The EU directive 2010/31/EU – sets goals to reduce CO2 emission levels by 20% until year 2020. As... more The EU directive 2010/31/EU – sets goals to reduce CO2 emission levels by 20% until year 2020. As primary energy for households and construction industry both are among the largest manufacturers of CO2, a building material that can positively impact both these industries is topical. A lime-hemp concrete (LHC) is a material with negative CO2 balance, but to achieve the goals set in EU directive a more industrialized product, that can also be used in insulation of existing buildings is needed, so methods of LHC slab and block manufacture are tested in this paper. Eight different types of hemp shives are taken and twelve LHC mixes are prepared to assess the importance of hemp granulometrical distribution. To measure the effect of different preparation techniques mixes in two different mixers – gravity and forced action – were prepared to test the superiority of the latter as it is widely used in LHC production. Also different drying methods – natural, forced with temperature at various...
IOP Conference Series: Materials Science and Engineering, 2019
Foamed concrete has been known as a building material for nearly 100 years. In the beginning, it ... more Foamed concrete has been known as a building material for nearly 100 years. In the beginning, it was used as an insulation material with very low density. Since then there have been attempts to make this material more load-bearing and structural. In present-day foamed concrete is being used in soil reinforcement, building blocks and in other sorts of building applications [1]. Another innovative material - the geopolymer concrete has been around only for 40 years. It is being used in buildings and infrastructures objects such as railroads, reservoirs, and houses and others. The main benefit of the geopolymer is that it is green material that is partially made by utilizing waste products. The geopolymer manufacturing carbon footprint is 2 times less than the Portland cement carbon footprint. Another way to reduce Portland cement carbon footprint is to reuse old cement. In the past few decades, there has been a considerable amount of researches regarding the partial replacement of cem...
High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high ... more High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high temperature. Although the exact causes that lead to spalling are still being debated, moisture transport during heating plays an important role in all proposed mechanisms. In this study, slabs made of high-performance, low water-to-binder ratio mortars with addition of superabsorbent polymers (SAP) and polypropylene fibers (PP) were heated from one side on a temperature-controlled plate up to 550 °C. A combination of measurements was performed simultaneously on the same sample: moisture profiles via neutron radiography, temperature profiles with embedded thermocouples and pore pressure evolution with embedded pressure sensors. Spalling occurred in the sample with SAP, where sharp profiles of moisture and temperature were observed. No spalling occurred when PP-fibers were introduced in addition to SAP. The experimental procedure described here is essential for developing and verifying num...
The EU directive 2010/31/EU – sets goals to reduce CO2 emission levels by 20% until year 2020. As... more The EU directive 2010/31/EU – sets goals to reduce CO2 emission levels by 20% until year 2020. As primary energy for households and construction industry both are among the largest manufacturers of CO2, a building material that can positively impact both these industries is topical. A lime-hemp concrete (LHC) is a material with negative CO2 balance, but to achieve the goals set in EU directive a more industrialized product, that can also be used in insulation of existing buildings is needed, so methods of LHC slab and block manufacture are tested in this paper. Eight different types of hemp shives are taken and twelve LHC mixes are prepared to assess the importance of hemp granulometrical distribution. To measure the effect of different preparation techniques mixes in two different mixers – gravity and forced action – were prepared to test the superiority of the latter as it is widely used in LHC production. Also different drying methods – natural, forced with temperature at various...
IOP Conference Series: Materials Science and Engineering, 2019
Foamed concrete has been known as a building material for nearly 100 years. In the beginning, it ... more Foamed concrete has been known as a building material for nearly 100 years. In the beginning, it was used as an insulation material with very low density. Since then there have been attempts to make this material more load-bearing and structural. In present-day foamed concrete is being used in soil reinforcement, building blocks and in other sorts of building applications [1]. Another innovative material - the geopolymer concrete has been around only for 40 years. It is being used in buildings and infrastructures objects such as railroads, reservoirs, and houses and others. The main benefit of the geopolymer is that it is green material that is partially made by utilizing waste products. The geopolymer manufacturing carbon footprint is 2 times less than the Portland cement carbon footprint. Another way to reduce Portland cement carbon footprint is to reuse old cement. In the past few decades, there has been a considerable amount of researches regarding the partial replacement of cem...
High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high ... more High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high temperature. Although the exact causes that lead to spalling are still being debated, moisture transport during heating plays an important role in all proposed mechanisms. In this study, slabs made of high-performance, low water-to-binder ratio mortars with addition of superabsorbent polymers (SAP) and polypropylene fibers (PP) were heated from one side on a temperature-controlled plate up to 550 °C. A combination of measurements was performed simultaneously on the same sample: moisture profiles via neutron radiography, temperature profiles with embedded thermocouples and pore pressure evolution with embedded pressure sensors. Spalling occurred in the sample with SAP, where sharp profiles of moisture and temperature were observed. No spalling occurred when PP-fibers were introduced in addition to SAP. The experimental procedure described here is essential for developing and verifying num...
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Papers by G. Sahmenko