Pipes with external concrete weight coating are designed for construction, repair and upgrading of submerged crossing of pipelines, crossing through swampland, pipe laying at watered and offshore areas.
External Concrete Weight Coating (hereinafter – CWC) is applied by “impingement” method with concrete mix, made of natural aggregates. All aggregates used for CWC production process have appropriate certificates on suitability of application; the mixture passed a range of testing in certified laboratories.
Concrete mixture preparation is carried out at stationary batch plant “ELKOMIX-135”, integrated in production process. The whole process of concrete mix preparation is fully automated due to computer-based control system. Homogeneity of mixture is provided by automated control system for materials dosing, mixing, and application of concrete coating at appropriate station. Manufacturing, transportation, laying and impaction of concrete mixture as parts of production process are connected in one technological cycle.
High impaction rate of coating allows producing the concrete with reduced permeability and, as a result, with high corrosion resistance of coating against aggressive medium and the environment (sulfate, water, frost resistance, etc.). Low air entrainment (absence of voids) allows producing coating with high mechanical strength, uniformity, integrity and with increased crack resistance, provided by this method of application.
In production of concrete coating, an ultra-hard concrete mixture with unchanged, defined, low water-cement ratio is used, which affects rapid reaching of designed strength. An accelerated hardening of concrete coating can be carried out in curing chambers (reaching of designed strength for the first 24 hours of curing).
The concrete mixture has less hardening time (CWC strength in 1-2 days is 50.7 - 66.0 MPa).
Due to the impingement method of CWC application, defects of coating are easily detected (visual inspection), identified, measured and controlled.
|No.||Parameter||Unit of measurement||Values|
|1||Diameter range||mm||219 - 1420|
|2||Concrete coating thickness||kg/m3||1900 - 3400|
|3||Concrete coating thickness||mm||40-150|
|5||Production with metal cage||-||Yes|
|6||Production with reinforcing wire mesh||-||Yes|