Construction methods that should be avoided

The bad methods of construction and labor are major failures of buildings and structures.

1.- the wrong placement of the steel
It can lead to insufficient coverage, leading to corrosion of the armor. If the bars are badly placed out of position or in the wrong position, collapse can occur when the element is fully loaded.

2.- The incorrect reinforcement cover
Allows the entry of moisture, gases, other substances and leads to corrosion of the reinforcement, cracking and detachment of the concrete.
 

3.- The wrongly made construction joints
The lack of preparation and the bad compaction. Old concrete must be washed and a layer of rich concrete prepared before pouring is continued. Poor joints allow moisture to enter and stain the face of the concrete.

4.- The leakage of grout
It occurs in formwork joints that do not fit properly. The result is a porous area of ​​concrete that has little or no cement and fine aggregate.

5.- Poor Compaction
If the concrete is not compacted correctly by impact or vibration the result is a porous honeycomb portion of concrete. This part should be cut and stretched again. Complete compaction is essential to give a dense and impermeable concrete.


6.- Segregation
Segregation is generated when the ingredients of the mixture are separated. Is due to:
• Allow the mixture to come down from too high a height in the installation (gutters or pipes should be used in such cases).
• Use a hard mix with high coarse content.
• Large aggregate sinking due to over-vibration or overuse of plasticizer.
 


Results of unequal segregation in a concrete or porous concrete texture in some cases.

7.- Poor Cure
It results in the loss of water by evaporation. This can cause a reduction in strength if there is not enough water for complete hydration of the cement. Water loss can cause cracking by shrinkage. During curing the concrete should be kept moist and covered.

8.- Too much water content
Excess water increases the workability, but decreases the resistance, increases the porosity and the permeability of the hardened concrete, which can lead to the corrosion of the reinforcement. The correct proportion of water for the cement of the mixture must be strictly applied.