## 4 Conclusions  
This study investigated self-compacting lightweight concrete using lightweight aggregates from the reuse of agro-industrial and mining waste, specifically sugarcane biomass ash (SBA) and schelite mining residue (SMR). An experimental campaign was conducted to compare these unconventional aggregates with commercially available expanded clay aggregates in Brazil. The results highlight the following key points:  
* The results of the slump flow test showed that all concretes studied met the self-compacting characteristics. However, the SCLC-EC and SCLC-SBA50 mixtures demonstrated better performance, making them suitable for most reinforced concrete applications, according to [28]. * Regarding viscosity measurement, assessed by the T500 test, it was found that an increase in the consumption of both fine and coarse aggregates contributed to higher viscosity in the concretes. The SCLC-SBA90, followed by the SCLC-SBA50, the SCLC-SMR37, and lastly, the SCLC-EC, showed the longest flow time and, consequently, the highest viscosity. * In terms of passing ability, all concretes were equally classified as suitable for most applications. However, among the results, the SCLC-EC exhibited a better ability to overcome obstacles due to its self-compacting nature when compared to concretes with non-conventional aggregates, with SCLC-SBA90 displaying the greatest difficulty. However, visual stability indices indicated no evidence of segregation and/or bleeding in the mixtures, where all presented uniform flow and homogeneous behaviour between the paste and aggregate. * The SCLC-EC and SCLC-SMR37 concretes showed the lowest specific mass values in the fresh state, while the SCLC-SBA50 and SCLC-SBA90 showed values exceeding the 2.00 g/cm\({}^{3}\) limit. The same trend was observed in the determination of air-dried specific mass, except for SCLC-SBA50, which remained within the limit. Nonetheless, the values exceeding the specified limit for lightweight concrete can still be classified as such, given the minimal variation. * All studied concretes met the minimum compressive strength values for structural lightweight concrete. The SCLC-EC showed the best performance in terms of strength gain (41.4%); however, the SCLC-SMR37 achieved the highest strength values at 7 days (26.35 MPa) and 28 days (34.15 MPa). Additionally, an inversely proportional relationship was observed between the increase in lightweight aggregate content in the mix and the strength gain from 7 to 28 days, with SCLC-SBA90 and SCLC-SBA50 displaying the lowest strength gains of 23.1% and 18.4%, respectively. Overall, although the concrete with the commercial aggregate showed a more satisfactory performance in both fresh and hardened properties, the other concretes also met the pre-established requirements and can, thus, be classified as self-compacting lightweight concrete using more sustainable regional lightweight aggregates. **Author Contributions:** Conceptualisation: M.A.S.d.A. ; Methodology: M.A.S.d.A., J.T.F.d.S. and E.C.d.F. ; Validation: M.A.S.d.A., J.T.F.d.S. and E.C.d.F. ; Formal analysis: M.A.S.d.A., J.T.F.d.S., E.C.d.F., J.A.d.S.N., F.G.B. and C.M.P. ; Investigation: M.A.S.d.A., J.T.F.d.S. and E.C.d.F. ; Resources: M.A.S.d.A. ; Writing original draft: M.A.S.d.A., E.C.d.F. and J.A.d.S.N. ; Writing review and editing: J.A.d.S.N., F.G.B. and C.M.P. ; Visualisation: M.A.S.d.A., E.C.d.F., F.G.B. and C.M.P. ; Supervision: M.A.S.d.A. and E.C.d.F. ; Project administration: M.A.S.d.A. and F.G.B. ; Funding acquisition: M.A.S.d.A. and F.G.B. All authors have read and agreed to the published version of the manuscript. **Funding:** This research received no external funding. **Data Availability Statement:** Data is contained within the article.