Determination of the concrete cover according to the EHE 08 regulation (37.2.4).

• The concrete cover is the distance between the outer surface of the reinforcement (including fences and stirrups) and the nearest concrete surface.
  
  
• To ensure the minimum values​​, the regulation increases the minimum cover with a cover margin according to the kind of concrete control.
  
  
• According to regulations, "In the particular case of strongly aggressive atmosphere or special fire hazards, covers specified in this Article shall be increased."
  
  
• The minimum cover values ​​are contingent on a correct dosage of concrete for each exposure class. If experimental data of aggressiveness in similar structures nearby, or if more demanding covers than those at the regulation are required, you can check the actual durability following the Annex 9.
  
  
• For joists or precasted slabs at fixed industrial installation, designed to one-way slabs, it is possible to count with the added coatings while being compact, impervious and permanent nature. In these cases the actual cover will be greater than 15 mm.
  
  
• The cement types of the different classes are defined as indicated in the regulations. This program DOES NOT CHECK the consistency of choice of cement in each class, the user must make consistent selections of the types of cement.
  
  

Parameters:
Type of element:	.Precast with thorough inspectionElements in situ with thorough inspectionThin slabs (care execution)Other cases.
Element concreted against soil:	Yes
Active prestressed reinforcement:	Yes
General environment class:	.IIIaIIbIIIa IIIbIIIcIV.
Project useful lifetime =	.50100.	years
Specific classes:
Chemically aggressive	.-QaQbQc.
With frost:	.-HF.
Erosion:	.-E.
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Results:
Type of environment:	I			EHE-08, 8.2.1
Cover margin Δr=	10	mm		EHE-08, 37.2.4
Minimum covers:
For general class =	15	mm		EHE-08, 37.2.4.1, table 37.2.4.1.a
Minimum cover to consider rmin=	15	mm
Nominal cover rnom= (to be indicated in plans - separators)	25	mm		EHE-08, 37.2.4

• The cover margin proposed by te regulation aims to ensure the minimum cover on all points. In beams and slabs, the bottom cover is reduced due to the reinforcing bars bending between separators. Also it is intended to deal with the roughness of the concrete surfaces, and margins and tolerances in the concrete execution.
  
  

Version 13/08/2012