Displaying items by tag: compressive strength

Lithuania: Scientists at Kaunas University of Technology (KTU) have developed methods to convert discarded textiles into alternative fuels and cement additives to reduce waste. Efforts focus on reducing the clinker content of cement and CO₂ output.

Dr Raimonda Kubiliute of the KTU Faculty of Chemical Technology said “The cement industry, especially clinker firing processes in rotary kilns, contributes significantly to environmental pollution. This is why researchers are actively seeking ways to reduce the amount of conventional cement in cement-based mixtures by replacing it with alternative binders or fillers.”

KTU found that polyester fibre from waste textiles, when added to concrete at 1.5%, increases compressive strength by 15-20% and improves freeze-thaw resistance. Ash from thermal treatment of textiles at 300°C in an inert atmosphere can replace up to 7.5% of ordinary Portland cement and increase strength by up to 16% under curing conditions. The findings are part of the ‘Production of Alternative Fuel from Textile Waste in Energy-Intensive Industries (Textifuel)’ project between KTU and the Lithuanian Energy Institute.

Dr Kubiliute said “This technological solution not only reduces CO₂ emissions during cement production but also provides an innovative and environmentally friendly approach to textile waste management.”

Indonesia: Suvo Strategic Minerals has reported successful laboratory tests in collaboration with Makassar State University (UNM) in Indonesia, transforming nickel slag into a ‘high-strength, low-cost and low-carbon’ cement, according to The Sydney Morning Herald. The trials used slag from PT Huadi Nickel-Alloy Indonesia's operations in South Sulawesi, achieving a compressive strength of 37.5MPa after seven days. The company is now looking to conduct further testing and will provide the results to PT Huadi, with the aim of forming a partnership for the commercialisation of low-carbon cement using nickel slag.

Aaron Bank, executive chair of Suvo Strategic Minerals, said “We are excited to have commenced this workstream in Indonesia testing the byproduct of one of the country’s largest mining companies, with our ultimate goal being to manufacture an environmentally-friendly and low-carbon alternative to Portland cement. Achieving up to 37.5MPa after only seven days is an outstanding first round trial result for the company and could provide an entry into a large industry.”

Nepal: The Nepalese government has implemented new cement regulations specifying the minimum compressive strength of 33MPa. The Republica newspaper has reported that this will follow the 1997 Cement Standard in restricting magnesia (MgO) content to 5% and insoluble residues to 2%. Two higher grades will designate cement with compressive strengths of 44MPa and 55MPa.

The government also introduced regulations governing the compression strength, insulation and density of autoclaved aerated concrete (AAC) blocks.