<![CDATA[ABSTRACT Cement Portland is an essential ingredient in infrastructure development, but in portland cement production, there is a release of carbon dioxide (CO2). Innovation in materials in the construction of mortars, namely geopolymer mortars, is expected to reduce cement and air pollution. The research using experimental methods, aimed at locating the effect of the use of silica fume and quick lime with variations of silica fume: quick lime 90:10, 80:20, 70:30, 60:40, 50:50, using a cube mold of 5 x 5 x 5 cm as much as 120 items, for testing age 7, 14, 28 days. Research has a compressive strength with an optimum geopolymer mortar on a variation of silica fume: quick lime 70:30, which is 3.52 MPa at the age of 28. Based upon compressive strength results, apply the age of mortar 7, 14, 28 days known the longer a strong mortar age agency. Silica fume and quick lime may be used as alternative materials to replace cement. Based on ASTM C 270 to imply mortars type K and type O. ABSTRAKSemen portland merupakan bahan material penting dalam pembangunan khususnya di bidang teknik sipil, namun dalam proses produksi semen portland terjadi pelepasan karbon dioksida (CO2). Perlu adanya inovasi bahan dalam pembuatan mortar yaitu mortar geopolimer yang diharapkan dapat mengurangi penggunaan semen dan polusi udara. Penelitian ini menggunakan metode eksperimental, bertujuan mengetahui pengaruh penggunaan silica fume dan kapur tohor terhadap mortar geopolimer dengan variasi silica fume:kapur tohor 90:10, 80:20, 70:30, 60:40, 50:50, benda uji berbentuk kubus berukuran 5 x 5 x 5 cm sebanyak 120 benda uji, pengujian umur 7, 14, 28 hari. Hasil penelitian didapat kuat tekan optimum mortar geopolimer pada variasi silica fume:kapur tohor 70:30 yaitu 3,52 MPa pada umur 28 hari. Berdasarkan hasil kuat tekan pengaruh umur mortar 7, 14, 28 hari diketahui semakin lama umur mortar kuat tekan semakin meningkat. Silica fume dan kapur tohor dapat digunakan sebagai bahan alternatif pengganti semen. Berdasarkan ASTM C 270 termasuk dalam mortar tipe K dan tipe O.]]>
