PENGARUH PEMANFAATAN FELDSPAR SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN PADA KUAT TEKAN MORTAR

Indonesian territory is one of the countries that has a strategic geological location, producing reserves that are rich in natural minerals. Nowadays, the demand for cement is very high, which is required for cement to be difficult to obtain and is relatively expensive. Therefore there needs to be something alternative material that can reduce the level of cement but not reduce the level of cement itself, one of which is feldspar. Feldspar is a silicate mineral that forms a framework in the structure of SiO2 silica tetrahedral, mineralogically feldspar is grouped into Plagioclase and K-Feldspar. This research is to find out how the influence of feldspar as cement. This research begins with XRD X-Ray Diffraction testing to study the characteristics of the mineral feldspar and then make 54 (fifty-four) mortar specimens with variations in the mixture of 0%, 20%, 40%, 50%, 60%, and 80% feldspar attend the cement mass. Mortar testing is done by rotating the binding time and the strength of the pressure that occurs in the mortar. Based on the conclusions obtained, the use of murmi feldspar as cement in mortar can be used to manufacture grade 1 (one) quality walls with a compressive strength of at least 10 MPa which is successful in the use of 20% feldspar at the age of 7 days with a compressive strength of 10.47 MPa and 40 % feldspar at 28 days compressive strength of 10.07 MPa. The use of pure feldspar material as a semenitious can accelerate the setting of mortar time, resulting in an initial setting of 90 minutes for the use of 20% feldspar and 75 minutes for the use of 40% feldspar