## Appendix A Eurocode 2
\begin{cases}1+\frac{1-RH/RH_{0}}{0.1b_{0}^{1/3}}&\text{for }\ f_{cm} \leq 35\text{ MPa},\\ 1+\left[\frac{1-RH/RH_{0}}{0.1b_{0}^{1/3}}\alpha_{1}\right]\alpha_{2}&\text{ for }\ f_{cm}\geq 35\text{ MPa}.\end{cases}  \tag{11}\]  
\[\beta(f_{cm})=\frac{16.8}{\sqrt{f_{cm}}}\qquad\beta(t_{0})=\frac{1}{0.1+t_{0} ^{0.2}} \tag{12}\]  
where \(f_{cm}\) is the mean compressive strength of concrete at the age of 28 days (MPa), \(f_{cm0}=10\) MPa, \(RH\) is the relative humidity of the ambient environment (%), \(RH_{0}=100\) (%), \(h=2A_{c}/u\) is the notational size of member (mm), where \(A_{c}\) is the cross-section and \(u\) is the perimeter of the member in contact with the atmosphere \(h_{0}=100\) mm. The development of creep with time is given by  
\[\beta_{c}(t-t_{0})=\left[\frac{(t-t_{0})}{\beta_{H}+(t-t_{0})}\right]^{0.3} \tag{13}\]  
with  
\[\beta_{H}= \begin{cases}1.5\left[1+(0.012 RH)^{18}\right]h_{0}+250\leq 1500& \text{for }\ f_{cm}\leq 35\text{ MPa},\\ 1.5\left[1+(0.012 RH)^{18}\right]h_{0}+250\alpha_{3}\leq 1500\alpha_{3}&\text{ for }\ f_{cm}\geq 35\text{ MPa}.\end{cases}  \tag{14}\]  
The coefficients \(\alpha 1/2/3\) are calculated as function of the strength as  
\[\alpha_{1}=\left[\frac{35}{f_{cm}}\right]^{0.7}\qquad\alpha_{2}=\left[\frac{3 5}{f_{cm}}\right]^{0.2}\qquad\alpha_{3}=\left[\frac{35}{f_{cm}}\right]^{0.5} \tag{15}\]  
The effect of the type of cement on the creep coefficient of concrete may be taken into account by modifying the age \(t_{0}\) at loading in accordance with Equation (15)  
\[t_{0}=t_{0,T}\left[\frac{9}{2+t_{0,T}^{1.2}}\right]^{\alpha}\geq 0.5\text{ days} \tag{16}\]  
where \(t_{0,T}\) is the age of concrete at loading (days) adjusted according to Equation (13), \(\alpha\) is the power which depends on the type of cement (\(\alpha=-1\) for cement Class S, \(\alpha=0\) for cement Class N, \(\alpha=1\) for cement Class R). The effect of elevated or reduced temperatures within the range 0-80 \({}^{\circ}\)C on the maturity of concrete may be taken into account by adjusting the concrete age according to the following expression:  
\[t_{T}=\sum_{i=1}^{n}e^{-(4000/[273+T(\Delta t_{i})]-13.65)}\Delta t_{i} \tag{17}\]  
where \(t_{T}\) is the temperature adjusted concrete age which replaces \(t\) in the corresponding equations, \(T(\Delta t_{i})\) is the temperature in \({}^{\circ}\)C during the time period \(\Delta t_{i}\), \(\Delta t_{i}\) is the number of days where a temperature \(T\) prevails. For stress levels in the range of \(0.4f_{cm}(t_{0})<|\sigma_{c}|<0.6f_{cm}(t_{0})\) the nonlinearity of creep may be taken into account using Equations (14)  
\[\phi_{0,k}=\phi_{0}e^{\alpha_{c}(k_{c}-0.4)} \tag{18}\]where \(\phi_{0,k}\) is the non-linear notional creep coefficient, which replaces \(\phi_{0}\) in Equation (A6), \(k_{\sigma}~{}=~{}\sigma_{c}/f_{cm}(t_{0})\) which is the stress-strength ratio, \(\alpha_{\sigma}=1.5\). The total shrinkage strain, \(\epsilon_{cs}(t)=\epsilon_{cd}(t)+\epsilon_{ca}(t)\), is composed of two components, the drying shrinkage strain, \(\epsilon_{cd}(t)\), and the autogenous shrinkage strain, \(\epsilon_{ca}(t)\). The development of the drying shrinkage strain in time follows from  
\[\epsilon_{cd}(t)=\beta_{ds}(t,t_{s})k_{h}\epsilon_{cd,0}\quad\text{ with }\quad\beta_{ds}(t,t_{s})=\frac{t-t_{s}}{t-t_{s}+0.04\sqrt{h^{3}}}\quad\text{ and }\] (A16) \[\epsilon_{cd,0}=0.85\left[(220+110\alpha_{ds1})\text{exp}\left(- \alpha_{ds2}\frac{f_{cm}}{f_{cm0}}\right)\right]10^{-6}\left\{-1.551\left[1- \left(\frac{RH}{RH0}\right)^{3}\right]\right\}\]  
where \(k_{h}\) is a coefficient depending on the notional size \(h\) [mm] as  
\[k_{h}= \begin{cases}1&\text{for }\ h_{0}=100,\\ 0.85&\text{for }\ h_{0}=200,\\ 0.75&\text{for }\ h_{0}=300,\\ 0.70&\text{for }\ h_{0}\geq 500.\end{cases}