INCREASE BONDING OF PLASTERING AND SCREEDING ON CONCRETE SUBSTRATES

Problem

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CONCRETE WALLS AND COLUMNS

There are 2 types of concrete walls and columns 1. Pre-cast concrete 2. Cast in-situ concrete There are many points of concern when using pre-cast and cast in-situ concrete walls and columns including horizontal alignment,concrete surfaces that could be rough with air bubbles, and joints of concrete formworks.

Solution

Solutions for points of concern

1. Using concrete plaster
2. Using conventional plaster to replace concrete plaster
  • Using conventional plaster to replace concrete plaster,which its cost is higher, but textures are needed to give bonding between conventional plaster and concrete substrates.

How to make texture on concrete substrates

1. Material for making texture

Textures are mostly made from 3 types of material

  1. Sand and cement
  2. Concrete plaster
  3. Tile adhesive
2. Mix the material with water and then splash or spread the mixture onto concrete substrates to create the texture.
3. Splash the mixture onto concrete substrates by using appropriate tool such as stiff typebroom
4. Using notched trowel to spread the mixture of tile adhesive
5. Leave the texture to dry completely for one day and then rending over with conventional plaster.

Probable problems from using conventional plaster with texture on concrete substrates

  • Insufficient bonding between conventional plaster and concrete surface leading to cracks and flaking off when there are not enough textures
  • Waste of waiting time for the texture to set for at least one day before being able to render over
  • Variety types of material to create the texture making it's hard to obtain constant quality

REVOLUTION OF CONCRETE PLASTERING

REVOLUTION OF CONCRETE PLASTERING BY USING  weberprim concrete

  • Give bonding between conventional plaster and concretesubstrate, without the use of expensive concrete plaster
  • Replace textures
  • 5 times saving*
  • Reduce complicated steps of rendering on concrete walls andcolumns
  • Material and labor costs saving
  • Easy to use, fast and convenient

Comparison of plastering works on concrete substrate

Bond to concrete

The result of weberprim concrete being tested its bond-to-concrete property

  • weberprim concrete provides a high bonding to concrete of 0.58 N/mm2
  • When the method using textures provides only 0.3 N/mm2 and concrete plaster provides 0.40 N/mm2

This shows weberprim concrete giving higher and better bonding than textures creating and concrete plaster to concrete substrates.

Plastering expenses

Plastering expenses
  • 5 times saving when using weberprim concrete to replace the method of textures creating
  • The expense of applying textures and then using ordinary plaster is higher than using weberprim concrete primer at 45 Baht/m2 (194 - 149 = 45 Baht)
  • The expense of using concrete plaster is higher than using weberprim concrete primer at 48 B/m2 (197 - 149 = 48 Baht)

* Using weberprim concrete to prepare the substrate is saver than applying textures to 5 times = 77/15 by average

Expenses for plastering work is calculated at 2 cm. thickness

Comparison between applying textures and weberprim concrete

ROUGH SURFACE OR TEXTURE CREATING

weberprim concrete

1. Many ingredients causing difficulty to control quality of mixingprocess by the workmen

1. Only weber.prim concrete mixing with specific amount of waterproviding constant quality

2. Inconstant and discontinuous textures possibly causing plasterlayer to de-bond 2. Increase plaster bonding by easily applying by brush or roller
3. Complicated mixing and working process 3. Easy and convenient to use
4. 24-hour waiting time before plastering over 4. Faster plastering; only 20-minute waiting time
5. High cost of labor and material 5. 5-time saver of labor and material costs*
6. High labor skill is required for plastering continuity 6. Not complicated, can be simply applied by any labors

(*) Cost of labor and material comparison between texture method and application of weberprim concrete

weberprim concrete: to increase bonding of plastering and screeding on concrete substrates

  • Wall : to increase bonding with concrete substrate only using conventional plaster.
  • Floor: to increase bonding of new topping/leveling mortar, terrazzo,and exposed aggregate finish on existing concrete floor.