**4. Insights and Discussions**

By analysing the results, many interesting insights can be gained. For the purpose of this study, only the most critical insights are discussed in this section; other advanced information may be obtained from the detailed results in the appendices.

#### *4.1. For Method Applications*

## 4.1.1. Insights for Data Pre-Processing Results

During data curation and pre-processing (see Section 3.1), the fresh properties of HPC are excluded because of data incompatibility, and only the hardened mechanical and durability property data at day 28, day 56 and day 91 are utilised for analysis due to data commonalities (i.e., they provide equal-sized data variables and have overlaps in testing time), despite the fact that the frequency of data recording for the experiment is typically predefined [39]. This experience will be useful for locating commensurable HPC testing data during any future analysis.
