Here follows information from various sources regarding Exposure classes used in StruSoft PRE-Stress and StruSoft Frame Analysis

Environmental classes

 The Danish annex defines environmental classes instead of exposure clases.

	Environmental class	Passive	Moderate	Aggressive	Extra aggressive
Country	1)
		X0	XC2	XD1	XD2
		XC1	XC3	XS1	XD3
			XC4	XS2	XS3
			XF1	XF2	XF4
			XA1	XF3	XA3
				XA2

¹⁾: DS/EN 1992-1-1 DK NA:2017

Maximum w/c ratio and Minimum concrete strength

 The British annex gives different maximum w/c-ratios and minimum concrete strengths depending on the concrete cover that is chosen. That is why several w/c-values and strength classes are shown in the table below. For some exposure classes the values even depends on the cement type in the concrete.

The table below is wider than the screen. Press (and release) middle mouse button to scroll sideways in the table

	Exposure class	Description	Maximum w/c-ratio				Minimum strength class
Country			1)	1)	1)		2)	1)
Life class					L50	L100		L50	L100
	X0	No risk of corrosion attack	-	-	-	-	C12/15	-	-
	XC1	Carbonation-induced corrosion	0.65	0.90	0.70	0.70	C20/25	C20/25	C20/25
	XC2	Carbonation-induced corrosion	0.60	0.60	0.65	0.65	C25/30	C25/30	C25/30
	XC3	Carbonation-induced corrosion	0.55	0.55	0.65 - 0.45	0.60 - 0.45	C30/37	C25/30 - C40/50	C28/35 - C40/50
	XC4	Carbonation-induced corrosion	0.50	0.55	0.65 - 0.45	No value given	C30/37	C25/30 - C40/50	No value given
	XD1	Chloride-induced corrosion (De-icing salt)	0.55	0.45	0.60 - 0.45	No value given	C30/37	C28/35 - C40/50	No value given
	XD2	Chloride-induced corrosion (De-icing salt)	0.55	0.45	0.55 - 0.40	No value given	C30/37	C20/25 - C40/50	No value given
	XD3	Chloride-induced corrosion (De-icing salt)	0.45	0.40	0.50 - 0.35	No value given	C35/45	C25/30 - C45/55	No value given
	XS1	Chloride-induced corrosion (Sea water)	0.50	0.45	0.55 - 0.35	No value given	C30/37	C25/30 - C50/60	No value given
	XS2	Chloride-induced corrosion (Sea water)	0.45	0.45	0.55 - 0.40	No value given	C35/45	C20/25 - C40/50	No value given
	XS3	Chloride-induced corrosion (Sea water)	0.45	0.40	0.50 - 0.35	No value given	C35/45	C25/30 - C45/55	No value given
	XF1	Freeze/Thaw attack	0.55	0.60	No value given		C30/37	No value given
	XF2	Freeze/Thaw attack	0.55	0.45	No value given		C25/30	No value given
	XF3	Freeze/Thaw attack	0.50	0.55	No value given		C30/37	No value given
	XF4	Freeze/Thaw attack	0.45	0.45	No value given		No value given	No value given
	XA1	Aggressive chemical environments	0.55	0.50	No value given		C30/37	No value given
	XA2	Aggressive chemical environments	0.50	0.45	No value given		C30/37	No value given
	XA3	Aggressive chemical environments	0.45	0.40	No value given		C35/45	No value given

  ¹⁾: EN 206:2013+A1:2016, Annex F, Table F.1

  ²⁾: EN 1992-1-1:2004, Annex E, Table E.1N

 ¹⁾: SS 13 70 03:2002

 ¹⁾: NA to BS EN 1992-1-1:2004, Table NA.2 and Table NA.3

Accepted crack width

For exposure class XF no values are given since they are to be combined with any other exposure class.

 EuroCode uses a special criteria for prestressing tendons called "Decompression". 

PRE-Stress assumes XD3 are part of this group too, since it is missing from the table. The condition of the prestressing wires are either OK and well within concrete in compression or placed in concrete in tension, or close to it (and in that case in need of a modification if the exposure class and load combinations so require). Then it will give a warning about strands in tension and a code reference. If it gives a warning the user has to check if it is ok or not to have the strands in a region with tension in the concrete or close to the tension zone. For decompression checks PRE-Stress will give an indication if the prestressing strand is in need of a compression check or not. It is not part of any utilization check, so the element might pass the utilization check even if there is a decompression check.

 The Danish annex is very straight forward when it comes to crack widths.

 The Norwegian annex says that XD3 should be included with same parameters as XD1, XD2, XS1, XS2 and XS3.

 In the Swedish annex, no values are given for XA-classes. 

PRE-Stress and Frame Analysis uses 0.30 and 0.20 by default.

