PENAMBAHAN ABU BONGGOL JAGUNG SEBAGAI ACCELERATOR TERHADAP SETTING TIME DAN KUAT TEKAN MORTAR BERBASIS SEMEN TIPE I

corn cob ash is an agriculutural waste that hasn't been use for many thing. people often see them as a junk or literally a garbage. corn cob ash also have a great mount of silica. a research tried to make use of a corn cob ash as a sand replacement inside a concrete. a research once used corn cob ash as a sand replacement. sand is a matter that contain silica and alumina. there's a research of using corn cob ash waste as a material composition for mortar. mortar is a contruction material that has been made from a mixture of cement, sand, and water with different percentage. the concept are only for making use of corn cob ash as a mineral admixture for a creation of mortar cement type 1 that gives a spesific strength, with w/c (water/cement) ratio 0.6 and with 0-100% mix design admixture material and endurance test at 3,7 mpa every 28 days. tests were ran with Setting Time, compressive strength, XRF, and SEM. the results shows that corn cob ash act for hasten the hidration or as an accelerator for the mortar from 390mins reduced to 240mins on 50% corn cob ash. an addition of corn cob ash affects the compressive strength. 25% addition is a maximum compotition that gives a best result at 8.82 MPa on 28th day. SEM result shows corn cob ash mortar has slightly form a crack from the test. the test were higher than mortar controll and corn cob ash mortar.