# Durability Issues and Corrosion of Structural Materials and Systems in Farm Environment
## 4 Mitigation of Corrosion
### Design for Durability  
The construction of agricultural structures, materials that offer optimal production against corrosion such as fly ash and silica fumes-infused concrete, does not provide the absolute guarantee for enhancing the durability of farm structures [29]. The observation is reinforced by the growing role of durability design--based on building codes and the incorporation of materials that satisfy the prerequisite requirements. For example, a research by [PERSON] and co-researchers showed that different concrete mixes (such as SSFC, SFC, PC40 (Portland cement concrete with a 0.4 W/CM ratio), and FASF) offered different levels of protection against hydrogen sulfide attacks after 8, 16, and 32 cycles. The least visual evidence of corrosion was reported in the SR (sulphate-resistant cement -CEM IIIB) concrete mix [30]. Beyond, the customization of the concrete structure application, the design for durability also encompasses the integration of adhesives and coatings and other surface modifications that are employed to improve the service life of the concrete structure.  
Eurocode 2 (EN 1992-1-1 [35]) provided information for the durability design of concrete structures. Farm structures with high humidity are categorized as XC3 and with chemical attacks XA2 or XA3 depending to the conditions. For XC3, minimum concrete C35/45 and more than 15 mm of cover are required. For XA2 or XA3, special concrete composition is required according to Section 6 of EN 206-1 [36] together with the minimum required cover per EN 1992-1-1 [35].  
Adhesives for Concrete  
Various adhesives have been developed to augment the durability of the concrete structure, including epoxy-cement paste, which is made of epoxies such as bisphenol A and resins such as modified cycloaliphatic amine and modified aliphatic and aromatic amines [31; 32]. The epoxy paste forms a robust bond with cement via silane surface functionalization (mechanical interlocking and hydrogen bonding); the net effect is better functionality of the material and resistance to moisture [32]. Similar observations were made by [PERSON] and co-researchers. However, the strength of the bond was influenced by the thickness of the epoxy, especially in the development of the shear strength of the concrete structure [31]. In addition, the effectiveness of the epoxy resin was also influenced by temperatures. Considering that the adhesives have limited thermal stability, elevated temperatures (\(>\)65 \({}^{\rm o}\)C) diminish the mechanical strength of the epoxy resins by up to 90% [33]. The effectiveness of the adhesive was dependent on the ratios of the hardening agent and the resin, as shown in Figure 7. The thickness of the layers deposited varied between 1 mm and 3 mm. The epoxy resin with aromatic amines with a thickness of 4 mm exhibited the highest resistance against shear strain. In contrast, epoxy resins with a thickness of 7 mm exhibited the highest resistance against shear stress [34]. Apart  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Binder** & **CaO** & **SiO\({}_{2}\)** & **Fe\({}_{2}\)O\({}_{3}\)** & **Al\({}_{2}\)O\({}_{3}\)** & **MgO** & **MnO** & **K\({}_{2}\)O** & **Na\({}_{2}\)O** & **TiO\({}_{2}\)** & **SO\({}_{3}\)** \\ \hline GU & 62.5 & 19.6 & 2.27 & 4.9 & 2.61 & 0.05 & 0.9 & 0.24 & 0.25 & 2.57 \\ AC & 36.82 & 4.61 & 16.21 & 38.47 & 0.68 & 0.77 & \textless{}0.02 & 0.04 & 1.75 & - \\ SF & 0.50 & 94.17 & 0.32 & 0.21 & 0.47 & 0.07 & 1.17 & - & - & 0.12 \\ FA & 1.87 & 42.2 & 27.60 & 21.60 & 0.92 & - & 2.55 & 0.66 & - & 1.10 \\ MK & 0.03 & 51.65 & 0.68 & 44.7 & 0.08 & - & 0.34 & 0.08 & 0.12 & - \\ GBFS & 37.31 & 36.77 & 0.85 & 7.77 & 13.91 & 1.02 & 0.43 & 0.31 & 0.36 & - \\ \hline \hline \end{tabular}
\end{table}
Table 12: Chemical composition of the cement binder or additive [28]. The measurement units are ratios - no specific SI units.  
from reinforcing bonds in concrete structures, adhesives are also used in steel structures using a similar mechanism as concrete applications.