Erick Ringot | Université Paul Sabatier de Toulouse (original) (raw)
Papers by Erick Ringot
Cement and Concrete Research, 1988
ABSTRACT The stereological method of total projection was practically not applied yet because of ... more ABSTRACT The stereological method of total projection was practically not applied yet because of the difficulty to use it manually. Yet, determinist, it is more precise than the oriented secants technique which is statistic. The author shows how it may be applied to the study of microcracking in concrete, providing its computerization.
Revue française de génie civil, 2000
In the first part, the definition and the methods for estimating the coefficient of activity of a... more In the first part, the definition and the methods for estimating the coefficient of activity of a mineral filler are presented. The calculation relies on predictive laws of strength, here Bolomey's and Feret's laws. In the second part, experimental results concerning the strength of mortars allow us to calculate the coefficient of activity of a fly ash. It is shown that it is not realistic to characterise the activity of the fly ash by a unique coefficient because the strength of mortars is not accordant with a linear law of the substitution ratio. Therefore, it is necessary to evaluate the coefficient of activity as a function of the substitution ratio.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 22, 2018
Presentation d'une methode d'investigation evitant la dessiccation, methode dite de simpl... more Presentation d'une methode d'investigation evitant la dessiccation, methode dite de simple replique, par duplication de la surface etudiee sur un film de bioden, permettant l'observation par microscope electronique a balayage (1000 angstrom). etude du beton a 28 jours de conservation en chambre humide. Methodes stereologiques de quantification des reseaux microfissuraux (automatisation permettant saisie et analyse). etude de l'evolution de la microfissuration sous charge, reliant degre de reversibilite et surface specifique de microfissuration (notion de "picofissuration")
Cement & Concrete Composites, Apr 1, 2001
This paper deals with the techniques of characterisation of cracks and microcracks in concrete an... more This paper deals with the techniques of characterisation of cracks and microcracks in concrete and mortars. It gives an overall view of the methods of observation in relation with image analysis. Image analysis is a useful tool to extract crack patterns from samples of concrete, since many ®elds are necessary to be studied at high magni®cations. An analysis of the procedures and of the provided 2-D data is proposed. The parameters of damage characterisation are listed and discussed. Improvements and ways of research are suggested, mainly to extend 2-D results to 3-D space by means of crack-pattern modelling.
Health and environment, 2019
Indoor air is contaminated by numerous pollutants, which impact human health, comfort and product... more Indoor air is contaminated by numerous pollutants, which impact human health, comfort and productivity. These pollutants have various indoor sources such as building materials, furniture, combustion appliances or tobacco smoke. However, the pollution also comes from outside. In urban area, nitrogen oxides (NO x) emitted into the atmosphere can reach alarming levels. These traffic-related pollutants, which seriously impact the global environment and human health, can infiltrate inside buildings. Therefore, limiting the amount of breathable NO x in outdoor and indoor environments is an important priority for the modern society. The photocatalytic process has attracted particular attention in the last two decades and has proved to be efficient to reduce the concentration of NO x. However, further work has to be conducted to assess its efficiency in real indoor environments. The purpose of this paper was to report on the indoor air quality in an open space office in Manchester, UK. Focus was made on nitric oxide (NO) and nitrogen dioxide (NO 2). The indoor concentrations of both gases were monitored from 14 January 2019 to 7 April 2019. During this period, a photocatalytic coating was applied to a part of the indoor wall. The influence of this coating on the level of NO x was assessed by comparing the indoor concentrations before and after the application. An attention was paid to the correlation between outdoor and indoor pollution and to the effect of other parameters such as temperature, humidity, pressure and ozone (O 3) concentration. The results showed that the photocatalytic process led to a decrease in the NO x concentration. The likelihood to find concentrations above 35 ppb for NO and 7.5 ppb for NO 2 was clearly reduced after the coating application.
Cement and Concrete Research, Nov 1, 1988
ABSTRACT
International journal of environmental impacts, Nov 29, 2019
In spite of their positive role in the framework of circular economy, waste-to-energy processes a... more In spite of their positive role in the framework of circular economy, waste-to-energy processes are responsible for the emissions of a large number of air pollutants. Although this sector has made significant improvements in the air pollution control of primary emissions, the role of other sources (i.e. secondary emissions) has been often neglected. This paper aims at investigating the contributions of primary and secondary emissions expected from a waste gasification plant that is planned for the construction in an Alpine valley. The results from this analysis show that secondary emissions would play a significant role in the overall emissive footprint of the plant, contributing to 29% and 10%, respectively, of the overall emissions of dusts and total organic carbon. In the light of such results, secondary emissions would require an appropriate monitoring approach, which should complement the existing monitoring protocols for primary emissions.
