A mechanism for the production of ultrafine particles from concrete fracture
| Autor: | Graham R. Johnson, Erik Uhde, E. Rohan Jayaratne, Joel Alroe, Nassib Jabbour, Lidia Morawska, Tunga Salthammer, Prashant Kumar, Ehsan Majd Faghihi, Luke T. Cravigan |
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| Přispěvatelé: | Publica |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
010504 meteorology & atmospheric sciences Health Toxicology and Mutagenesis 010501 environmental sciences Toxicology 01 natural sciences secondary particles Ultrafine particle airborne dust Particle Size Composite material 0105 earth and related environmental sciences Air Pollutants Volatilisation Construction Materials Mechanical Processes Dust General Medicine Pollution ultrafine particles Volume fraction concrete Particulate Matter Particle size Volatilization Volatility (chemistry) urban pollution |
| Zdroj: | Environmental Pollution. 222:175-181 |
| ISSN: | 0269-7491 |
| DOI: | 10.1016/j.envpol.2016.12.059 |
| Popis: | While the crushing of concrete gives rise to large quantities of coarse dust, it is not widely recognized that this process also emits significant quantities of ultrafine particles. These particles impact not just the environments within construction activities but those in entire urban areas. The origin of these ultrafine particles is uncertain, as existing theories do not support their production by mechanical processes. We propose a hypothesis for this observation based on the volatilisation of materials at the concrete fracture interface. The results from this study confirm that mechanical methods can produce ultrafine particles (UFP) from concrete, and that the particles are volatile. The ultrafine mode was only observed during concrete fracture, producing particle size distributions with average count median diameters of 27, 39 and 49 nm for the three tested concrete samples. Further volatility measurements found that the particles were highly volatile, showing between 60 and 95% reduction in the volume fraction remaining by 125 °C. An analysis of the volatile fraction remaining found that different volatile material is responsible for the production of particles between the samples. |
| Databáze: | OpenAIRE |
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