Concrete Technology. Soil and Asphalt Compaction. Basics. Utility. Demolition. WNA/TCE - ws. Reference (apr02)

Transcription

1 Concrete Technology Utility Basics Soil and Asphalt Compaction Demolition 6

2 Internal and external vibrators, inverters, trowels, wet screeds, rebar cutters 7

3 What is concrete? Concrete Components Hydration a man-made (artificial) stone a mixture of cement, aggregates and water and often admixtures (retardants, accelerators, plasticizers, etc.) Concrete solidifies and hardens after mixing with water due to a chemical process known as hydration. The water reacts with the cement, which bonds the other components together, eventually creating a stone-like material. Reinforcement Reinforced concrete is concrete in which steel reinforcement bars ( rebars") or fibers have been embedded to strengthen a material that would otherwise not stand the tensile strengths. 8

4 Why does concrete need to be vibrated? Freshly placed, uncompacted concrete is usually full of entrapped air bubbles. Concrete will only achieve a high compressive strength and density with minimum air content through the use of mechanical means, i. e. the introduction of highfrequency (fast, repetitive) vibrations. Only in this way can concrete meet today s requirements in terms of strength and density. 9

5 Why does concrete need to be vibrated? 10

6 What actually happens during concrete vibration? The high-frequency vibrations generated by the vibrator are transmitted to the components of the fresh concrete. Frictional forces between individual particles are substantially reduced. A flow process is created. Air bubbles, excess water and paste entrapped through capillary action and surface tensions are released and escape to the surface. 11

7 Advantages of concrete vibration Greater density and homogeneity Greater compressive strength Greater durability (e. g. de-icing salt) Better bond with rebar, particularly in densely reinforced sections Better bond between the individually wet on wet placed layers Improved quality exposed (fair-faced) surfaces Makes possible use of drier mixtures, thus requiring less cement 12

8 Concrete vibration: tips and tricks 10 x Know your effective compaction diameter: For practical purposes and as rule of thumb consider the operating diameter to be approx. 10 times the vibrator head housing diameter. 13

9 Maintain correct spacing when compacting large surfaces correct wrong formwork 14

10 Correct spacing when vibrating fresh concrete in walls Internal vibrators with Ø 30 (1.2 ), 38 (1 ½ ) and 45 mm (1.8 ) should not be used due to poor or non-existing overlapping of the effective compaction Ø. This will lead to a faulty or uneconomical vibration process cm 15

11 Correct spacing when vibrating fresh concrete in walls For greater effective compaction Ø and for more convenient, economical compaction (less insertions, less time) preferably use only vibrators with diameters 57 or 65 mm, provided the rebar allows it. The concrete will be compacted faultlessly thanks to the overlapping cm 16

12 Layer depths when vibrating fresh concrete Practical experience has shown that evenly and horizontally spread layers of approx. 50 cm (20 ) thickness provide the best results in concrete compaction. 17

13 Concrete Technology Utility Internal vibrators Soil and Asphalt Compaction Demolition 18

14 Concrete vibrating equipment: Internal vibrators High frequency IRFU IREN IRSEN IRSEN-FU Ø 30, 38, 45, 57k, mm Ø 30, 38, 45, 57k, mm Ø 30, 38, 45, 57k + 57 mm Ø 38, mm 19

15 Concrete vibrating equipment: Internal vibrators High frequency internal vibrators advantages IRFU Ø 30, 38, 45, 57k, mm IREN Ø 30, 38, 45, 57k, mm High, constant compaction performance Practical handling Long-lasting design Nearly maintenance-free Protective hose with extra lengths Low weight Wide product range 20

16 Concrete vibrating equipment: Internal vibrators Compressed air PIR Modular system HMS For occasional concrete applications Excellent compaction performance Needs a compressor to operate Problematic operation during winter season Ø 35, mm Flexible through modular design Attractive pricing High flexible shaft wear Uncomfortable handling due to rigidity of flex shaft High manpower costs Ø 25, 35, 45, 50, mm 21

17 Concrete Technology Utility External vibrators Soil and Asphalt Compaction Demolition 22

18 Concrete vibrating equipment: External vibrators External vibrators usually are firmly attached to the formwork in precast concrete factories or on job sites The compacting energy generated by eccentric weights is transmitted from the vibrator through the formwork into the concrete. 23

19 Concrete vibrating equipment: External vibrators Application areas typically in precast concrete factories repetitive elements, such as prefab columns, walls, beams, etc. 24

20 Concrete vibrating equipment: External vibrators Application areas and on job sites for elements with complicated designs such as e.g. slanted surfaces very narrow elements elements with very narrowly placed rebar elements with large openings 25

21 Concrete vibrating equipment: External vibrators 26

22 Concrete vibrating equipment: External vibrators 27

23 Concrete vibrating equipment: External vibrators 28

24 Concrete vibrating equipment: External vibrators Application areas modern applications with fair-faced quality surface finish where a high quality of the surface is demanded where no pockets with fines or air allowed where consistent, fine-grained surfaces required where individual layers should not be discernible 29

