Geopolymer is an aluminosilicate material that can be prepared from thermal activation of solid material containing alumina and silica as precursor and alkali activator solution. The precursor is an eco-friendly material and has a potency to replace Portland cement (cementless material). In this work, cementless geopolymer mortar was prepared by mixing fly ash as main precursors, red mud, and electric arc furnace dust slag, followed by addition of activator solution containing sodium hydroxide solution and waterglass. X-ray diffraction and Fourier transform infra-red spectroscopy demonstrated the formation of albite in geopolymer mortars, indicating that geopolymer mortars have been successfully formed. The best compressive strength of mortars was 72.80 MPa achieved by using fly ash and red mud with NaOH 12M under ambient curing.
Plastic Composite Panel (PCP) is an innovation in the field of materials that uses recycling plastic waste to construct composite cement panels. This material innovation is one of the solutionto answer environmental problems caused by plastic waste. Some previous studies mostly used plastic waste for concrete aggregates. Thus, making this study different from previous studies. The purpose of this study is to make a prototype of a PCP that is environmentally friendly with panel dimensions sample of 100 x 30 x 10 mm thick. The method used is an experimental test using materials in the form of polyethylene terephtalate (PET) from used water bottle and cement waste as well as testing its physical and mechanical properties carried out in the laboratory. Variations in PET used for testing materials are 0- 20%. In addition to mechanical properties, specific gravity and porosity test is carried out. The best results shows that 5% PET addition to cement paste increase the flexutral strength to 4.47 MPa compared to control sample which has 3.26 MPa. Porosity test shows that addition of 10% PET reduce the density of PCP to 63.64% compared to control sample that has 44.44%.
Metakaolin-based porous geopolymer had been successfully developed using aluminum powder by creating bubbles in the structure. These structures were required to mimic the spongy bone thus may be applied as bone substitute materials. It was conducted by adding the aluminum powder in the mixture of Metakaolin (MK) and Alkaline Activator (AA) (NaOH solution and sodium silicate) with ratio 1:1, 1:1,5, 1: 2, 1:2,5 and 1:3 then namely sample A-E respectively. The slurry was then poured into mold 30 x 30 x 30 mm3. Samples were let harden and heated in the oven 80°C for 4 hours prior to demolding. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) were used to observe the morphology of porosity resulted in the samples and to characterize the crystallinity of the samples. The results showed porous metakaolin geopolymer of sample A had the most similarity with the human spongy bone (80-400 µm). Along with an increase in the amount of AA, crystallinity of albite show a decrease of intensity. This study concluded the porous metakaolin geopolymer obtained was potential to be used as a bone substitutes materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.