Bonded Post Tensioning - Evehx
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Bonded Post Tensioning


EVEHX is prepared to offer the most advanced in bonded Post Tensioning for works such as bridges, viaducts and large spans, which require a higher load.

In this modality, the cable is isolated from the concrete thorugh a metal sheath. After the post tensioning, it is necessary to inject cement cream for the complete filling of the sheath and the reestablishment of the adhesion to the concrete / steel.

The wire ropes divide space inside a same sheath and of a single multichipal anchorage. Usually, they are also stretched by a single large jack.

The injection cream guarantees the protection of the post-tension armors against corrosion and its concrete connections, through the sheaths. For the trace of the injection cream, each case must be studied taking into account the conditions of the materials and the structure type.

Components of the injection

  • Cement: Use Portlands CPI 25/32/40, CPII F 25/32/40 and CPII E 25/32/40 cements, meeting NBR.
  • Water and ice: Use potable water with chlorine content less than 500 mg / liter and free of detergents. In case of high temperature, ice should be used.
  • Additives: Using plasticizers, retardants and expanders. In each case, one should study the use of additives.

Injection Testing

The main tests required to verify the ideal traceability for cement injection mold (NBR 7681) are: fluidity (NBR 7682), exudation (NBR 7683), expansion (NBR 7683), compressive strength (NBR 7684) (NBR 7685). Consult the calculating engineer to find out about other tests.