Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Good construction practices - Part 2 - ACC

3,285 views

Published on

Best practices to achieve desired quality results in construction.

Published in: Real Estate
  • I would never forgive myself it i didn't give you one last opportunity to try the incredible Halki Diabetes Remedy for yourself! ★★★ http://t.cn/AiBhrKDq
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • I would never forgive myself it i didn't give you one last opportunity to try the incredible Halki Diabetes Remedy for yourself! ♣♣♣ https://tinyurl.com/y2956vb5
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Eat This POTENT Vegetable To Melt Diabetic Fat. IMPORTANT: Be careful, only eat it twice a day or you will lose diabetic belly fat too fast... ▲▲▲ https://bit.ly/2mBJACQ
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Good construction practices - Part 2 - ACC

  1. 1. Good Construction Practices – Part II This report is solely for the internal use. No part of it may be circulated, quoted, or reproduced for distribution outside the company organization without prior written approval from ACC Limited. This material was used during an oral presentation; it is not a complete record of the discussion.
  2. 2. Very necessary for strength and durability of concrete structure Do not start plastering before completion of Brickwork curing. Curing 2 ACC Limited 26.06.2010Good construction practices
  3. 3. By Hessian Clothes for columns & sides of beams Ponding on flat horizontal surface. Curing 3 ACC Limited 26.06.2010Good construction practices
  4. 4. Curing 4 ACC Limited 26.06.2010Good construction practices
  5. 5. 5 ACC Limited 26.06.2010Good construction practices
  6. 6. 6 ACC Limited 26.06.2010Good construction practices
  7. 7. Strength and Curing moist cured entire time in air after 3 days in air after 7 days Strength 100% 7 ACC Limited 26.06.2010Good construction practices time in air entire time in air after 3 days 28
  8. 8. All bricks should be of same size and color Bricks should be properly baked. If a brick is dropped from a height of 1 m, it should not break. How to choose Bricks? Brickwork Correct Practice: 8 ACC Limited 26.06.2010Good construction practices Bricks should be immersed in water at least two hours before use. Cement to sand proportion should be 1:5. Use the Mixed material within half n hour of mixing, otherwise it start loosing strength. Maximum 1 m work should be done in a day. All joints should be raked properly. Correct Practice:
  9. 9. Mortar and Plaster Even though mortar makes up as little as 7% of the total volume of a masonry wall, it plays a crucial role in the performance of the structure. It not only bonds the individual units together, but it also seals the building against moisture and air penetration. It can be used to bond to anchors, ties or reinforcing. 9 ACC Limited 26.06.2010Good construction practices The mortar is literally the glue that holds the wall system together. The primary ingredient in mortar is Portland cement. Since Portland cement is also used in concrete, we need to make a few distinctions here.
  10. 10. Mortar Concrete is formulated to become a solid monolithic wall system by itself. The most important characteristic of concrete is compressive strength. Mortar, on the other hand, is formulated to bind masonry 10 ACC Limited 26.06.2010Good construction practices Mortar, on the other hand, is formulated to bind masonry units together. There are several properties of mortar that can influence bond strength and durability. The most important qualities of mortar are bond strength and durability.
  11. 11. Requirements of mortar The single most important property of mortar is bond strength,. It is critical that this bond be complete, strong, and durable. The mechanical bond between individual bricks, blocks, or stones unifies the wall as a system, provides resistance to tensile stress, and seals against the penetration of 11 ACC Limited 26.06.2010Good construction practices tensile stress, and seals against the penetration of moisture.
  12. 12. Factors affecting mortar properties The strength and extent of the bond are affected by many variables of material and workmanship. Complete and intimate contact between the mortar and the unit is essential, Workability influences the ease with which the mortar spreads and covers the surfaces. 12 ACC Limited 26.06.2010Good construction practices spreads and covers the surfaces. Rough units have a very porous surface that is highly receptive to the wet mortar and increases adhesion
  13. 13. Factors affecting mortar properties The moisture content and suction of the units, the water retention of the mortar. Curing conditions such as temperature, relative humidity, and wind combine to influence the completeness and integrity of the mechanical and chemical bond. 13 ACC Limited 26.06.2010Good construction practices Voids at the mortar-to-unit interface offer little resistance to water infiltration and facilitate subsequent disintegration In aligning the masonry, laboratory tests show that tapping the unit to level will increase bond strength 50 to 100% over hand pressure alone
  14. 14. Factors affecting mortar properties Often overlooked is the size/shape of mortar joints in that the ultimate compressive load capacity of a typical 3/8 in. bed joint will probably be well over twice the value obtained when the mortar is tested as a 2 in. (50.8 mm) cube. Mortars should typically be weaker than the masonry 14 ACC Limited 26.06.2010Good construction practices Mortars should typically be weaker than the masonry units, so that any cracks will occur in the mortar joints where they can more easily be repaired.
