Experimental Study on The Effect of Additives in Geopolymer’s Kinetic Formation

Geopolymer is a novel material produced from the reaction between silica and alumina as the main raw material with an alkaline solution as an activator to the process so called as geopolymerization process. On top of that, most of the raw materials used in geopolymerization especially for the aluminosilicate materials are taken from the waste product such as fly ash, slag, volcanic ashes and wastewater from industry. Recently, there is an initiative in utilizing waste product from agricultural waste such as palm oil fuel ash (POFA), microwave incinerated rice husk ash (MIRHA) and sugarcane bagasse ash (SCBA) as the new raw materials for geopolymerization due to high composition of silica and fairly composition of alumina and other minerals. However, in geopolymer’s field of study, there is a lack of initiative in investigate the effects of setting time for the geopolymer to solidify with the manipulation of some important parameters and explained it by using Avrami’s Kinetic Theory and presented the concept connected to the nucleation of new crystal particles and growth rate of crystal particles into spherical shaped. Basically, this project is to determine the effect of additives in geopolymer’s kinetic formation. The manipulation of parameter in this study is the manipulation of the composition of the main aluminosilicate material. Tentatively, the main raw aluminosilicate material for this project is fly ash Class F with some additional percentage of agricultural waste ashes (POFA, RHA and SCBA) as the additives. Furthermore, this project also focuses on the growth of crystal in geopolymerization and explained it by using Avrami’s Kinetic Theory. From the sample characterization study in literature review, it is highly noticed that the amount of silica composition in the additives samples are the highest and fairly composition of alumina and other minerals are detected in the samples. From the experimental result, the increase composition of silica in the starting material of the geopolymerization hindered the time to solidify. Based on the Avrami’s Kinetic Theory, the transformation form of crystal in the geopolymerization process features two and three dimensional structures while some samples exhibits the existence of secondary nucleation in geopolymer’s growth