Terrazzo Tiles (TT) are considered here as an example of how cement-based building products can affect the environment and that there is an urgent need to overcome (at least partially) the extensive use of cement in the building sector. TT are currently produced using ordinary Portland cement (OPC) based concrete, made of non-renewable raw materials, consuming high energy and water for its production and being responsible of emitting high level of CO2. Generally, to produce 1m3 of mix for current production of Terrazzo Tiles at least 500 kg of cement is required mixed with 1.6 t of aggregates from quarries and 250 kg of water. Construction in the EU accounts for about 50% of all extracted materials and energy consumption, generating about 1/3 of all waste, whereas the production of OPC, accounts for 5-8% of total CO2 emissions. EU directives on saving raw materials, reducing CO2 emissions and landfill, recycling and upcycling waste, improving circular economy, urgently call for studying new and more sustainable building materials. Successful laboratory studies on the use of geopolymers for possible application in the building sector have already demonstrated the effectiveness of these binders which can also contain waste of different types. The positive scientific results at the lab scale, however, is still insufficient to promote the effectiveness of geopolymers at a larger scale. In this study we tested the possibility to pass from the successful lab scale to the industrial implementation, with the help of a company leader in the TT products. TT have been made with the collaboration of the Grandinetti company using alkaline solutions and a combination of:crushed CDW coming from the 2016 earthquake occurred in the Marche region, fly-ash from an electric power plant, rock polishing sludges from local companies. The solid mix is therefore composed of 93% of waste materials, whereas in conventional TT it is composed of 100% of raw materials (75% of raw materials and 25% cement), with a huge saving of raw materials. The geopolymer-based TT so produced satisfied the industrial internal test for quality evaluation. Moreover, the physical properties have been tested and, in particular, the mechanical tests results demonstrated to fall within the limits for the UNI EN 13748-1 norms for TT and in a good agreement with the values for conventional TT. These results are determinant for moving forward to the industrial scale, making the geopolymers products entering the TT market. Moreover, to evaluate the environmental impact of the new products, the Global Warming was calculated as about 184 kg CO2 e/m3 compared to 361 kg CO2 e/m3 of the conventional TT, demonstrating a decrease of 51% in favor of the geopolymer-based ones, which evidence their environmental effectiveness in CO2 reduction.
Geopolymer-based Terrazzo tiles with a high-waste content: stepping forward from the laboratory phase to the industrial scale
Manzi S.;Bignozzi M. C.
2019
Abstract
Terrazzo Tiles (TT) are considered here as an example of how cement-based building products can affect the environment and that there is an urgent need to overcome (at least partially) the extensive use of cement in the building sector. TT are currently produced using ordinary Portland cement (OPC) based concrete, made of non-renewable raw materials, consuming high energy and water for its production and being responsible of emitting high level of CO2. Generally, to produce 1m3 of mix for current production of Terrazzo Tiles at least 500 kg of cement is required mixed with 1.6 t of aggregates from quarries and 250 kg of water. Construction in the EU accounts for about 50% of all extracted materials and energy consumption, generating about 1/3 of all waste, whereas the production of OPC, accounts for 5-8% of total CO2 emissions. EU directives on saving raw materials, reducing CO2 emissions and landfill, recycling and upcycling waste, improving circular economy, urgently call for studying new and more sustainable building materials. Successful laboratory studies on the use of geopolymers for possible application in the building sector have already demonstrated the effectiveness of these binders which can also contain waste of different types. The positive scientific results at the lab scale, however, is still insufficient to promote the effectiveness of geopolymers at a larger scale. In this study we tested the possibility to pass from the successful lab scale to the industrial implementation, with the help of a company leader in the TT products. TT have been made with the collaboration of the Grandinetti company using alkaline solutions and a combination of:crushed CDW coming from the 2016 earthquake occurred in the Marche region, fly-ash from an electric power plant, rock polishing sludges from local companies. The solid mix is therefore composed of 93% of waste materials, whereas in conventional TT it is composed of 100% of raw materials (75% of raw materials and 25% cement), with a huge saving of raw materials. The geopolymer-based TT so produced satisfied the industrial internal test for quality evaluation. Moreover, the physical properties have been tested and, in particular, the mechanical tests results demonstrated to fall within the limits for the UNI EN 13748-1 norms for TT and in a good agreement with the values for conventional TT. These results are determinant for moving forward to the industrial scale, making the geopolymers products entering the TT market. Moreover, to evaluate the environmental impact of the new products, the Global Warming was calculated as about 184 kg CO2 e/m3 compared to 361 kg CO2 e/m3 of the conventional TT, demonstrating a decrease of 51% in favor of the geopolymer-based ones, which evidence their environmental effectiveness in CO2 reduction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
