Pub Date : 2006-12-01DOI: 10.1080/17747120.2006.9692915
Corentin Aubernon, F. de Larrard
ABSTRACT The paper deals with a new process of road base reinforcement, based upon two beds of used half-tyres, shifted from each other. As in continuous reinforced concrete pavement, shrinkage-induced crack opening should be controlled by the tyres. The principle of this innovative process is described, and analytical cracking calculations are presented, with several hypotheses concerning the type of hydraulic material and the behaviour of the interface between tyres and road-base material. Based upon these calculations, the process appears to be feasible. Tests and deeper theoretical calculations will be necessary in the future. In case of success, the question of industrial process also will have to be addressed.
{"title":"Faisabilité du renforcement d'assises routières à l'aide de pneus usagés","authors":"Corentin Aubernon, F. de Larrard","doi":"10.1080/17747120.2006.9692915","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692915","url":null,"abstract":"ABSTRACT The paper deals with a new process of road base reinforcement, based upon two beds of used half-tyres, shifted from each other. As in continuous reinforced concrete pavement, shrinkage-induced crack opening should be controlled by the tyres. The principle of this innovative process is described, and analytical cracking calculations are presented, with several hypotheses concerning the type of hydraulic material and the behaviour of the interface between tyres and road-base material. Based upon these calculations, the process appears to be feasible. Tests and deeper theoretical calculations will be necessary in the future. In case of success, the question of industrial process also will have to be addressed.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131517027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-12-01DOI: 10.1080/17747120.2006.9692913
Rafat Siddique, A. Noumowé
ABSTRACT This paper presents the results of an experimental investigation carried out to study the effects of replacement of fine aggregate (sand) with high-volumes of Class F fly ash on the strength properties and abrasion resistance. Fine aggregate (sand) was replaced with three percentages (35%, 45%, and 55%) with Class F fly ash by mass. Tests were performed for fresh concrete properties, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and abrasion resistance (depth of wear). Test results indicated that replacement of fine aggregate with high volumes of Class F fly ash enhanced the 28-day compressive strength by 25 to 41%, splitting tensile strength by 12 to 21%, flexural strength by 14 to 17%, and modulus of elasticity by 18 to 23% depending upon the fly ash content, and showed continuous improvement in strength properties. Inclusion of fly ash as fine aggregate replacement significantly improved the abrasion resistance on the concrete at all ages. Relationship between abrasion resistance with that of compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity is also presented.
{"title":"Résistances mécaniques et abrasion de bétons de cendres volantes","authors":"Rafat Siddique, A. Noumowé","doi":"10.1080/17747120.2006.9692913","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692913","url":null,"abstract":"ABSTRACT This paper presents the results of an experimental investigation carried out to study the effects of replacement of fine aggregate (sand) with high-volumes of Class F fly ash on the strength properties and abrasion resistance. Fine aggregate (sand) was replaced with three percentages (35%, 45%, and 55%) with Class F fly ash by mass. Tests were performed for fresh concrete properties, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and abrasion resistance (depth of wear). Test results indicated that replacement of fine aggregate with high volumes of Class F fly ash enhanced the 28-day compressive strength by 25 to 41%, splitting tensile strength by 12 to 21%, flexural strength by 14 to 17%, and modulus of elasticity by 18 to 23% depending upon the fly ash content, and showed continuous improvement in strength properties. Inclusion of fly ash as fine aggregate replacement significantly improved the abrasion resistance on the concrete at all ages. Relationship between abrasion resistance with that of compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity is also presented.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114298583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-12-01DOI: 10.1080/17747120.2006.9692912
Mulumba Kanema, A. Noumowé, Jean-Louis Gallias, R. Cabrillac
ABSTRACT The present study consisted in subjecting five formulations of concrete, containing an identical volume of aggregates and presenting a variable water/cement ratio, to four heating-cooling cycles whose maximum temperatures were fixed at 150, 300, 450, and 600°C. Measurements of compressive strength, tensile strength, modulus of elasticity and gas permeability were then carried out on cylindrical specimens before and after heating. The results made it possible to determine the influence of certain parameters of the concrete formulation on the residual properties, the dehydration of the cementing matrix, the evolution of the permeability and the thermal stability when concrete is subjected to high temperature.
