# Jointing Principles in AMC--Part 1: Design and Preparation of Dry Joints
## 3 Joint Catalogue
### Algorithm  
The algorithms should be kept easy in handling and calculation. The algorithm is a simple approach where the score \(S_{\text{i}}\) of the evaluation criteria is multiplied by the weighting factors \(X_{\text{i}}\) and sum up to the overall score \(S_{\text{EC}}\). Equation (2) shows the formula for the algorithm.  
\[S_{\text{EC}}\ =\ \sum_{n\ =\ 1}^{i}X_{\text{i}}\cdot S_{\text{i}} \tag{2}\]  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Criteria** & **Weighting Factor** \\ \hline Manufacturability & 2 \\ Connectivity & 2 \\ Detachability & 1 \\ Duration & 2 \\ Joint quality & 1 \\ Tensile strength & 1 \\ Shear strength & 3 \\ Torsional strength & 1 \\ Compressive strength & 3 \\ Failure Mode & 1 \\ FE analysis & 3 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Weighting factors of evaluation criteria.  
Figure 7: Exemplary evaluation of the compressive strength: (**a**) triangular (**b**) saw tooth and (**c**) trapezoid joint.  
Furthermore, the algorithm gives the possibility of flagging. Flagging means that the joint will not be evaluated by any criteria. The flags are divided into two colours: green and red. A green flag leads to a direct selection of the flag for further numerical and experimental investigations. A red flag means that the joint profile is not suited for concrete constructions and will not be regarded for evaluation. Table 8 shows the joint profiles that have the highest overall score calculated by the algorithm.  
Based on the results, AMC's best joint profile is the triangular profile with an overall score of 50 out of 68 possible points. It has a desirable behaviour in shear and is easy to produce. The saw-tooth, sinus wave, arc and truncated pyramid profiles also have a noticeably high overall score and are well suited for AMC structures. It is remarkable that the trapezoid joint, which is already established in the segmental building industry, has only a score of 38.5. The reason might be the different perspec  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Joint Profile** & **Category** & **Drawing** & **Score** \\ \hline Triangular & Line-shaped & & 50 \\ Saw tooth & Line-shaped & & 49 \\ Sinusoidal & Line-shaped & & 47.5 \\ Arc & Line-shaped & & 47.5 \\ Trapezoid & Line-shaped & & 38.5 \\ Dovetail & Line-shaped & & 28.5 \\ Fungal & Line-shaped & & 29 \\ Shell & Point-shaped & & 38.5 \\ Inner Circle & Point-shaped & & 37.5 \\ Cross & Point-shaped & & 37.5 \\ Truncated cone & Pont-shaped & & 40.5 \\ Truncated pyramid & Point-shaped & & 49.5 \\ Smooth & Mesh-shaped & & 45 \\ Chequerboard & Mesh-shaped & & Red flag \\ Lego & Mesh-shaped & & 36 \\ Fish-scale & Mesh-shaped & & 41 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Joint profiles with score of algorithm.  
tive of the conventional building industry compared to the digital building industry, like AMC. In AMC, other criteria, like the joint quality or the duration of manufacturing, for choosing a joint profile are more important compared to in the conventional building industry.  
Dovetail and fungal joints are rated as the most inappropriate connection types. The main disadvantage of these joints is the elaborate manufacturing necessary in the case of concave surfaces. Another point against the dovetail and fungal joints is the connectivity in the entire structure because they can only be fitted in one direction. However, they are joints that can transfer tensile forces. However, transferring tensile stresses in unreinforced concrete structures is generally risky due to brittle material behaviour.