IO, Surabaya – With the rapid pace of modernization and the ever-increasing demand for concrete, the higher the CO2 levels generated by Portland Pozzoland Cement (PPC) as the main material for concrete. In response to this issue, four students from the Tenth of November Institute of Technology (Institut Teknologi Sepuluh Nopember – “ITS”) created an innovation by using ground common paddy field snail shells and powdered natural limestone in their own concrete mix.
Thanks to their innovation, the team of students from ITS’ Civil Infrastructure Engineering Department won three awards in the 2018 Kaohsiung International Invention and Design Expo (KIDE) in Taiwan in early December. Organized by the World Invention Intellectual Property Associations (WIIPA), more than 300 contestants from 26 countries participated. The competition, which started in 2013, is a prestigious forum that highlights the participants’ sensitivity towards the environment by showcasing their original and practical ideas.
Ifon Robi Kurniadi, Ilham Pradana Kusuma, Aditya Rachmad Andriyono, and Mohamad Ilham Fahmi are ITS’ delegates, the PERFE-CT Team. They are one of the 5 teams representing Indonesia in this prestigious international event.
Mohamad Ilham explained his team’s work by stating that one of the reasons Indonesia’s low agricultural productivity despite its 8 million hectares dedicated field is that there are many pests that damage the crops. One of these is the common paddy field snails (Bellamya javanica). Common paddy field snails have a high potential of damaging rice plants. “Common paddy field snails are polyphagous herbivores: they grow and reproduce very rapidly, and they adapt very easily to the environment,” he said.
Ilham further stated that the innovation is based on the fact that Indonesia has abundant local materials, but they are never properly used. Furthermore, common paddy field snail shells have a high concentration of CaCO3 (calcium carbonate), which reacts really well with cement as the main material for making concrete. “We decided to use common paddy field snail shells, because only the meat is used for generations, while the shells are just dumped unused,” he said.
Team Captain Ifon Robi stated that Indonesia has an abundance of natural limestone, especially in East Java province. However, nearly all of the regions blessed with natural limestone do not make optimal use of it, despite its many uses for production, especially for concrete mixes. “Natural limestone reacts well with cement in concrete mixes,” Ifon said.
Furthermore, current PPC production is 2.8 billion tons per annum for producing concrete mixes. It contributes 2%-6% of human-generated CO2 emission, and this amount is predicted to continue increasing. In the production of concrete, pozzolanic is a mixture in the PPC. In order to reduce PPC use, the PERFE-CT Team replaces it with ground snail shells and powdered natural limestone. “Other than being able to replace pozzolanic and reduce environmental damage, this organic local material is also able to reduce waste and improve the local economy if developed properly,” he said.
Ilham stated that the PERFE-CT Team has tried a number of stress load tests using variable material proportions. The test involves several variables using PPC cement, ground snail shells, and powdered natural limestone. Some stress load tests for the concrete generated are: 47.13 MPa; 42.20 Mpa, and 47.64 MPa. The test uses a control mix that uses 100% PPC cement and a 50.17 MPa. “The biggest strength at 47.64 MPa stress load is obtained with a proportion of 80% PPC cement, 10% ground snail shells, and 10% natural limestone,” he said.
Thanks to this original and pure innovation, the concept developed under Ridho Bayuaji, S.T., M.T., Ph.D. earned three awards in the 2018 KIDE: 2018 Kaohsiung International Invention & Design Expo Gold Medal, Award of Excellence from Toronto Canada International Society of Innovation & Advanced Skill, and Excellent Gold Medal from Highly Innovative Unique Foundation of the Kingdom of Saudi Arabia. The concept of using ground common paddy field snail shells and powdered natural limestone in the concrete mix is considered to be a great solution in reducing existing environmental problems (emission and waste) and improving local economy by making use of local materials.
(ITS PR Dept.)