25 Concrete vibrating equipment: External vibrators 30

26 Concrete vibrating equipment: External vibrators 31

27 Concrete vibrating equipment: External vibrators ARFU 36 flexible for individual applications 32

28 Concrete vibrating equipment: External vibrators Hungary Köröshegy bridge, the longest interurban bridge in Central Europe 33

29 Concrete vibrating equipment: External vibrators AR 36 flexible for individual applications, here Rental 34

30 Concrete Technology Utility Converters and inverters Soil and Asphalt Compaction Demolition 35

31 Concrete vibrating equipment: Converters and inverters 1938 Wacker is the first company in the world to patent and introduce 65 V safety voltage for internal and later external vibrators 36

32 Concrete vibrating equipment: Converters and inverters 37

33 Concrete vibrating equipment: Converters and inverters Mechanical converters FU series, e.g. FU 4/200 -> 3,8 kva from 20,6 to 69 A, 42 V, 200 Hz output Inverters (electronic converters) * FUE series, e.g. FUE 5/042/200 -> 3,8 kva from 6 to 145 A, 42 or 250 V, 200 Hz output * available for all standard international input voltages and frequencies 38

34 Concrete Technology Utility Trowels Soil and Asphalt Compaction Demolition 39

35 Strike-off, floating and surface troweling equipment: Trowels Surface quality, hard and flat 40

36 Strike-off, floating and surface troweling equipment: Trowels First phase 1: Wet surface Direction of rotation Blade arm Blades or floating pan (blade end) Blade angle= 0 Last phase: Plastic to hard Direction of rotation Blade arm Combination or finishing blades (blade end) Blade angle=

37 Strike-off, floating and surface troweling equipment: Trowels 42

38 Strike-off, floating and surface troweling equipment: Trowels 43

39 Strike-off, floating and surface troweling equipment: Trowels 44

40 Strike-off, floating and surface troweling equipment: Trowels Hand-held trowels CT Ride-on trowels CRT Edging trowels CT Troweling Ø - 36 and 48 (915 mm mm) Drives: - Honda 4-cylce engine - Wacker 4-cycle engine - Electric drive Handles - 6 versions Troweling Ø - 2 x 36, 2 x 48 (2 x 915 mm, 2 x 1220 mm) Drives - Honda 4-cycle engine - Wacker 4-cycle engine - B & S Vanguard 4-cycle engine - Lombardini diesel Wheel set - integrated in CRT 36 Troweling Ø - 24 (610 mm) Drives: - Honda 4-cylce engine - Electric drive Handles - 1 version 45

41 Concrete Technology Utility Wet screeds Soil and Asphalt Compaction Demolition 46

42 Spreading, screeding and surface compacting equipment: Wet screed 47

43 Spreading, screeding and surface compacting equipment: Wet screed 48

44 Spreading, screeding and surface compacting equipment: Wet screed Wet screed P 35 Blade lengths - 1,2 1,5 1,8 2,0 2,4 3,0 3,7 4,3 4,9 Drives - Honda 4-cycle gasoline engine Centrifugal force - 7 settings 49

45 Concrete Technology Utility Rebar cutters Soil and Asphalt Compaction Demolition 50

46 On site rebar cutting and bending: Rebar cutters 51

47 On site rebar cutting and bending: Rebar cutters 52

48 On site rebar cutting and bending: Rebar cutters Rebar cutters RCE 16/230 20/230 25/230 * Attractive, competitive price Fixed handle Only shearing head Pressure relief valve can only be opened with separate tool (Allen key) Low operating weight High cutting performance Cutting Ø: mm RCP 12/230-16/230 20/230 25/230 32/230 * Patented features: Interchangeable head mechanism Various handles Complete product range for almost all the usual rebar diameters Relief valve can be opened without tools (lever) High cutting performance Cutting Ø: mm 53

49 Concrete Technology Utility Rebar tying machine Soil and Asphalt Compaction Demolition 54

50 On site rebar tie-down: Rebar tying machine Rebar tying machine DF-16 for the quick and ergonomic tying of reinforcing steel bars (rebar) on the job site. The purpose of the tie-down is to develop a stiff skeleton, a so-called reinforcing cage. Tie-down performance up to: Min. outside diameter: Max. outside diameter: 1000 knots/h mm mm Min. clearance reinforcement : mm Tie wires per wire strip: 77 55

51 On site rebar tie-down: Rebar tying machine Rebar tying machine DF-16 for the quick and ergonomic tying of reinforcing steel bars (rebar) on the job site. The purpose of the tie-down is to develop a stiff skeleton, a so-called reinforcing cage. Dimensions: Weight: 720 x 60 x 85 mm 2,2 kg 56

52 On site rebar tie-down: Rebar tying machine 57

53 On site rebar tie-down: Rebar tying machine 58

54 On site rebar tie-down: Rebar tying machine Tie-down procedure Work sequence Load tie wire Position Push Pull Finished knot Bending Clearance under rebar: min mm 59 Always position unit vertically