PROFIS Engineering Premium - Anchor Design [Part 3]

Creep issue of chemical fasteners is further emphasized in EC2-4 by a new sustained load factor

Another difference is on the creep behavior when it is under sustained loading. In ETAG, the sustained load test only indicates pass or fail with no consideration taken into calculation. In EC2, a reduction is adopted to cater the creep behavior. The factor considers the proportion between sustained load and total load, and the product performance under sustained load. Reduction factor is applied if the ratio of sustained actions in the design is higher product anticipated. 

Possible higher steel resistance in grouting situation

Another difference is the reduction factor in grouting situation. When there is a layer of grouting between base plate and base material, the gap will induce a lever arm in loading transfer. In both EC2 and ETAG design, reduction factor in shear resistance is applied according to the thickness of grout layer. However, the degree of reduction is different and EC2 is less conservative and allow a larger capacity for design.

Separate interaction for steel and concrete failure is now used

When combining tensile and shear strengths, only the lower strengths for each of the two types were considered in ETAG, even though the two strengths belonged to different breakages on the base material side - steel or concrete. This approach was very conservative. In the new Eurocode, it is indicated that the breakage of steel and concrete must be treated separately. This results in higher strength compared to ETAG, especially in seismic conditions.

Summary


Hereby is a brief summary on the difference between two codes. As in Hong Kong, both of the codes can be applied in the design and they are also support by our anchor design software – PROFIS Engineering.