbon? Steel 59. What is the principal element of ferrous metals? Iron Ore Oxide Steel Carbon 60. Which one is not a main operation in metal production? open-pit mining calcining distillation galvanizing pyrometallurgy 61. What is the characteristic of metal that allows it to resist scratches or surface cuts? Hardness 62. The carbon content of this steel is from 0.3% to 0.6%. Example of this is the reinforcing steel bars. low carbon steel mild steel high carbon steel medium carbon steel 63. It is possible to make steel alloys with increased strength, toughness, and corrosion resistance that can be used in construction. True 64. Alloy steels used in construction usually belong to the group of alloys that combine with carbon to form carbides. False 65. This impurity may be beneficial to steel in small quantities (0.3% - 1.0%) but detrimental in larger quantities (1.5% and above). nickel phosphorus manganese sulfur slag 66. What is the most undesirable impurity of steel? phosphorus silicon manganese carbon sulfur 67. The two types of furnaces that account for virtually all primary steel production are: basic oxygen furnace and electric arc furnace. 68. Which is/are false about wood? Has natural warmth and can act as a thermal insulator Mechanical properties do not vary between species Excellent strength-to-weight ratio Natural and renewable product Susceptible to termite attack 69. What is the method of seasoning wood by heating to remove moisture using warm moist air or superheated steam? Kiln-Drying 70. Seasoned lumber has many advantages over green lumber, such as: Reduction of weight Increased nail-holding power of the wood Increased checking and warping Increased strength 71. Plywood is usually available in what size? 1.2 m x 2.4 m 4'x6' 4'x8' 3'x8' 72. Tree classification based on growth from the center out by adding concentric layers. Exogenous 73. The central core of the log that is composed of inactive cells and serves only as mechanical support. Heartwood 74. How many board feet are there in 5 pieces of 2" x 6" x 12'? (Rounded to the nearest unit.) 60 75. The chemical component of wood that acts as a bonding agent which glues cells together. Lignin 76. Cracks on lumber going all the way through its thickness, commonly at the ends. Split 77. Which property of wood would affect its strength and shrinkage? All properties listed here Grading Density Moisture content 78. What property of wood affects its nail-holding power? coefficient of roughness moisture content coefficient of thermal expansion specie 79. In Visual Stress Grading of lumber, the problem in identifying the wood species has prompted designers to use what percentage stress grade? 80% stress grade 90% stress grade 50% stress grade 63% stress grade 80. Which are the three principal axes of wood? horizontal axis vertical axis tangential axis longitudinal axis circumferential axis radial axis 81. Latex and enamel are types of what construction material? Paint 82. HardieFlex and Smartboard are brands of what type of board? Fiber cement board 83. Modified true or false: Answer true if the statement is correct but if false, replace the underlined word with the correct one. Original: Steel decks are made by cold-forming structural grade steel sheets into repeating patterns of perpendicular ribs. Modified: Steel decks are made by cold-forming structural grade steel sheets into repeating patterns of parallel ribs. 84. What is the most popular and commonly used form of masonry unit in the Philippines? (Do not abbreviate.) Concrete Hollow Blocks 85. Post-tension steel bars are made of high carbon steel while steel reinforcing bars (rebars) are made of medium carbon steel. True 86. What is the term used for permeable fabrics that are placed under the ground to prevent erosion and are designed to perform soil filtration, drainage, reinforcement, stabilization, and separation of soil layers? Geotextiles 87. Sulfur-impregnated concrete (SIC), which is usually used in making precast concrete, performs poorly in corrosive environments. False 88. Three types of floor tiles were reported in class. Give at least one. (Don't forget to include the word tiles in your answer.) Ceramic Tiles 89. What is added to a concrete mixture to make it translucent concrete? Optical Fibers 90. Glass curtain walls are considered structural members of a building. They add beauty to the structure and act as cladding against wind and other environmental elements. False 91. This construction material, called Acoustic lining, is used to control noise since it can effectively absorb sound energy that collides with it and reflect very little. 92. Carbon Fiber Reinforced Polymer (CFRP) is usually used for waterproofing of reinforced concrete members. False 93. Give at least one type of pipe used in construction (in terms of material) and reported/presented in class. (Do not use abbreviations or include the word pipes.) Polyvinyl Chloride 94. This composite material is made up of mortar and reinforcement, usually a wire mesh or metal fibers. What is this construction material? Ferrocement 95. Modified true or false: Answer true if the statement is correct, but if false, replace the underlined word with the correct one. Original: The minimum yield strength of a grade 60 steel reinforcing bar is 280 MPa. Modified: The minimum yield strength of a grade 60 steel reinforcing bar is 420 MPa. 96. Given the mix design for a 1 cu. m batch of concrete: Material Dry Weight (kg) Wet Weight (kg) Cement 336.07 336.07 Water 205.00 180.28 Gravel 1122.00 1150.05 Sand 618.81 659.03 Answer the following: (Round off volumes in cu.m. to 4 decimal places, round off the rest to 2 decimal places.) a. If the density of fresh concrete is 2250 kg/cu.m., what is the yield for the 20-liter batch? 0.0207 cu.m. b. If the density of fresh concrete is 2250 kg/cu.m., what is the yield for the 1 cu. m. batch? 1.0335 cu.m. c. What should be the adjusted water (for the dry weights) in a 20-liter batch due to the yield and if the measured slump is 30 mm short of the target slump? d. What should be the adjusted water (for the dry weights) in a one cu.m. batch. due to the yield and if the measured slump is 30 mm short of the target slump? e. What is the water-cement ratio of this mix? LQ1: LQ1-SQs LQ2: CEMATEL LQ2 LQ3: LQ3 CEMATEL REVIEWER