[ID] Inovasi material maju yang ramah lingkungan dilakukan dengan mengembangkan material konstruksi yang berasal dari limbah. Salah satunya adalah beton geopolimer yang memanfaatkan limbah fly ash sebagai pengganti semen dan recycled concrete aggregate (RCA) sebagai alternatif pengganti agregat kasar. Penggunakan limbah diharapkan dapat meningkatkan kualitas beton geopolimer. Tujuan penelitian adalah untuk menganalisis pengaruh substitusi recycled concrete aggregate terhadap kuat tekan beton geopolimer. Metode penelitian menggunakan studi eksperimental di laboratorium berdasarkan SNI 03-6825-2002 pada kuat tekan. Rancangan benda uji menggunakan molaritas aktivator 12M dan perbandingan katalitasator berupa Na2SiO3 (SH) dengan aktivator berupa KOH (SS) sebesar 2:1. Variasi subtitusi recycled concrete aggregate yang digunakan yaitu 0%, 25%, 50%, 75% dan 100% terhadap berat agregat kasar. Benda uji beton berbentuk silinder dengan diameter 10 dan tinggi 20 cm untuk pengujian kuat tekan sesuai dengan SNI 2847:2019. Pengujian kuat tekan digunakan pada umur 28 hari dengan perawatan suhu ruang. Hasil penelitian diperoleh nilai kuat tekan rata-rata dengan substitusi RCA 0%, 25%, 50%, 75%, 100% secara berurutan yaitu sebesar 2,89 MPa; 2,93 MPa; 3,27 MPa; 3,82 MPa dan 3,26 MPa. Nilai kuat tekan tertinggi diperoleh pada substitusi RCA sebesar 75% dan nilai kuat tekan rata-rata beton geopolimer mengalami peningkatan seiring dengan adanya penambahan substitusi RCA namun mengalami penurunan pada substusi RCA sebesar 100%. Hasil analisis kuat tekan beton geopoliner dengan metode analysis of variance diperoleh nilai Fhitung > Ftabel yaitu 3,52 > 3,11, sehingga dapat dinyatakan bahwa variasi substitusi recycled concrete aggregate berpengaruh terhadap nilai kuat tekan beton geopolimer [EN] Advanced material innovations that are environmentally friendly are carried out by developing construction materials derived from waste. One of them is geopolymer concrete that utilizes fly ash waste as a substitute for cement and recycled concrete aggregate (RCA) as an alternative to coarse aggregate. Waste users are expected to improve the quality of geopolymer concrete. The purpose of the study is to analyze the effect of recycled concrete aggregate substitution on the compressive strength of geopolymer concrete. The research method uses experimental studies in the laboratory based on SNI 03-6825-2002 on compressive strength. The design of the test piece uses an activator molarity of 12M and a ratio of the catalyst in the form of Na2SiO3 (SH) with the activator in the form of KOH (SS) of 2:1. The variations of recycled concrete aggregate substitution used are 0%, 25%, 50%, 75% and 100% to the weight of the coarse aggregate. Cylindrical concrete test piece with a diameter of 10 cm and a height of 20 cm for compressive strength testing in accordance with SNI 2847:2019. Compressive strength testing is used at 28 days of age with room temperature treatment. The results of the study obtained an average compressive strength value with RCA substitution of 0%, 25%, 50%, 75%, 100% respectively, which was 2,89 MPa; 2,93 MPa; 3,27 MPa; 3,82 MPa and 3,26 MPa. The highest compressive strength value was obtained in RCA substitution of 75% and the average compressive strength value of geopolymer concrete increased along with the addition of RCA substitution but decreased in RCA substitution by 100%. The results of the compressive strength analysis of geopolitan concrete by the analysis of variance method obtained the value of Fcal > Ftabel which is 3,52 > 3,11, so it can be stated that the variation of recycled concrete aggregate substitution has an effect on the compressive strength value of geopolymer concrete