# Nanomaterials' Influence on the Performance of Thermal Insulating Mortars--A Statistical Analysis
## 4 Conclusions  
This statistical approach allowed us to better understand the characteristics of current thermal insulating mortars, transforming data into knowledge. With this analysis, it was possible to identify and evaluate the influence that formulations and thermal insulating aggregates have on the performance of these mortars, and the following findings can be highlighted:  
* With the uni and bivariate analysis, it was possible to confirm: correlations between the ratio water:powder (_w/p_) and the remaining variables; the influence that kneading water has on the mortars' performance; correlations between the bulk-density hardened state (_BDh_) and the bulk-density fresh state (_BDf_), and correlations between compressive strength (_fc_), the dynamic modulus of elasticity (_Ed._), and flexural strength (_ft_), and other more interesting ones, such as between _BDh_, _A10\({}^{\circ}\)C,28 days_, and _A10\({}^{\circ}\)C,dry_;
* PCA and factor analysis allowed us to identify three main components, the latent structure of which allowed us to classify them into the following categories: thermo-mechanical, internal cohesion, and microstructural porosity, and water permeability behaviours. Here, the most relevant finding was the achievement of a factor showing a significant impact of the use of nanomaterials as thermal insulating aggregates, where the increase in mechanical performance decreases the thermal performance. So, both the formulation and the addition of thermal insulating aggregates, like the silica aerogel, influenced their behaviour;
* With the cluster analysis, the findings of PCA were enhanced and verified. Three groups of formulations were obtained, showing the importance that nano thermal insulating aggregates, in conjunction with the base formulations (laboratory, industrial, or industrial tuned in the laboratory), have on the overall performance;* Although simple and multiple linear regression models were studied, the simplest model was the one with the best results. Therefore, it was possible to obtain a new model that can allow researchers to save time, allowing them to predict \(\lambda_{10}\)\({}^{\circ}\)_C,dry_ earlier. The extensive statistical analysis conducted allowed us to verify that the most significant influences on the performance of these mortars are related to the use of nanomaterials and their higher need for kneading water to reach the desired workability. This excess water, after the initial hydration reactions, leaves voids, pores, and capillaries in the microstructure. The conjunction of both factors leads to lower thermal conductivities, but also decreased mechanical performances, showing a need for further development. Nevertheless, the introduction of thermal insulating nanomaterials allowed us to obtain thermal conductivities below classic thermal insulating materials. This was not possible before, using other types of thermal insulation aggregates; therefore, it is a great achievement in reducing the oil needs (e.g., for EPS manufacture) of these mortars, with significant potential to improve their sustainability. As current formulations seem only to introduce additional thermal insulating aggregates into existing formulations, looking at the results of this research, it would be beneficial to approach these products from a distinct perspective--that is, to design entirely new formulations instead of only adding thermal insulating aggregates. The methods and techniques applied in this research present a new critical view on current thermal mortars' performance, namely on how they can be further fine-tuned as multifunctional products. Here, the final application and performance needs will dictate the formulations' design. The future thermal mortar formulations would, preferably, present low thermal conductivities and water absorption while having high water vapour permeability and mechanical properties. This seems to be partially achieved using nanomaterials, such as silica aerogel.