Chemical Engineering Journal, Mar 1, 2021
Almost real-life" experiments of abatement of a pollutant, actually nitrogen monoxide, were carri... more Almost real-life" experiments of abatement of a pollutant, actually nitrogen monoxide, were carried out in a 10-m 3 chamber, the walls of which were covered with plasterboard samples, themselves coated with a photocatalytic dispersion. The experimental protocol consisted in first injecting NO polluted air into the chamber to a certain level, then maintaining a steady level of pollution by tuning the flow rate to balance the leaks and, finally, illuminating the chamber. In a first stage of analysis, a three-flow (injection, leakage and renewal flows) model was used in order to characterize the leakage flow rate. This model was based on the difference of NO concentration between the interior and the exterior rather than on a pressure difference. A two-parameter empirical law was specially formulated for this purpose. In a second stage, the photocatalytic phenomenon was described by a four-flow model completing the previous one, the fourth flow being associated with the photocatalytic oxidation of NO. This flow was described by a rate law derived from the Langmuir-Hinshelwood (L-H) law, which was generalized to the experimental chamber. The parameters (adsorption constant) and (abatement kinetics constant) of the rate law were identified using a standardized lab-scale reactor. The equations, integrated by finite differences, fitted the experimental results correctly. The "diffusive zone thickness" was introduced as the thickness of the air layer potentially concerned by the photocatalysis and was quantified. This first attempt to model photocatalysis on a large scale was promising. However, further research work is needed to enable the model to take more parameters into account.
Advances in Cement Research, Oct 1, 2009
This study aimed to evaluate the effectiveness of a mechanism responsible for the mitigation of e... more This study aimed to evaluate the effectiveness of a mechanism responsible for the mitigation of expansion when reactive aggregate powders (RAP) were used in concrete containing the same reactive aggregate. In the first part, it was shown that RAP were efficient in reducing the expansion of concrete by 35 to 95%. The most efficient powders were those coming from aggregates having high active silica contents (glass, opal). Powders of siliceous limestone were less effective. In a second part, experimental evidence of the pozzolanic activity of RAP was obtained. It was shown that RAP were similar to pozzolan, since they consumed lime and produce calciumsilicate-hydrate (C-S-H) having a lower calcium/silica (C/S) ratio than normal C-S-H. The third part showed experimentally that these low C/S C-S-H could increase the redistribution of alkalis of the pore solution, thus reducing the alkalinity of the pore solution to a level that was sufficiently low to limit the attack of coarser reactive aggregates. In the final part, numerical simulations using a modified version of the hydration model CEMHYD3D were carried out to support this assumption.
Materials and Structures, Oct 1, 1999
Cement and Concrete Research, May 1, 1987
... Sc. Paris t. 275 (1972), p. 1467. B. Perrin, JC Maso, J. Farran and R. Javelas, Existence d&a... more ... Sc. Paris t. 275 (1972), p. 1467. B. Perrin, JC Maso, J. Farran and R. Javelas, Existence d'une auréole de transition entre les granulats d'un mortier ou d'un béton et la masse de la pâte de ciment hydraté. Conséquences sur les propriétés mécaniques, CR Ac. Sc. ...
MRS Proceedings, 1994
Fly ash from power stations is used as concrete additive to improve strength and durability. Surp... more Fly ash from power stations is used as concrete additive to improve strength and durability. Surprisingly, studies of ashes of identical mineralogical composition from two different places have reported different results in terms of the rheological properties of the fresh material. The viscosity of the pastes made from these different fly ashes seems to be linked to the proportion of spherical and smooth-shaped grains found in them. A quantitative image analysis was carried out to characterize the shape of the grains of these two ashes from different geographical origins. The main result proves that the higher the glassy particle content of the fly ash, the more the hydraulic matrix is fluid.
Advanced Powder Technology, Mar 1, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Jul 22, 2018
HAL (Le Centre pour la Communication Scientifique Directe), Oct 10, 2017
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), Jul 2, 2017
The aim of this paper is to assess the degradation of formaldehyde using various coatings, includ... more The aim of this paper is to assess the degradation of formaldehyde using various coatings, including photocatalytic dispersion. The experiments were conducted at a laboratory scale in a standardized photoreactor based on the procedure described in the ISO 22197-4 standard. Various illuminations conditions were explored: UV and visible light. The dispersions tested were applied to common building materials using a coating method. The abatement values were determined by high performance liquid chromatography according to ISO 16000-3 standard. Results showed that parameters such as nature of substrate, type of dispersion and product layer thickness on surface played an important role. Moreover, formaldehyde adsorption on substrate was observed. This phenomenon was far from being negligible and contributed to decrease formaldehyde concentration. Limiting the amount of formaldehyde in indoor environment is a necessary priority for the modern society as this gas known as being carcinogen diminishes the life quality of occupants and poses serious health risks.
