Pemanfaatan fly ash tipe c dan perlite sebagai material subtitusi semen dan pasir pada pembuatan beton ramah lingkungan

The construction industry's high cement consumption significantly increases carbon dioxide (CO₂) emissions during production. This study experimentally analyzes the effects of substituting 15% Type C fly ash for cement and varying perlite  proportions for fine aggregate on concrete properties, using normal concrete as the control mix across several perlite  variations. Parameters evaluated include workability  via slump  test, unit weight, and compressive strength at 28 days of curing. Results indicate that the incorporation of 15% fly ash with varying perlite  percentages enhances fresh concrete workability , with the highest slump  value reaching 100.74 mm. The effect of perlite  on unit weight was inconsistent across mix proportions; the lowest unit weight of 2,194.34 kg/m³ was recorded in the 15% fly ash and 2.5% perlite  mix, while the 10% perlite  mix yielded a higher unit weight of 2,283.02 kg/m³ than normal concrete at 2,245.28 kg/m³. In terms of compressive strength, normal concrete reached 12.93 MPa, while the 15% fly ash mix without perlite  achieved the highest value of 22.52 MPa. Among combined mixtures, compressive strength varied non-linearly with increasing perlite  content, ranging from 10.07 MPa (2.5%) to 15.39 MPa (7.5%), with the optimal perlite  proportion identified at 7.5%, surpassing the compressive strength of normal concrete. In terms of environmental impact, the 15% fly ash substitution reduced CO₂ emissions by 51.96 kg CO₂/m³, equivalent to a 14.5% decrease compared to normal concrete, supporting decarbonization efforts in the construction sector.