Grain breakage in demolition waste from Maceió (AL) induced by CBR tests

Resumen

This study investigates the grain breakage behavior of demolition waste (DW) sourced from five districts of Maceió, Brazil, affected by ground subsidence resulting from rock salt extraction. The research evaluates the feasibility of reusing this material in urban pavement layers. Geotechnical characterization included particle-size analysis, Normal and Intermediate Proctor compaction tests, California Bearing Ratio (CBR), and X-ray diffraction to assess mineralogical composition. The objective was to examine how compaction energy influences particle fragmentation. Results showed that higher compaction energy increases material densification and reduces optimum moisture content but intensifies particle breakage, particularly within the gravel-sized fraction. Breakage indices (B45 and B75) indicated greater susceptibility of larger particles to fragmentation under the Normal Proctor effort. In contrast, the Intermediate Proctor test resulted in lower degradation and improved particle interlock, enhancing mechanical performance. Overall, the findings indicate that DW exhibits technical potential for use as a subgrade reinforcement layer when compacted under controlled conditions. The study underscores the relevance of recycling demolition materials as a sustainable engineering practice, reducing the demand for natural aggregates and promoting solutions aligned with circular economy principles.