យើងខ្ញុំមានពិគ្រោះយោបល់ពីសសរគ្រឹះសំណង់អាគាររបស់លោកអ្នកដោយឥតគិតថ្លៃ។ ទំនាក់ទំនង់៖ ០២៣​ ៩៩៦ ៨៧៦/០៨៨ ៦៦ ៥៥ ៧៧៧/០៨៨៧ ៦៣៦ ៦៣៦។

FOUNDATION PILES

7FTD manufactures prestressed concrete foundation piles. The main standards that are used for the company’s products are structured below:

  • Standard for foundation piles:
    • Japanese standard JIS A 5335 – 1987: Prestressed centrifugal concrete pile
    • Japanese standard JIS A 5337 – 1995: Prestressed centrifugal concrete pile with high strength
    • TCVN (Vietnamese standard) 7888 – 2008: Prestressed centrifugal concrete pile

Besides the above mentioned product standards, many other standards have been applied and implemented in order to manufacture quality products. These standards deal for instance with material and construction issues.

The prestressed foundation piles are manufactured in the 7FTD factory following the Japanese standard JIS. This Japanese Industrial Standard specifies the centrifugally spun prestressed high strength concrete piles which have been manufactured by pretensioning to make compressive strength. PHC piles shall be classified into classes A, B and C according to the effective prestress.

Technical characteristics of PC-piles and PHC-piles will be described in table 1 and 2.

Table 1: PC piles following JIS-standard
  • Concrete strength at 28 days is 60MPa=60N/mm2=600kgf/cm2
  • Cracking moment needs to meet the standard: JIS A 5335-1987

Besides the products mentioned in table 1, there are more possibilities depending on the customer’s design.

Table 2: PHC piles following JIS standard
  • Concrete strength at 28 days is 78.5MPa=78.5N/mm2=785kgf/cm2
  • Cracking moment needs to meet the standard JIS A 5337 – 1995

Besides the products mentioned in table 2, there are more possibilities depending on the customer’s design.

ADVICE

Following the invention of prestressed high strength concrete piles by Japan in the early 70’s, PHC piles have been used widely in many well-developed countries. PHC piles have distinct advantage over the other techniques in the following aspects:

  • High loading capacity per pile
  • A wide range of applications
  • Adaptable to ground condition
  • Ease of transportation
  • Rapid construction, high efficiency and short construction period
    • Driving by hammering the pile into the soil
    • Static pressing
    • Using a bored hole in the ground
  • Easy to maintain a clean and tidy working environment
  • High strength, good penetration power
  • Reliable quality
  • Ease of inspection and testing
  • Adaptable to a wide range of installation methods

By comparing with bored piles, PHC piles are manufactured in a factory environment under a tight quality control process. In contrast, the concrete for bored piles is cast in-situ so it is always difficult to ensure that the concrete has been compacted and cured properly. It is obvious that the quality of bored piles is more human dependent and it is significantly more expensive to use bore piles than PHC piles in terms of construction cost for a specified total design load.

H-piles on the other hand are stronger than PHC piles in terms of strength, but its corrosion resistance is significantly inferior to PHC piles. They are also more expensive than PHC-piles.

The PHC-pile has a lot of virtue over the square concrete pile. It has a steady and credible quality, high concrete strength, strong transfixion ability, high bearing capability, and fine accommodation to different geologic conditions or different construction measures

The advantages of the PHC piles can be summarized as follows:

HIGH STRENGTH: Owing to the deliberative design of concrete mix proportion, the adoption of super plasticizer, centrifugal-forming and autoclave-curing, the compressive strength of PHC pile concrete is above 80.0MPa, the bearing capacity of pile is great and the piercing power is strong.

  • Excellent bending resistance: Owing to the high strength of pile concrete and the adoption of special high-strength low-relaxation steel bar, the effective prestress of this pile is rather great. Compared with other types of concrete piles, the PHC pile has a rather great flexural resistance, which can effectively restrain the pulling stress caused by driving.
  • Excellent durability: As a result of centrifugal-forming and autoclave-curing, high degree compaction and high strength concrete has been produced. the permeable and erosive resistance is favorable.
  • Easy in construction: The length of each pile can be made up by various sizes according to the demands of design. The type of welding joint and pile shoe can be chosen in accordance with the geologic conditions.
  • Quality stability and reliability:With the first-ranking equipment and technology, strict quality control and assurance system, the quality of products has been proved to be excellent and stable.
  • Reduced weight:Compared with other types of piles, the PHC pile has a greater bearing power. So the amount of piles can be reduced. The length, diameter and thickness of pile can be chosen according to the bearing capacity respectively. Compared with square piles, the cost of materials is reduced greatly. The construction period is shorten by using the pile. Hence, the comprehensive cost of PHC pile is Lowest.