Bad practices in concrete construction are a result of poor construction management at the site. Bad practices in concrete construction will not only result in poor quality of the constructed service but also make the safety of the construction into a great concern.
Good construction practice must be a strict system which has to followed by the working individuals on the construction site. The top-level management along with the work contractors and sub-contractors have to see that these practices are followed as required.
Below mentioned are some of the bad construction practices followed on the construction site which are observed practically.
Improper training, inadequate quality, and negligence is the major reason behind the poor workmanship and construction methods.
Poor construction method will specifically result in:
High water content to obtain high workability is a bad practice. Increase in water will increase the porosity and the permeability of the concrete that will result in the corrosion of the reinforcement. It will also reduce the basic strength of concrete.
The supervisors and site in charge have to enforce strictly in order to follow correct amount of water-cement -ratio.
This is an issue observed in the fresh state of the concrete mix. The main reason behind the segregation of the concrete is:
Improper Curing is an issue caused due to negligence of the workmen and site supervisors. Proper curing has an important role in the hydration of the cement particles in the concrete. Good hydration will enhance the properties of concrete and hence the performance and durability.
Loss of water is high if curing is not proper. This will later result in cracking and shrinkage issues in the concrete structure.
Remember in concrete, the less water during concrete mixing/concreting and more water after curing is desirable. However unfortunately the reverse happen on site.
The reinforcement must be placed accurately to obtain the desired performance of the structure. Incorrect placement of the steel reinforcement will result in inadequate cover that will increase the chances of corrosion in concrete. Wrong position of the reinforcement will result in building collapse when the structure is under complete service load. The bars have to placed all along the length as per drawing to achieve fixed/pinned joints and should be properly lapped and staggered.
Inadequate cover of concrete will result in attracting the moisture and hence result in penetration of the water. This will result in cracking, and spalling due to corrosion in concrete structure.
Construction joints should be placed with proper planning. The number of construction joints and the space of construction joint are planned and implemented. Inadequate spacing will restrict the expansion-contraction of the structure. This will result in cracks in the structure.
Improper Construction Joints will result in penetration of moisture, chemicals, gases and undesirable substances. The penetration of gases will result in corrosion of the reinforcement, concrete spalling and cracking.
Improper compaction is a result of poor workmanship and negligence. The poured concrete has to be rammed and compacted properly. Poor compaction will result in honeycombed concrete. Proper compaction will help in a dense, compact and impermeable concrete structure.
Poor formwork will result in concrete elements where line, level and plumb are missing. The structure will look ugly on that account, further due to inadequate props. The beams may sink which will result in permanent deflected shape. Similarly if not tight, the column, beam, etc. will bulge and elements will go out of shape. The inadequate propping or lack of cross bracing may result in slippage or breakage of props which may invites collapse of building i.e. slab part which is being concreted. Gaps in formwork will result in leakage of cement slurry which will not only result in poor strength of concrete but also honeycomb concrete.
One main bad practice followed in construction is not following safety precautions when working at heights.
The main issues observed are:
These are some of the undesirable practices that is observed in construction site:
Neenu S. K.