Civil Technology Nov 2012 Memo Eng_hlayiso.com_.pdf

Downloaded from hlayiso.com GRAAD 12 NATIONAL SENIOR CERTIFICATE GRADE 12 CIVIL TECHNOLOGY NOVEMBER 2012 MEMORANDUM MARKS: 200 This memorandum consists of 15 pages. Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 2 DBE/November 2012 NSC – Memorandum QUESTION 1: LO3 AS 1, 2, 4, 5, 7, 10 1.1 A flat plate with many spikes used in 1.1.1 D roof-truss construction √ Longest vertical member that determine 1.1.2 H the height of the roof truss √ A length of material used to conceal the 1.1.3 B gap between the wall and the ceiling √ Is used to cover the gap between the 1.1.4 G roof covering at the highest point of the roof √ Slope/angle/fall of the roof √ 1.1.5 C ONE '√' FOR EACH CORRECT ANSWER. Do not penalise the candidate if he/she has written the description. (5) 1.2 1.2.1 √ √ Simple supported slab Note: If a candidate show columns as support, it will also be correct. (2) 1.2.2 √ √ Cantilever slab (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 3 DBE/November 2012 NSC – Memorandum 1.3 Key voussoir √ Extrados √ √ √ √ √ √ Rise √ Intrados Span √ 1 Mark to be given if voussoirs are vertical lines. ASSESSMENT MARKS LEARNER'S CRITERIA MARK Voussoirs 3 Key voussoir label 1 Brickwork 1 Rise 1 Span 1 Intrados 1 Extrados 1 TOTAL 9 (9) 1.4 1.4.1 A Eaves/Fascia/tilting batten/overhang √ 1.4.2 B Rafter/Full truss √ 1.4.3 C Ridge/ridge beam √ 1.4.4 D Hip rafter √ 1.4.5 E Half truss or common rafter √ 1.4.6 F Jack rafter/Short rafter √ 1.4.7 G Valley/valley gutter √ (7) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 4 DBE/November 2012 NSC – Memorandum 1.4.8 Gable roof √ (1) 1.4.9 1 400 mm or 1 350 mm √ (1) 1.5 1.5.1 Hemp or TFT tape (Teflon tape)/thread tape/yarn √ (1) OR ANY OTHER ACCEPTABLE ANSWER (silicone not accepted) 1.5.2 Cover the threaded part of pipes with teflon tape or hemp in a clockwise direction. √ Screw in a straight socket (fitting) to the thread on one pipe using two monkey wrenches. √ Screw in the second pipe (threaded part) into the other side of the straight socket (fitting) using two monkey wrenches. Tighten properly. ANY TWO OF THE ABOVE (2) [30] Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 5 DBE/November 2012 NSC – Memorandum QUESTION 2: LO3 AS3, 4, 5, 7 2.1 2.1.1 A Floor slab √ B concrete (symbol for concrete) √ C Reinforcing mesh/main bars √ D Shutter board/soffit board √ E Bearer/Joist √ F Prop/post/pole √ G Wedges √ H Sole plate √ (8) 2.1.2 Concrete is weak in tensile strength and the most √ tension in the floor slab will occur at the bottom due to bending and the reinforcing will serve no purpose when placed on the top. √ (2) 2.1.3 G – To assist with the alignment of formwork; √ to secure the prop in position; to ease dismantling ANY ONE OF THE ABOVE (1) 2.1.4 H – To prevent props from sagging; √ to distribute the load to the load-bearing surface ANY ONE OF THE ABOVE (1) 2.2 2.2.1 Main bars – to act against the tensile forces. √√ (2) 2.2.2 Stirrups/Binders √ (1) 2.3 CRITERIA STRIP FOUNDATION SHORT BORED PILES Preparation of Trenches are dug by Pile holes are foundation workers using shovels drilled into the and picks or earth with an auger mechanical diggers √ type bit or drill √ Concrete filling Concrete is poured by Concrete is forced hand using a into the hole by wheelbarrow or by