EFFECT OF CURING TIME AND LIQUID ALKALINE ACTIVATORS ON COMPRESSIVE STRENGTH DEVELOPMENT OF FLY ASH AND BAMBOO LEAF ASH-BASED GEOPOLYMER CONCRETE

Substitute materials are used to modify the properties and characteristics of concrete, for example, to increase strength and improve performance (workability) in concrete. Waste materials from the environment can be used as a substitute material in the concrete mix. One of the efforts is to utilize bamboo leaf ash. Research on bamboo leaf ash as a basic ingredient with sodium hydroxide and sodium silicate added as activators was carried out to determine the characteristics of each parameter on the compressive strength of geopolymer concrete. The method used in this research is an experimental method of conducting laboratory tests using a cylindrical mould measuring 5 cm x 10 cm. The number of cylindrical specimens made was 81, with three molar variations, namely 10, 12, and 14 M. The tests were carried out at the ages of 3, 7, and 28 days. Based on the results of laboratory research, it was shown that geopolymer concrete made from fly ash and bamboo leaf ash had a compressive strength that met the initial planned compressive strength of 20 MPa, and the highest compressive strengths produced from specimens coded CU B3 and CU C3 were 20.892 and 21.911 MPa, respectively. So geopolymer concrete with a mixture composition of 80% fly ash and 20% bamboo leaf ash with a molar variation of 14 M and a mixed composition of 70% fly ash and 30% bamboo leaf ash with a molar variation of 14 M can be used for construction.