Nanomaterials, Dec 7, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Cement and Concrete Research, 1988
ABSTRACT The stereological method of total projection was practically not applied yet because of ... more ABSTRACT The stereological method of total projection was practically not applied yet because of the difficulty to use it manually. Yet, determinist, it is more precise than the oriented secants technique which is statistic. The author shows how it may be applied to the study of microcracking in concrete, providing its computerization.
Revue française de génie civil, 2000
In the first part, the definition and the methods for estimating the coefficient of activity of a... more In the first part, the definition and the methods for estimating the coefficient of activity of a mineral filler are presented. The calculation relies on predictive laws of strength, here Bolomey's and Feret's laws. In the second part, experimental results concerning the strength of mortars allow us to calculate the coefficient of activity of a fly ash. It is shown that it is not realistic to characterise the activity of the fly ash by a unique coefficient because the strength of mortars is not accordant with a linear law of the substitution ratio. Therefore, it is necessary to evaluate the coefficient of activity as a function of the substitution ratio.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 22, 2018
Presentation d'une methode d'investigation evitant la dessiccation, methode dite de simpl... more Presentation d'une methode d'investigation evitant la dessiccation, methode dite de simple replique, par duplication de la surface etudiee sur un film de bioden, permettant l'observation par microscope electronique a balayage (1000 angstrom). etude du beton a 28 jours de conservation en chambre humide. Methodes stereologiques de quantification des reseaux microfissuraux (automatisation permettant saisie et analyse). etude de l'evolution de la microfissuration sous charge, reliant degre de reversibilite et surface specifique de microfissuration (notion de "picofissuration")
Cement & Concrete Composites, Apr 1, 2001
This paper deals with the techniques of characterisation of cracks and microcracks in concrete an... more This paper deals with the techniques of characterisation of cracks and microcracks in concrete and mortars. It gives an overall view of the methods of observation in relation with image analysis. Image analysis is a useful tool to extract crack patterns from samples of concrete, since many ®elds are necessary to be studied at high magni®cations. An analysis of the procedures and of the provided 2-D data is proposed. The parameters of damage characterisation are listed and discussed. Improvements and ways of research are suggested, mainly to extend 2-D results to 3-D space by means of crack-pattern modelling.
Health and environment, 2019
Indoor air is contaminated by numerous pollutants, which impact human health, comfort and product... more Indoor air is contaminated by numerous pollutants, which impact human health, comfort and productivity. These pollutants have various indoor sources such as building materials, furniture, combustion appliances or tobacco smoke. However, the pollution also comes from outside. In urban area, nitrogen oxides (NO x) emitted into the atmosphere can reach alarming levels. These traffic-related pollutants, which seriously impact the global environment and human health, can infiltrate inside buildings. Therefore, limiting the amount of breathable NO x in outdoor and indoor environments is an important priority for the modern society. The photocatalytic process has attracted particular attention in the last two decades and has proved to be efficient to reduce the concentration of NO x. However, further work has to be conducted to assess its efficiency in real indoor environments. The purpose of this paper was to report on the indoor air quality in an open space office in Manchester, UK. Focus was made on nitric oxide (NO) and nitrogen dioxide (NO 2). The indoor concentrations of both gases were monitored from 14 January 2019 to 7 April 2019. During this period, a photocatalytic coating was applied to a part of the indoor wall. The influence of this coating on the level of NO x was assessed by comparing the indoor concentrations before and after the application. An attention was paid to the correlation between outdoor and indoor pollution and to the effect of other parameters such as temperature, humidity, pressure and ozone (O 3) concentration. The results showed that the photocatalytic process led to a decrease in the NO x concentration. The likelihood to find concentrations above 35 ppb for NO and 7.5 ppb for NO 2 was clearly reduced after the coating application.
Cement and Concrete Research, Nov 1, 1988
ABSTRACT
International journal of environmental impacts, Nov 29, 2019
In spite of their positive role in the framework of circular economy, waste-to-energy processes a... more In spite of their positive role in the framework of circular economy, waste-to-energy processes are responsible for the emissions of a large number of air pollutants. Although this sector has made significant improvements in the air pollution control of primary emissions, the role of other sources (i.e. secondary emissions) has been often neglected. This paper aims at investigating the contributions of primary and secondary emissions expected from a waste gasification plant that is planned for the construction in an Alpine valley. The results from this analysis show that secondary emissions would play a significant role in the overall emissive footprint of the plant, contributing to 29% and 10%, respectively, of the overall emissions of dusts and total organic carbon. In the light of such results, secondary emissions would require an appropriate monitoring approach, which should complement the existing monitoring protocols for primary emissions.
