MECHANICAL PROPERTIES STUDIES OF FLY ASH AND GROUND GRANULATED BLAST FURNACE SLAG BASED GEOPOLYMER CONCRETE

• Main Author: Nur Adi Purnomo, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70232
• Institution: Institut Teknologi Bandung

Many fly ash were available in Indonesia because many industries still using coal as main fuel, because of that, many varieties of fly ash that we can obtain, grade from fly ash depend on combustion temperature and type of coal, from many varieties of fly ash, much of them have low grade, so in this experiment, slag were used to improve geopolymer concrete based on fly ash, so the low grade fly ash can still be used. In this experiment there are 3 type of test, that is fresh concrete, hardened concrete and microstructure test, for fresh concrete experiment there are slump test and setting time test. For slump test, every 25% percentage addition slag into mix design, it can improve workability of geopolymer concrete. For setting time, every addition of slag can decrease setting time, that’s because high content of CaO on slag that were used. In hardened concrete experiment, there are 3 types of test, that is concrete compressive strength test, concrete split tensile strength test and modulus of elasticity test. In these test, every 25% addition of slag can improve strength along with slag addition. From the microstructure test result of F100 (Full fly ash geopolymer concrete) consist of geopolymer gel and CSH gel in crystal shape, because of this, the result of strength test isn’t that good and can’t obtain requirement for structural concrete, but if we add 25% slag into mix design, geopolymer gel and CSH gel that was crystal shaped and doesn’t bond to each other can become more compact and homogeneous, also this slag addition can reduce crack that appear in geopolymer concrete