  15. 15. Factors affecting mortar properties Compressive strength of mortar increases with an increase in cement content and decreases with an increase lime, sand, water or air content. Retempering is associated with a decrease in mortar compressive strength. The amount of the reduction increases with water addition and time between mixing and retempering. 15 ACC Limited 26.06.2010Good construction practices and time between mixing and retempering. It is frequently desirable to sacrifice some compressive strength of the mortar in favor of improved bond, consequently retempering within reasonable time limits is recommended to improve bond.
  16. 16. RCC Band at 1 m height which should be of 4 ‘ thick with two bars of minimum 8 mm 16 ACC Limited 26.06.2010Good construction practices Avoid corner windows in Load bearing structures
  17. 17. 17 ACC Limited 26.06.2010Good construction practices
  18. 18. 18 ACC Limited 26.06.2010Good construction practices
  19. 19. Surface Preparation Before plastering concrete surface should be hacked properly ( Minimum 50 per sq.ft.) It is advisable to apply a base coat of cement paste on concrete surface, and cure it for three days to have a better bonding . 19 ACC Limited 26.06.2010Good construction practices days to have a better bonding . A brick wall should be made wet a day before plastering
  20. 20. The surface to be plastered should be accurately positioned overall and zones should not deviate excessively from a plane (or curved) surface. Ideally, the substrate should be rough; absorbent to a limited extent; strong; and clean, i.e. free of any film, such as dust, oil or paint, that could impair bond between plaster and substrate.. Roughness improves adhesion by providing a positive Surface Properties required 20 ACC Limited 26.06.2010Good construction practices Roughness improves adhesion by providing a positive “key” for plaster to grip. Absorption removes the water film, between substrate and plaster, that would tend to weaken adhesion. Excessive absorption will however dry out the The strength of the substrate material should be greater than, or equal to, that of the hardened plaster.
  21. 21. Surface Preparation Background surfaces should ideally be at least as rough as coarse sandpaper or rough-sawn timber. Surface roughness can be achieved in one of the following ways: Using formwork with a rough surface, 21 ACC Limited 26.06.2010Good construction practices Using formwork with a rough surface, Stripping formwork early and wire brushing concrete Hacking Abrasive blasting (e.g. sand blasting) Applying a spatter dash layer
  22. 22. Surface Preparation Spatter dash is a mixture of one part of cement to one and a half parts of coarse sand with enough water for sluggishly pourable consistence. The mixture is thrown forcibly on to the wall, using a scoop or a brush with long, stiff bristles. (The impact drives out the water film at the interface between spatterdash and substrate and hence improves adhesion.) 22 ACC Limited 26.06.2010Good construction practices The Spatterdash should cover the substrate surface completely and form a rough texture with nodules about5 mm high. Spatterdash must not be allowed to dry out for at least three days.
  23. 23. Absorption Assess absorptiveness by throwing about a cupful of water against the surface. The surface will fall into one of the three categories: No water is absorbed. Some water is absorbed but most runs off. Most of the water is absorbed. First type of surfaces, include hard-burnt clay face bricks, glazed bricks and very dense high-strength concrete, 23 ACC Limited 26.06.2010Good construction practices glazed bricks and very dense high-strength concrete, should be prepared by applying a spatter dash Second type of surfaces should not require any treatment to control suction. Third type of surfaces should be wetted thoroughly and then allowed to become surface dry before the plaster is applied.
  24. 24. Surface - Monolithic concrete. Provide a rough surface by using rough-textured formwork, early stripping of formwork and wire brushing the concrete, hacking or abrasive blasting. (If none of these is practicable, apply a spatter dash coat after ensuring that the surface is clean.) Ensure that no form-release oil is left on the surface to be 24 ACC Limited 26.06.2010Good construction practices Ensure that no form-release oil is left on the surface to be plastered. Clean down by water jetting or vacuuming. Conventional structural concrete should not require wetting to control suction. High-strength concrete may require the application of a spatter dash coat.
  25. 25. Surface - Brickwork Burnt clay brickwork If the surface is dusty, clean by brushing, water jetting Burnt clay stock bricks normally have a very high suction; pre-wet the wall and allow it to become surface dry before applying the plaster. Sun dried or poorly burnt soft clay brickwork This type of walling may be found in very old buildings, 25 ACC Limited 26.06.2010Good construction practices This type of walling may be found in very old buildings, usually when restoration or repairs are being done. Care should be taken when removing the old plaster so as not to damage the bricks. Protect the wall from rain water once the bricks are exposed. Rake out the joints about 10 mm deep (the mortar is normally very soft). Brush down the wall to remove any loosely adhering material. Lightly dampen the wall and apply a spatter dash coat that improve adhesion.
  26. 26. Very Smooth Surface Result in to Poor Bonding. 26 ACC Limited 26.06.2010Good construction practices Use Bonding agent Or Hack the surface at close spacing
  27. 27. Surface making…. 27 ACC Limited 26.06.2010Good construction practices
  28. 28. 28 ACC Limited 26.06.2010Good construction practices
  29. 29. 29 ACC Limited 26.06.2010Good construction practices
  30. 30. 30 ACC Limited 26.06.2010Good construction practices

×