Chemical Engineering Journal, Mar 1, 2021
Almost real-life" experiments of abatement of a pollutant, actually nitrogen monoxide, were carri... more Almost real-life" experiments of abatement of a pollutant, actually nitrogen monoxide, were carried out in a 10-m 3 chamber, the walls of which were covered with plasterboard samples, themselves coated with a photocatalytic dispersion. The experimental protocol consisted in first injecting NO polluted air into the chamber to a certain level, then maintaining a steady level of pollution by tuning the flow rate to balance the leaks and, finally, illuminating the chamber. In a first stage of analysis, a three-flow (injection, leakage and renewal flows) model was used in order to characterize the leakage flow rate. This model was based on the difference of NO concentration between the interior and the exterior rather than on a pressure difference. A two-parameter empirical law was specially formulated for this purpose. In a second stage, the photocatalytic phenomenon was described by a four-flow model completing the previous one, the fourth flow being associated with the photocatalytic oxidation of NO. This flow was described by a rate law derived from the Langmuir-Hinshelwood (L-H) law, which was generalized to the experimental chamber. The parameters (adsorption constant) and (abatement kinetics constant) of the rate law were identified using a standardized lab-scale reactor. The equations, integrated by finite differences, fitted the experimental results correctly. The "diffusive zone thickness" was introduced as the thickness of the air layer potentially concerned by the photocatalysis and was quantified. This first attempt to model photocatalysis on a large scale was promising. However, further research work is needed to enable the model to take more parameters into account.
Advances in Cement Research, Oct 1, 2009
This study aimed to evaluate the effectiveness of a mechanism responsible for the mitigation of e... more This study aimed to evaluate the effectiveness of a mechanism responsible for the mitigation of expansion when reactive aggregate powders (RAP) were used in concrete containing the same reactive aggregate. In the first part, it was shown that RAP were efficient in reducing the expansion of concrete by 35 to 95%. The most efficient powders were those coming from aggregates having high active silica contents (glass, opal). Powders of siliceous limestone were less effective. In a second part, experimental evidence of the pozzolanic activity of RAP was obtained. It was shown that RAP were similar to pozzolan, since they consumed lime and produce calciumsilicate-hydrate (C-S-H) having a lower calcium/silica (C/S) ratio than normal C-S-H. The third part showed experimentally that these low C/S C-S-H could increase the redistribution of alkalis of the pore solution, thus reducing the alkalinity of the pore solution to a level that was sufficiently low to limit the attack of coarser reactive aggregates. In the final part, numerical simulations using a modified version of the hydration model CEMHYD3D were carried out to support this assumption.
Materials and Structures, Oct 1, 1999
Cement and Concrete Research, May 1, 1987
... Sc. Paris t. 275 (1972), p. 1467. B. Perrin, JC Maso, J. Farran and R. Javelas, Existence d&a... more ... Sc. Paris t. 275 (1972), p. 1467. B. Perrin, JC Maso, J. Farran and R. Javelas, Existence d'une auréole de transition entre les granulats d'un mortier ou d'un béton et la masse de la pâte de ciment hydraté. Conséquences sur les propriétés mécaniques, CR Ac. Sc. ...
MRS Proceedings, 1994
Fly ash from power stations is used as concrete additive to improve strength and durability. Surp... more Fly ash from power stations is used as concrete additive to improve strength and durability. Surprisingly, studies of ashes of identical mineralogical composition from two different places have reported different results in terms of the rheological properties of the fresh material. The viscosity of the pastes made from these different fly ashes seems to be linked to the proportion of spherical and smooth-shaped grains found in them. A quantitative image analysis was carried out to characterize the shape of the grains of these two ashes from different geographical origins. The main result proves that the higher the glassy particle content of the fly ash, the more the hydraulic matrix is fluid.
Advanced Powder Technology, Mar 1, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Jul 22, 2018
HAL (Le Centre pour la Communication Scientifique Directe), Oct 10, 2017
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), Jul 2, 2017
The aim of this paper is to assess the degradation of formaldehyde using various coatings, includ... more The aim of this paper is to assess the degradation of formaldehyde using various coatings, including photocatalytic dispersion. The experiments were conducted at a laboratory scale in a standardized photoreactor based on the procedure described in the ISO 22197-4 standard. Various illuminations conditions were explored: UV and visible light. The dispersions tested were applied to common building materials using a coating method. The abatement values were determined by high performance liquid chromatography according to ISO 16000-3 standard. Results showed that parameters such as nature of substrate, type of dispersion and product layer thickness on surface played an important role. Moreover, formaldehyde adsorption on substrate was observed. This phenomenon was far from being negligible and contributed to decrease formaldehyde concentration. Limiting the amount of formaldehyde in indoor environment is a necessary priority for the modern society as this gas known as being carcinogen diminishes the life quality of occupants and poses serious health risks.
Nanomaterials, Dec 7, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY