# Durability Assessment of Eco-Friendly Bricks Containing
## 6 Conclusions and Recommendations  
In this study, strength properties considering the CS and FS tests, as well as durability properties considering the freeze-thaw (F-T), mercury intrusion porosimetry (MIP), and water absorption (WA) tests, were used to determine the durability of green bricks produced with LKD, GGBFS, and TRW waste. From the laboratory experiments, analysis, and validations performed, the following conclusions can be drawn:  
* The brick samples produced with 0, 5, and 10% TRW had CS and FS results of 6.17, 5.25, and 3.09 MPa and 2.52, 2, and 1.55 MPa respectively. As standards require, these bricks passed the specifications for load- and non-load-bearing units for small buildings [49]. Additionally, the bricks produced with up to 10% TRW replacement passed the FS requirements for concrete bricks, which range between 1.4 and 3.4 MPa [69]. Thus, it can be concluded that the bricks produced with up to 10% TRW passed the CS and FS requirements for masonry units that can be used in small buildings. * The power model developed in this study can be used to predict the flexural strength of the green bricks in the absence of a test. However, verification of the model considering different cementitious materials, types and sizes of aggregates, curing durations, and curing regimes can be performed. * For the F-T tests, the brick samples produced with 0% TRW were seen to have no physical changes after 10 cycles of F-T. Hence, the samples produced with 0% TRW can be classed as frost-resistant bricks or frost-durable bricks, which can be used in environments where temperatures can be as low as \(-43\)\({}^{\circ}\)C. The samples with 5 and 10% TRW had some physical changes on their surface in terms of delamination. Hence, the bricks produced with 5 and 10% TRW are not recommended for cold regions where temperatures can drop as low as \(-43\)\({}^{\circ}\)C.  
Figure 12: Water absorption levels in the rubberized bricks. * The results of the MIP tests carried out on the brick samples containing 0, 5, and 10% TRW showed that two distinct pore sizes were present in the bricks. The bricks that had 0% TRW fell under the durable region, which was confirmed by their surface appearance after the F-T cycles. Furthermore, a peak intrusion volume of 0.095 mL/g was recorded for the 0% TRW (F-T), after which the curve flattened. This translates to durability, irrespective of the effect of the F-T cycles. The brick samples containing 5 and 10% TRW fell within the uncertain and non-durable regions, respectively, which can be attributed to the presence of the TRW in the bricks. * WA tests performed on the samples showed that the bricks met the <20% standard requirements for WA. The WA values recorded for the bricks that contained 0, 5, and 10% TRW were 7.25, 11.76, and 14.96%, respectively. In conclusion, the bricks assessed in this study passed all of the durability tests performed. However, it is recommended that further studies using a smaller amount of TRW (<5%) should be performed to investigate the durability (F-T and MIP) properties of the green bricks. J.A.O. : Formal Analysis. J.A.O. and H.A.-N.: Conceptualization, Methodology, Writing--Original Draft. H.A.-N.: Supervision, Validation. J.A.O. and H.A.-N.: Writing--Review and Editing. All authors have read and agreed to the published version of the manuscript. This research was supported by the Tertiary Education Trust Fund (TETFund). Not applicable. The data presented in this study are available on request from the corresponding author. The data are not publicly available due to ethical restrictions. The first author acknowledges the Tertiary Education Trust Fund (TETFund) for funding her studies at La Trobe University, Melbourne, Australia. Furthermore, the authors wish to express their earnest appreciation to Cement Australia for the free LKD waste, and GGBFS samples, and Sika Australia Pty. Ltd., Melbourne, for the free WRA (Sika Plastiment-45) samples that were donated to support this research. The authors declare that they have no conflicts of interest.