Estimation of Norwegian Asphalt Surfacing Lifetimes Using Survival Analysis Coupled with Road Spatial Data

Combinations of different factors and their relative importance have a mixed effect on the longevity of pavements, which are essential to be understood to enhance long-term maintenance planning. This study used spatial road data from Norway followed by integrating temporal-spatial and statistical analyses to show a potential approach to estimate the lifetimes of asphalt surfacing. For the statistical part, a stratified Cox proportional hazard model was used to understand the relationship between longevity of surface mixtures and different factors, while avoiding having predefined assumptions rooted in deterministic modeling. In addition, rutting was used as the response variable to determine distress-specific asphalt surfacing lifetimes and to handle censored data. Inclusion of rutting as the response variable showed that the median technical lifetime of asphalt surfacing is about 2\ua0years shorter than that of the maintenance activity records. The results showed the significance of each covariate; however, aggregate nominal maximum size and heavy traffic volume were consistently the significant covariates across the studied traffic classes. In addition, the results were fitted to reference categories in each covariate to show a practical approach to interpret absolute values of lifetimes from a survival table

Novel synthesis method of BaTiO3-nanoparticles - Synthesis of BaTiO3-nanoparticles by spray-pyrolysis of TiO2-nanoparticles dispersed in Ba(NO3)2-solution

Ferroelectric materials are widely used in different technological applications. Lead zirconate titanate (PZT) materials are currently the most used, due to their excellent piezoelectric properties and relatively high operating temperatures. However, due to high lead content and its environmental toxicity, lead-free alternatives are being explored. One such material is barium titanate (BaTiO3). Finding cheap, energy-efficient, and scalable synthesis methods for such materials is necessary to start phasing out PZT in favor of more environmentally friendly alternatives. The particle size of ceramic powders is an important property as many materials exhibit different physical behavior when the particle size is in the nanometer range. Increased material strength, unique optical properties, and increased reactivity are some examples. Several applications of ceramic powders rely on this phenomenon; e.g. increased sintering activity where fine powder is needed to promote densification. This work explores the possibility of synthesizing BaTiO3-nanoparticles through spray pyrolysis of a suspension with TiO2-nanoparticles dispersed in a barium nitrate solution. BaTiO3-nanoparticles with particle size between 50-100 nm were achieved. The importance of suspension stability with regard to phase purity and yield of produced powder was investigated. The results of the powder characterization indicate that complexing the barium-ions with ethylenediaminetetraacetic acid (EDTA) and citric acid (CA) may be necessary to achieve satisfactory stability and stoichiometric control of the suspension. Pellets were produced and the sintering behavior and piezoelectric properties of these pellets were investigated. The piezoelectric properties of the samples are comparable to reported values for BaTiO3 in regards to polarization values, but significantly lower than reported in regards to measured displacement values. The results indicate some contamination or secondary phase formation in the samples. The contamination is believed to originate from either the precursor powders, the spray-pyrolysis equipment or process, or a combination of both. Further work is required to determine the usefulness of the method. The suspension stability must be improved to ensure stoichiometric control during the process. The source of the contamination or secondary phase formation must also be identified and eliminated

Novel synthesis method of BaTiO3-nanoparticles - Synthesis of BaTiO3-nanoparticles by spray-pyrolysis of TiO2-nanoparticles dispersed in Ba(NO3)2-solution

Ferroelectric materials are widely used in different technological applications. Lead zirconate titanate (PZT) materials are currently the most used, due to their excellent piezoelectric properties and relatively high operating temperatures. However, due to high lead content and its environmental toxicity, lead-free alternatives are being explored. One such material is barium titanate (BaTiO3). Finding cheap, energy-efficient, and scalable synthesis methods for such materials is necessary to start phasing out PZT in favor of more environmentally friendly alternatives. The particle size of ceramic powders is an important property as many materials exhibit different physical behavior when the particle size is in the nanometer range. Increased material strength, unique optical properties, and increased reactivity are some examples. Several applications of ceramic powders rely on this phenomenon; e.g. increased sintering activity where fine powder is needed to promote densification. This work explores the possibility of synthesizing BaTiO3-nanoparticles through spray pyrolysis of a suspension with TiO2-nanoparticles dispersed in a barium nitrate solution. BaTiO3-nanoparticles with particle size between 50-100 nm were achieved. The importance of suspension stability with regard to phase purity and yield of produced powder was investigated. The results of the powder characterization indicate that complexing the barium-ions with ethylenediaminetetraacetic acid (EDTA) and citric acid (CA) may be necessary to achieve satisfactory stability and stoichiometric control of the suspension. Pellets were produced and the sintering behavior and piezoelectric properties of these pellets were investigated. The piezoelectric properties of the samples are comparable to reported values for BaTiO3 in regards to polarization values, but significantly lower than reported in regards to measured displacement values. The results indicate some contamination or secondary phase formation in the samples. The contamination is believed to originate from either the precursor powders, the spray-pyrolysis equipment or process, or a combination of both. Further work is required to determine the usefulness of the method. The suspension stability must be improved to ensure stoichiometric control during the process. The source of the contamination or secondary phase formation must also be identified and eliminated

