The Swimming Pool, as the name suggests, is a man-made pool which holds water for the family to swim in. Swimming pools can be made with a variety of different materials depending on the application and location. A roof-top swimming pool, for example, looks better when one of its sides is made with Reinforced Glass or fibre Glass. Container tank swimming pools are also pretty common these days. These are swimming pools in which an old container is made water tight and then converted to a swimming pool. This construction technique makes the construction and relocation of swimming pool easier.
In all other cases where swimming pool is usually made on ground level, Concrete is the most preferred material – thanks to its durability, straight forward construction techniques, lower cost and easy availability. These kind of swimming pools last much longer than the other kinds and give a classic look which we have seen in movies.
The Concrete Swimming Pool is the most popular choice for in-ground pools. They initial costs are soon paid back with the longer life of the swimming pool Also, unlike other kinds of pools, concrete pools are serviceable and therefore can be repaired and even enlarged afterwards.
Concrete Swimming Pool Construction and Design
Concrete used in the construction of swimming pool has to be reinforced, usually with Grade 60 Steel. Reinforcement is required as he concrete experiences bending stresses produced from water – and soil, when constructed in-ground.
The greater the depth of water, the stronger the swimming pool walls need to be. A normal strength Concrete, M20 or higher grade would work fine for the swimming pool. Reinforcement and Concrete should be designed in detail prior to beginning construction of the swimming pool.
As it can be seen from the illustration of the masonry wall, greater strength is required in the bottom of the wall. The floor of swimming pool, on the other hand, experiences the same vertical pressure at every point and therefore requires the same reinforcement in every part of it.
If constructed in-ground, as already mentioned, Reinforced Concrete doesn’t only have to bear the loads of water but also of the surrounding soil. The reinforced wall acts as a retaining wall, retaining the load of soil at two different levels. The load of water and soil counteract each other as the loads of soil are distributed in the same manner as of water.
However, the swimming pool should be designed in a manner that it can resist the soil loads even when the pool is empty. An empty pool would lack the pressure from water that would help counteract the soil pressure.
Swimming Pool Design considerations
When designing a Swimming Pool which is only partially in-ground and extends above ground level, soil pressure is not considered for the part which is above the ground level. Only, water pressure is considered for that part of the design.
The design of such Reinforced Concrete walls is always based on standard regulations which define the minimum strength of Concrete and Steel which should be used for the construction – M20 Concrete and Grade 60 Steel with a minimum wall thickness of 6 inches are American Concrete Institute (ACI) Requirements for example.
The reinforcement can be steel or any other material such as CFRP (Carbon Fiber Reinforced Polymer) or GFRP (Glass Fiber Reinforced Polymer). These Polymer based Reinforcement types usually have higher tensile strength and make Reinforced Concrete a relatively ductile material. They are usually expensive than Steel but since these reinforcement types are stronger, a lower amount would be used.
Concrete Swimming Pool Construction
- Selection of Land and Design
This includes the architectural as well as structural design. The depth of Pool affects the amount of steel and the thickness of concrete wall.
- Excavation of Earth
- Compaction of Soil
- Construction of Swimming Pool Base
A lean concrete base is provided before the actual construction of floor. This should be done at a gradient so that the emptying of swimming pool would be easier at later stages.
- Steel Cage placement
- Pump and Filter System Placement
- Concreting – This can be done using Shotcrete technique or formwork. Shotcrete eliminates the chances of gaps.
- Waterproofing of Concrete – This can be done using Tiles, Glass, Ceramic or Epoxy or any other water-proofing method.
- Coping Construction.
There are a number of questions that usually arise when one talks about Reinforced Concrete Swimming Pools. Some of the frequently asked questions are answered below.
Do concrete pools need waterproofing?
If Concrete, is not sealed properly, it would leak water to the surrounding soil. This causes problems as the soil in the surrounding would get wet. The soil would exert a higher pressure since water and soil would act together now.
This also poses the risk of uplift water pressure.
Piping and Soil erosion is also possible which would leave a hollow space in the underlying soil and therefore it wouldn’t be able to bear the loads and would have chances of collapse.
How long do concrete pools last?
It usually depends on the conditions it is exposed to. A structural designer mentions the service life of the structure he designs. On average, the Reinforced Concrete Pools survive 40-60 years. Salt water Pools survive shorter than Fresh Water Pools since Salt intrusion in Concrete causes some complications.
What type of Concrete is used for Swimming Pools?
Conventional Concrete can be used for the construction of the pool. Usually M20 Grade concrete or higher can suffice the structural needs. However, it is preferable to use to water proofing admixtures in the concrete.
The resulting concrete would have lesser or almost zero infiltration of water and consequently, a longer service life.
Are Concrete Pools Better?
It actually depends requirements and location of the pool. But in general, Reinforced Concrete Swimming Pools are cheaper and easier to construct.
If necessary later in life, the repairing of Reinforced Concrete Swimming Pools is much easier as compared to other materials like fibreglass pools.
Design of Swimming Pools using 3D CAD.
By designing the swimming pool using 3D CAD all of the material thickness and strength requirements can be checked prior to the pool construction starting. Additionally, the pool can be viewed from any angle to ensure the privacy and aesthetic design goals are met from any possible viewing angle. This is a great design tool when designing an integrated landscaping and swimming pool package. The 3D swimming pool and landscaping fly-through is a great way for the customer to visualise the finished product before pool design sign-off.
Related landscaping ideas from Red’s Landscaping Melbourne.
More information about Pools