Difference (Gabions Retaining walls & Reinforced Cement Concrete wall)
It can be differentiated on the basis of following parameters
1. Flexibility:
Gabion: Being highly flexible structure due to its double twists hexagonal mesh, it is not immediately affected by occurrence of any type of settlement in foundation strata, hence suitable for yielding foundation.
Reinforced Cement Concrete: Being rigid construction any settlement of foundation leads to development of cracks and hence suitable only for non-yielding foundation.
2. Permeability:
Gabions: High percentage of voids (30%) makes the structure highly permeable hence no
water pressure develops. There is also no uplift pressure, making structure more
stable. Their ability to combine drainage and retention functions makes them ideal
retaining structures.
Reinforced Cement Concrete: Weep holes provided in structures tend to clog. Subsequently, water pressure develops at the rear of the wall, thereby rendering the structure unstable.
3. Overhead Expenses:
Gabions: Since only stones/rubble is the only fill material required, hence the excess material from rock cutting can be used instead of disposing it in to the valley. Also this doesn't require any stone crusher or batching plant thereby
reducing the overhead expenses.
Reinforced Cement Concrete: Concrete being a mixture of aggregates and cement, the excess material from rock cutting has to be processed through a crusher and batching plant, thereby increasing the overhead expenses.
4. Noise Absorbent:
Gabions: Behavior Porosity of the structure absorbs the sound to a great level (18 – 30 decibels)hence reducing the sound pollution,ensuring environmental friendly
approach.
Reinforced Cement Concrete: Being rigid it does not help in absorbing sounds. The structure reflects sound waves, which may lead to sound pollution.
5. Environmental Friendliness:
Gabions: Structure is eco-friendly. Over a period of time natural cementation takes place in the structure, helping grass & plants to grow on & giving it natural beauty
along with making structure more stable, due to reinforcement with the plant
roots.
Cement concrete construction has proved to be a largely non-eco friendly
technology. Growth of vegetation leads to cracks thereby making the structure
more unstable.
6. Cost Effectiveness:
Gabions: Cost savings by using this solution is of the order ranging from
30% to 50%, since less time is required for execution.
As the work involves cost of cement, aggregates, steel, shuttering, mixers,
vibrators, water etc, it becomes more expensive.