gravitational forces ready-mix √ √ (4) 2.4 2.4.1 1,788 m – 1,482 m √ or 1, 482 m – 1,788 m = 0,306 m √ = -0,306 m (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 6 DBE/November 2012 NSC – Memorandum 2.4.2 1,788 m – 1,526 m or 1,526 m – 1,788 m √ = 0,262 m or – 0,262 m√ (2) 2.4.3 Intermediate sight √ (1) 2.4.4 Rise √ (1) 2.5.1 and Nail √ 2.5.2 Timber roof track/Ceiling track √ Brandering √ √ √ √ Ceiling board √ √ √ Cornice Cladding √ √ Timber strut FIGURE 2.5 ASSESSMENT CRITERIA MARKS Brandering 1 Ceiling board 1 Top rail/Timber roof track/ceiling track 1 Nail/Screw 1 Timber strut vertical 1 Cladding 1 Cornice 1 Any three labels 3 Total 10 (10) 2.5.3 Gypsum board √ Chipboard/Veneered board √ Supawood/Medium-density fibre board Hardboard/Masonite Plywood Shutter board SA Pine ANY TWO OF THE ABOVE OR ANY OTHER ACCEPTABLE ANSWER (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 7 DBE/November 2012 NSC – Memorandum 2.6 Check power tool cable for damage. √ Ensure that the power tool cable lies outside the working area. √ See that the power supply is properly earthed. Don't work near water with power tool Moving part, Must be kept away from the body. Switch off power supply and disconnect the power tool when making adjustments. Hold power tool securely and firmly when using it. Remove all jewellery and loose clothing. Use safety goggles to protect your eyes. Report any defects immediately. ANY TWO OF THE ABOVE OR ANY OTHER ACCEPTABLE ANSWER (2) 2.7 Square shape √ (1) [40] Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 8 DBE/November 2012 NSC – Memorandum QUESTION 3: LO 3 AS 5, 8 3.1 3.1.1 B √ (1) 3.1.2 A √ (1) 3.1.3 C √ (1) 3.1.4 C √ (1) 3.1.5 B √ (1) 3.2 ADVANTAGES DISADVANTAGES Easily accessible √ Contamination from surface Cheap √ pollution. √ Water supply is reliable √ Although relatively reliable, it can dry up. √ Children can fall into the primitively dug well. √ Obtaining water from a cranked windlass can be slow ANY OTHER ACCEPTABLE ANSWER (6) 3.3 3.3.1 A Rodding eye / cover √ B Pipe (110 mm) √ C Junction (45°) √ (3) 3.3.2 Direction D √ (1) 3.3.3 It is for cleaning purposes so that the cleaning rods can enter the sewer line √ For easy access to the main sewer pipe. ANY ONE OF THE ABOVE (1) 3.3.4 Gives access to the drain pipes √ Prevents foul gasses from the sewerage system entering the atmosphere Prevents rain water, dirt, dust entering the sewer line For safety purposes ANY ONE OF THE ABOVE OR ANY OTHER ACCEPTABLE (1) ANSWER 3.3.5 Cheaper than installing a manhole √ Smaller and look neater than a manhole √ ANY OTHER ACCEPTABLE ANSWER (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 9 DBE/November 2012 NSC – Memorandum 3.4 √ A Bedroom 2 Kitchen DB√ Lounge B √ TV room Bedroom 1 E √ Garage √ √ C F D √ FIGURE 3.4 (7) 3.5 Septic tank √ – Bacterial action dissolve sewage and excess fluids soak into the ground by means of a french drain √ Conservancy tank √ – Sewage stored in a tank and pumped out when nearing full capacity √ Pit toilet ANY OTHER ACCEPTABLE ANSWER (4) [30] Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 10 DBE/November 2012 NSC – Memorandum QUESTION 4: LO3 AS 2, 3, 7, 8 4.1 4.1.1 FALSE √ (1) 4.1.2 TRUE √ (1) 4.1.3 TRUE √ (1) 4.1.4 FALSE √ (1) 4.1.5 TRUE √ (1) 4.1.6 TRUE √ (1) 4.2 4.2.1 Submersion of wood – Absorbs more preservatives √ ANY OTHER ACCEPTABLE ANSWER (1) 4.2.2 Full cell process – Preservative process is faster √ ANY OTHER ACCEPTABLE ANSWER (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 11 DBE/November 2012 NSC – Memorandum 4.3 A B C D 1/ 6,0 m √ √ Area of wall before deductions √ 2,7 m √ 16,2 m² 6 000 mm x 2 700 mm (4) 1/ 1,2 m √ √ Area of window 1 √ 1,5 m 1,8 m² 1 200 mm x 1 500 mm (3) 1/ 1,2 m √ √ Area of window 2 √ 0,6 m 0,72 m² 1 200 mm x 600 mm (3) Total area of wall, excluding windows 16,2 m² - 1,8 m² - 0,72 m² = 13,68 m² √ (1) √ Number of bricks 1/ √ 13,68 m² 110 bricks for 1 m² of 220 mm wall (4) 110 √ 1 504,8 √ 1 505 bricks will be required 5% wastage and breakages 1 505 bricks x 5% 75 or 76 bricks Total number of bricks 1 505 bricks + 75 bricks √ or 1505 + 76 = 1 580 bricks √ = 1 581 bricks or 1 505 x 1,05 = 1 580,25 = 1 580 bricks or 1 581 bricks (2) 4.4 4.4.1 Breaking √ (1) 4.4.2 Angle iron √ (1) 4.4.3 Copper √ (1) 4.4.4 Galvanising √ (1) 4.4.5 Corrosive √ (1) [30] Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 12 DBE/November 2012 NSC – Memorandum QUESTION 5: LO3 AS 5, 6 5.1.1 8N √ (1) 5.1.2 20 N √ (1) 5.1.3 0N √ (1) 5.1.4 3 m √√ (2) 5.1.5 Upward forces = downward forces √ √ 22,5 N + 15,5 N = 10 N + 8 N + 20 N 38 N = 38 N (2) 5.1.6 2 mm = 1 N √ (1) 5.1.7 SFa = 22,5 N √ (1) √ √ 5.1.8 SFb = 22,5 N – 10 N = 12,5 N (Candidates must show steps) (2) 5.1.9 SFd = 22,5 N – 10 N – 8 N – 20 N √√ or 12,5 – 8 – 20 = -15,5 N = -15,5 N (2) 5.1.10 SFe = 22,5 N – 10 N – 8 N – 20 N + 15,5 N √√ or -15,5 N + 15,5 =0N = 0N (2) 5.1.11 Yes √ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 13 DBE/November 2012 NSC – Memorandum 5.2 5.2.1 Area of figure A1 = ½bxh = ½ x 60 x 60 = 30 x 60 = 1 800 mm² Area of figure A2 = lxb = 60 x 60 = 3 600 mm² Total Area = 1 800 mm² + 3 600 mm² = 5 400 mm² Position of centroid from AB = (A1 x d) + (A2 x d) Total area √√ √√ √√ √√ = (1 800 x 80) + (3 600 x 30) mm3 5 400 mm² √ = 144 000 + 108 000 mm3 √ 5 400 mm² = 252 000 mm3 5 400 mm² = 46,67 √ mm √ OR Take moments about A on Y-axis √√ √√ √√ √√ 5 400 mm² x X = (1 800 x 80) + (3 600 x 30) mm3 5 400 mm² x X = 144 000 + 108 000 mm3 X = 252 000 mm3 √ 5 400 mm² √ = 46,67 √ mm √ OR Part AREA (A) X AREA OF X Ax Triangle 1 800 mm² √√ h = 60 = 20 + 60 = 80√√ 144 000 mm3 3 3 Square 3 600 mm² √√ S = 60 = 30 108 000 mm3 2 2 √√ Σ 5 400 mm² √ 252 000 mm3 √ Σ AX ΣA = 252 000 mm3 5 400 mm² (12) = 46,67√ mm √ 5.2.2 30√ mm √ (2) [30] Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 14 DBE/November 2012 NSC – Memorandum QUESTION 6: LO3 AS4, 5, 7, 8 ANSWER SHEET 6.1 QUESTION 6.1 Assessment Marks criteria Rafter 2 King post 1 Strut 2 Queen post 2 Tie beam 1 King post Neatness 2 √ √ Application of Rafter √ √ scale 3 Any two lables 2 √ Total 15 Strut √ √ Queen post √ √ √ Tie beam Copyright reserved Please turn over

Downloaded from hlayiso.com Civil Technology 15 DBE/November 2012 NSC – Memorandum ANSWER SHEET 6.2 QUESTION 6.2 √ √ √ √ 220 W1 W1 W1 √ W2 √ √ √ 3 000 √ OFFICE 110 D2 √ D2 √ √ √ √ Assessment Marks √ criteria STORE External walls 4 √ WORKSHOP ROOM √ 6 450 Internal walls 2 Windows 6 √ Doors 3 Roofline 4 WHB 1 √ √ Labelling 2 Any TWO 2 √ dimensions Neatness 1 D1 W1 W3 Total 25 √ √ 220 Door 1 can be a double door, sliding door or a roll up door FLOOR PLAN √ SCALE 1 : 100 √ NOT TO SCALE Copyright reserved