# Jointing Principles in AMC--Part 1: Design and Preparation of Dry Joints
## 3 Joint Catalogue
### Evaluation Criteria and Scoring
#### 3.1.4 Duration of Manufacturing  
The evaluation criteria \"duration of manufacturing\" describes the time required to manufacture a joint profile with the techniques mentioned in Section 3.1.1. As there are many post-processing techniques available, all joint productions are correlated to CNC-milling because most of the joint profiles can be manufactured by this technique. As the height of the milling is always set to 10 mm, the milling volume is not sufficient to evaluate the duration. For example, a fungal joint profile has the same milling volume as a triangular joint profile but a more complex geometry. Due to the complex geometry, the manufacturing duration is assumed to be higher than the simpler geometry. So instead of the milling volume, the joint's surface area is considered to evaluate the duration of manufacturing. If the surface of a joint profile is, e.g., higher than 200 cm\({}^{2}\), the CNC-milling required a lot of time, and the joint gets a low score. The profile where the surface is between 100 and 120 cm\({}^{2}\) gets highest score. Table 5 lists the ranges of the surface areas belonging to the scoring.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{-} & \multicolumn{5}{c}{**Score**} \\ \hline
**Criteria** & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) \\ \hline
[-] & [-] & [-] & [-] & [-] & [-] & [-] \\ \multirow{2}{*}{Connectivity Calculation basis} & Axial, lateral, & radial & axial * & axial, radial & axial, lateral, radial \\  & radial & lateral & lateral, radial & axial, lateral & axial, lateral, radial \\ \multirow{2}{*}{Calculation basis} & No connectivity by any means & 1 & 2 or 1 + 1 & 2 + 1 & 2 + 1 + 1 \\ \hline \hline \end{tabular}  
* Axial alone gets a score of two due to the most similarity with the real construction field.  
\end{table}
Table 4: Scoring in evaluation criteria “connectivity in a structure”.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{-} & \multicolumn{5}{c}{**Score**} \\ \hline
**Criteria** & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) & \(\square\) \\ \hline
[-] & [cm\({}^{2}\)] & [cm\({}^{2}\)] & [cm\({}^{2}\)] & [cm\({}^{2}\)] & [cm\({}^{2}\)] \\ \multirow{2}{*}{Duration of manufacturing} & \multirow{2}{*}{\(O_{\text{j}}\geq 200\)} & \multirow{2}{*}{\(200>O_{\text{j}}\geq 160\)} & \multirow{2}{*}{\(160>O_{\text{j}}\geq 140\)} & \multirow{2}{*}{\(140>O_{\text{j}}\geq 120\)} & \multirow{2}{*}{\(120>O_{\text{j}}\geq 100\)} \\  & & & & & & \\ \hline \hline \end{tabular}  
\end{table}
Table 5: Scoring in evaluation criteria “duration of manufacturing”.  
Besides the geometric approach for evaluating the manufacturing duration in Table 5, preliminary CNC-milling tests are supposed to confirm the assumptions. Therefore, rectangular concrete specimens were subtractive post-processed by CNC-milling. The smooth (Figure 4a), arc (Figure 4b), trapezoid (Figure 4c) and sinusoidal (Figure 4d) joint profiles were manufactured, and their durations of manufacturing were measured. Figure 4 shows the samples with the joint profiles, the duration of manufacturing and the calculated area of the surface.  
The results of the duration measurement show that it correlates with the surface of the joint profile. Preparing a smooth joint with CNC-milling only took 18 min. A preparation with other subtractive post-processing, like a water jet or a circular saw, might be even faster. CNC-Milling of an arc, trapezoid or sinus wave joint configuration took quite a long time, respectively, 74, 97 and 106 min. Besides the area of the joint surface that correlates with the duration of manufacturing, trapezoid, arc, and sinus wave joint profile types also required more than one milling tool. The more complex the joint profile is, the more tools are required, and the duration of manufacturing rises.