FoU Indre Romsdal. Feltforsøk på Hjerkinn 2010 - sidefriksjon

publishedVersio

Characterization of tire and road wear microplastic particle contamination in a road tunnel: From surface to release

Road pollution is one of the major sources of microplastic particles to the environment. The distribution of tire, polymer-modified bitumen (PMB) and tire and road wear particles (TRWP) in different tunnel compartments were explored: road surface, gully-pots and tunnel wash water. A new method for calculating TRWP using Monte Carlo simulation is presented. The highest concentrations on the surface were in the side bank (tire:13.4 ± 5.67;PMB:9.39 ± 3.96; TRWP:22.9 ± 8.19 mg/m2), comparable to previous studies, and at the tunnel outlet (tire:7.72 ± 11.2; PMB:5.40 ± 7.84; TRWP:11.2 ± 16.2 mg/m2). The concentrations in gully-pots were highest at the inlet (tire:24.7 ± 26.9; PMB:17.3 ± 48.8; TRWP:35.8 ± 38.9 mg/g) and comparable to values previously reported for sedimentation basins. Untreated wash water was comparable to road runoff (tire:38.3 ± 10.5; PMB:26.8 ± 7.33; TRWP:55.3 ± 15.2 mg/L). Sedimentation treatment retained 63% of tire and road wear particles, indicating a need to increase the removal efficiency to prevent these from entering the environment. A strong linear relationship (R2-adj=0.88, p < 0.0001) between total suspended solids (TSS) and tire and road wear rubber was established, suggesting a potential for using TSS as a proxy for estimating rubber loads for monitoring purposes. Future research should focus on a common approach to analysis and calculation of tire, PMB and TRWP and address the uncertainties related to these calculations

Characterization of tire and road wear microplastic particle contamination in a road tunnel: From surface to release

Road pollution is one of the major sources of microplastic particles to the environment. The distribution of tire, polymer-modified bitumen (PMB) and tire and road wear particles (TRWP) in different tunnel compartments were explored: road surface, gully-pots and tunnel wash water. A new method for calculating TRWP using Monte Carlo simulation is presented. The highest concentrations on the surface were in the side bank (tire:13.4 ± 5.67;PMB:9.39 ± 3.96; TRWP:22.9 ± 8.19 mg/m2), comparable to previous studies, and at the tunnel outlet (tire:7.72 ± 11.2; PMB:5.40 ± 7.84; TRWP:11.2 ± 16.2 mg/m2). The concentrations in gully-pots were highest at the inlet (tire:24.7 ± 26.9; PMB:17.3 ± 48.8; TRWP:35.8 ± 38.9 mg/g) and comparable to values previously reported for sedimentation basins. Untreated wash water was comparable to road runoff (tire:38.3 ± 10.5; PMB:26.8 ± 7.33; TRWP:55.3 ± 15.2 mg/L). Sedimentation treatment retained 63% of tire and road wear particles, indicating a need to increase the removal efficiency to prevent these from entering the environment. A strong linear relationship (R2-adj=0.88, p < 0.0001) between total suspended solids (TSS) and tire and road wear rubber was established, suggesting a potential for using TSS as a proxy for estimating rubber loads for monitoring purposes. Future research should focus on a common approach to analysis and calculation of tire, PMB and TRWP and address the uncertainties related to these calculations

Characterization of tire and road wear microplastic particle contamination in a road tunnel: From surface to release

Road pollution is one of the major sources of microplastic particles to the environment. The distribution of tire, polymer-modified bitumen (PMB) and tire and road wear particles (TRWP) in different tunnel compartments were explored: road surface, gully-pots and tunnel wash water. A new method for calculating TRWP using Monte Carlo simulation is presented. The highest concentrations on the surface were in the side bank (tire:13.4 ± 5.67;PMB:9.39 ± 3.96; TRWP:22.9 ± 8.19 mg/m2), comparable to previous studies, and at the tunnel outlet (tire:7.72 ± 11.2; PMB:5.40 ± 7.84; TRWP:11.2 ± 16.2 mg/m2). The concentrations in gully-pots were highest at the inlet (tire:24.7 ± 26.9; PMB:17.3 ± 48.8; TRWP:35.8 ± 38.9 mg/g) and comparable to values previously reported for sedimentation basins. Untreated wash water was comparable to road runoff (tire:38.3 ± 10.5; PMB:26.8 ± 7.33; TRWP:55.3 ± 15.2 mg/L). Sedimentation treatment retained 63% of tire and road wear particles, indicating a need to increase the removal efficiency to prevent these from entering the environment. A strong linear relationship (R2-adj=0.88, p < 0.0001) between total suspended solids (TSS) and tire and road wear rubber was established, suggesting a potential for using TSS as a proxy for estimating rubber loads for monitoring purposes. Future research should focus on a common approach to analysis and calculation of tire, PMB and TRWP and address the uncertainties related to these calculations.publishedVersio