The table below is wider than the screen. Press (and release) middle mouse button to scroll sideways in the table

	Exposure class	Description	Accepted crack width wk [mm]
Country			3)		1)			1)			2)
			Reinforcement and post tension cables (Quasi-permanent)	Prestressing tendons (Frequent)	Environmental class	Reinforcement	Prestressing and post tensioned reinforcement		Reinforcement and post tension cables (Quasi-permanent)	Prestressing tendons (Frequent)		Corrosion sensitive			Corrosion resistant
											Life class →	L100	L50	L20	L100	L50	L20
	X0	No risk of corrosion attack	0.4	0.2	Passive	No value given		X0	0.4	0.2	X0	-	-	-	-	-	-
	XC1	Carbonation-induced corrosion	0.4	0.2	Passive	No value given		XC1	0.4	0.2	XC1	0.40	0.45	-	0.45	-	-
	XC2	Carbonation-induced corrosion	0.3	0.2	Moderate	0.4	0.3	XC2	0.3	0.2	XC2	0.30	0.40	0.45	0.40	0.45	-
	XC3	Carbonation-induced corrosion	0.3	0.2	Moderate	0.4	0.3	XC3	0.3	0.2	XC3	0.20	0.30	0.40	0.30	0.40	-
	XC4	Carbonation-induced corrosion	0.3	0.2	Moderate	0.4	0.3	XC4	0.3	0.2	XC4	0.20	0.30	0.40	0.30	0.40	-
	XD1	Chloride-induced corrosion (De-icing salt)	0.3	Decompression	Aggressive	0.3	0.2	XD1	0.3	Decompression	XD1	0.15	0.20	0.30	0.20	0.30	0.40
	XD2	Chloride-induced corrosion (De-icing salt)	0.3	Decompression	Extra aggressive	0.2	0.1	XD2	0.3	Decompression	XD2	0.15	0.20	0.30	0.20	0.30	0.40
	XD3	Chloride-induced corrosion (De-icing salt)	No value given 0.3	No value given,  Decompression	Extra aggressive	0.2	0.1	XD3	0.3	Decompression	XD3	0.10	0.15	0.20	0.15	0.20	0.30
	XS1	Chloride-induced corrosion (Sea water)	0.3	Decompression	Aggressive	0.3	0.2	XS1	0.3	Decompression	XS1	0.15	0.20	0.30	0.20	0.30	0.40
	XS2	Chloride-induced corrosion (Sea water)	0.3	Decompression	Aggressive	0.3	0.2	XS2	0.3	Decompression	XS2	0.15	0.20	0.30	0.20	0.30	0.40
	XS3	Chloride-induced corrosion (Sea water)	0.3	Decompression	Extra aggressive	0.2	0.1	XS3	0.3	Decompression	XS3	0.10	0.15	0.20	0.15	0.20	0.30
	XF1	Freeze/Thaw attack	No value given		Moderate	0.4	0.3	XF1	No value given		XF1	No value given
	XF2	Freeze/Thaw attack	No value given		Aggressive	0.3	0.2	XF2	No value given		XF2	No value given
	XF3	Freeze/Thaw attack	No value given		Aggressive	0.3	0.2	XF3	No value given		XF3	No value given
	XF4	Freeze/Thaw attack	No value given		Extra aggressive	0.2	0.1	XF4	No value given		XF4	No value given
	XA1	Aggressive chemical environments	No value given		Moderate	0.4	0.3	XA1	No value given		XA1	No value given, 0.30			No value given, 0.20
	XA2	Aggressive chemical environments	No value given		Aggressive	0.3	0.2	XA2	No value given		XA2	No value given, 0.30			No value given, 0.20
	XA3	Aggressive chemical environments	No value given		Extra aggressive	0.2	0.1	XA3	No value given		XA3	No value given, 0.30			No value given, 0.20

³⁾: EN 1992-1-1:2004, Table 7.1N

¹⁾: DS/EN 1992-1-1 DK NA:2017

¹⁾: NS-EN 1992-1-1:2004+A1:2014+NA:2018

²⁾: BFS 2019:1 (EKS 11)

Crack safety factor

 The crack safety factor is a unique factor used in the Swedish Annex (BFS 2019:1, EKS 11)

For exposure class XF no values are given since they are to be combined with any other exposure class.

	Exposure class	Description	Crack safety factor ζ [-]
Country			2)
Life class			L100	L50	L20
	X0	No risk of corrosion attack	0.9	0.9	0.9
	XC1	Carbonation-induced corrosion	0.9	0.9	0.9
	XC2	Carbonation-induced corrosion	1.0	0.9	0.9
	XC3	Carbonation-induced corrosion	1.2	1.0	1.0
	XC4	Carbonation-induced corrosion	1.2	1.0	1.0
	XD1	Chloride-induced corrosion (De-icing salt)	1.5	1.2	1.0
	XD2	Chloride-induced corrosion (De-icing salt)	1.5	1.2	1.0
	XD3	Chloride-induced corrosion (De-icing salt)	1.8	1.5	1.2
	XS1	Chloride-induced corrosion (Sea water)	1.5	1.2	1.0
	XS2	Chloride-induced corrosion (Sea water)	1.5	1.2	1.0
	XS3	Chloride-induced corrosion (Sea water)	1.8	1.5	1.2
	XF1	Freeze/Thaw attack	No value given
	XF2	Freeze/Thaw attack	No value given
	XF3	Freeze/Thaw attack	No value given
	XF4	Freeze/Thaw attack	No value given
	XA1	Aggressive chemical environments
	XA2	Aggressive chemical environments
	XA3	Aggressive chemical environments

  ²⁾: BFS 2019:1 (EKS 11)