# Binary Mixes of Self-Compacting Concrete with Municipal Solid Waste Incinerator Bottom Ash
## 4 Conclusions  
This study had the objective of determining the effects of using milled bottom ashes from incinerated municipal solid waste in the performance of self-compacting concrete. It was carried out within the scope of a larger research project aiming to valorise this waste in the production of new construction materials. One other objective of the current study was also to contribute to the wider dissemination of self-compacting concrete and its capacity to incorporate significant amounts of MIBA, leading to greater implementation of this type of concrete in current practice. The conclusions obtained from this study are the following:  
* In the slump-flow and V-funnel tests, all mixes presented fluidity, flow rate and viscosity perfectly adjusted to that established in the normative requirements. As for the flow requirements in the L-box test, the mixes C20 BA and C50 BA presented the worst performance. Even so, the results were deemed as acceptable and, together with the visual analysis carried out during the execution of the test, it is possible to ensure that the produced SCCs present adequate fluidity and flow capacity. * As for the mechanical performance, the C20 BA mixture presents the most favourable overall results of mixes containing MIBA. The rest of the mixtures present considerably higher performance losses, particularly the mixtures C40 BA and C50 BA, which did not present enough compressive strength for a real structural situation. * Regarding the durability-related performance, SCCs produced with MIBA present a promising behaviour. The C20 BA mixture stood out as the most advantageous mixture with MIBA, presenting values very similar to those of the RC mixture for most of the studied properties. The C50 BA mixture, on the other hand, presented the worst behaviour of all the mixtures. Although the MIBA led to a decline in mechanical properties, evaluating the overall performance of the resulting concrete, as long as the percentage of replacement does not exceed 20%, the MIBA can prove to be promising, since it does not significantly hinder the fresh behaviour of the SCC and represents a new value-added solution for bottom ashes from incinerated municipal solid wastes. Nevertheless, it is recommended that additional research be carried out, especially on the use of pre-treated MIBA in order to eliminate the expansion due to the oxidization of aluminium particles, which is the primary cause for the decline in performance. Assuming that adequate performance levels are attained under these circumstances, MIBA can be considered as an alternative mineral addition capable of partially replacing cement in the production of concrete for several applications  
Figure 11: Electrical resistivity coefficient (\(\Omega\).m) at 28 and 91 days. in construction. Furthermore, future research should also focus on an in-depth life cycle assessment, as it is crucial to understand the implications of using MIBA in current practice. It is especially important given the decline in performance when using the addition and what would be the necessary changes in the mix design to consider a functional unit of, for example, one cubic metre of concrete with equivalent mechanical and durability properties in order to carry out an adequate comparative analysis. [PERSON] and [PERSON] conceived and designed the experiments; [PERSON] performed the experiments; [PERSON] and [PERSON] analysed and validated the methodology and results; [PERSON] and [PERSON] wrote the paper. All authors have read and agreed to the published version of the manuscript. This research was funded by Instituto Politecnico de Lisboa (IPL) through the scientific research project \"ECOncrete--Production of self-compacting concrete with municipal solid waste incinerator bottom ash (IPL/2017/ECOnCreate/ISEL)\" and FCT- Foundation for Science and Technology through the research project PTDC/ECI- CON/29196/2017 \"Recycled Inorganic Polymer Concrete: Towards a fully recycled and cement-free concrete\" (RInoPolyCrete). Not applicable.