Rice husk ash (RHA) emerges from a readily available agricultural waste: rice husks, a byproduct of rice processing. Burning these husks under controlled conditions generates RHA, which historically posed a disposal challenge. However, research has revealed its high silica content (85-95%), making it a promising material for geopolymerization. This process transforms RHA into a strong and durable binding material with the potential to replace traditional cement.
Rice husk ash (RHA) matters because it offers a solution to two significant ecological challenges: waste management and the environmental impact of the construction industry.
Waste Reduction: RHA utilization transforms readily available agricultural waste into a valuable resource. This reduces the need for landfilling rice husks, which can contaminate soil and water bodies with organic matter and potentially harmful chemicals.
Reduced Carbon Footprint: Cement production, a cornerstone of the construction industry, contributes significantly to greenhouse gas emissions. Utilizing RHA geopolymers instead offers a lower carbon footprint, mitigating the industry’s environmental impact and contributing to climate change mitigation efforts. Potential Fire Resistance: Research suggests RHA geopolymers exhibit improved fire resistance compared to conventional materials. This can potentially enhance building safety and reduce the risk of wildfires spreading, particularly in areas prone to such occurrences.
Shriyam Rai
45 minutes
3/10
Preparation of Materials:
Rice Husk Ash (RHA) and Metakaolin Mixture:
1. Mix 20g of RHA in a bowl of 50g of Metakaolin. Mix thoroughly to achieve optimum distribution of RHA in the bowl.
Alkaline Activator:
Prepare a solution of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) in water.
The molarity of the NaOH solution and the ratio of Na2SiO3 to NaOH can be adjusted according to the desired properties.
Mixing and Casting:
1. Mix the alkali solution with the RHA/Kaolin mixture bowl
2. Mix well and adjust the ratio of the alkali solution and metakaolin content based on the desired consistency (for this batch, the consistency desired was the same as the clay used in the potterbot)
3. Place the mixture in the potterbot tube and prep the machine for extrusion