{"title":"Propriétés mécaniques et perméabilités résiduelles de bétons exposés à une tempérapture élevée","authors":"Mulumba Kanema, A. Noumowé, Jean-Louis Gallias, R. Cabrillac","doi":"10.1080/17747120.2006.9692912","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692912","url":null,"abstract":"ABSTRACT The present study consisted in subjecting five formulations of concrete, containing an identical volume of aggregates and presenting a variable water/cement ratio, to four heating-cooling cycles whose maximum temperatures were fixed at 150, 300, 450, and 600°C. Measurements of compressive strength, tensile strength, modulus of elasticity and gas permeability were then carried out on cylindrical specimens before and after heating. The results made it possible to determine the influence of certain parameters of the concrete formulation on the residual properties, the dehydration of the cementing matrix, the evolution of the permeability and the thermal stability when concrete is subjected to high temperature.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129844152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692910
C. Perlot, G. Ballivy, M. Carcassès, X. Bourbon
ABSTRACT Usually, cementitious matrix decalcifications are accelerated by application of concentration gradients. The environmental permeameter presented in this item could originally be used as dynamical degradation process. The appliance of an external physical field of stresses (temperature and pressure) amplifies degradation. The influence of experimental parameters on the water permeability of a mortar was observed: temperature varied from 20 to 80°C and pressure drop was augmented from 2MPa to 10MPa Temperature seems to be the main prejudicial parameter, because of the mechanical effects induced on microstructure combined with hydrates chemicals equilibrium modification.
{"title":"The environmental permeameter","authors":"C. Perlot, G. Ballivy, M. Carcassès, X. Bourbon","doi":"10.1080/17747120.2006.9692910","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692910","url":null,"abstract":"ABSTRACT Usually, cementitious matrix decalcifications are accelerated by application of concentration gradients. The environmental permeameter presented in this item could originally be used as dynamical degradation process. The appliance of an external physical field of stresses (temperature and pressure) amplifies degradation. The influence of experimental parameters on the water permeability of a mortar was observed: temperature varied from 20 to 80°C and pressure drop was augmented from 2MPa to 10MPa Temperature seems to be the main prejudicial parameter, because of the mechanical effects induced on microstructure combined with hydrates chemicals equilibrium modification.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"294 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122305581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692909
L. Lacarrière, A. Sellier, X. Bourbon
ABSTRACT A rheological model with orthotropic short-time and long-time damage is developed in order to model leached concrete behaviour. Coupling with calcium leaching is obtained by affine attenuation of model parameters according to a microhardness profile measured on leached cement pastes. Calibration shows that most model parameters managing mechanical behaviour have the microhardness law as their attenuation law.
{"title":"Concrete mechanical behaviour and calcium leaching weak coupling","authors":"L. Lacarrière, A. Sellier, X. Bourbon","doi":"10.1080/17747120.2006.9692909","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692909","url":null,"abstract":"ABSTRACT A rheological model with orthotropic short-time and long-time damage is developed in order to model leached concrete behaviour. Coupling with calcium leaching is obtained by affine attenuation of model parameters according to a microhardness profile measured on leached cement pastes. Calibration shows that most model parameters managing mechanical behaviour have the microhardness law as their attenuation law.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130716475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692911
A. Ponter, C. Barenghi, Y. Sergeev, W. Schiehlen
{"title":"ADVANCED SCHOOLS 2007 AT INTERNATIONAL CENTRE FOR MECHANICAL SCIENCES (CISM)","authors":"A. Ponter, C. Barenghi, Y. Sergeev, W. Schiehlen","doi":"10.1080/17747120.2006.9692911","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692911","url":null,"abstract":"","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127120655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692907
H. Peycelon, C. Blanc, Caroline Mazoin
ABSTRACT The study of temperature impact on the degradation of cementitious materials has been done with an experimental and a modelling approach. Leaching degradation of CEM I and CEM V cement paste samples were realised for three temperatures (25, 50 and 85°C). These samples have been characterised using several methods (XRD, SEM-EDS and electron microprobe). On other hand the experimental protocol used allows the amount of released species and mainly calcium (Ca2+) and hydroxyls (OH−) to be followed during degradation. The concept of modelling used to describe such a type of degradation and the impact of temperature is explained. The experimental data and the modelling results are compared. Whatever the type of cement-based materials, temperature increases the degradation. This increase is mainly due to transport processes.
{"title":"Long-term behaviour of concrete","authors":"H. Peycelon, C. Blanc, Caroline Mazoin","doi":"10.1080/17747120.2006.9692907","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692907","url":null,"abstract":"ABSTRACT The study of temperature impact on the degradation of cementitious materials has been done with an experimental and a modelling approach. Leaching degradation of CEM I and CEM V cement paste samples were realised for three temperatures (25, 50 and 85°C). These samples have been characterised using several methods (XRD, SEM-EDS and electron microprobe). On other hand the experimental protocol used allows the amount of released species and mainly calcium (Ca2+) and hydroxyls (OH−) to be followed during degradation. The concept of modelling used to describe such a type of degradation and the impact of temperature is explained. The experimental data and the modelling results are compared. Whatever the type of cement-based materials, temperature increases the degradation. This increase is mainly due to transport processes.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123661734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692905
B. Bary, C. Mügler
ABSTRACT We present in this paper a simplified modelling of cementitious material carbonation in unsaturated conditions, constituting an enhanced version of the modelling presented in (Bary et al., 2004). The main improvements consist in the introduction of kinetics for the calcite formation evolving as a function of the degradation state and in the adoption of carbonation mechanisms different for portlandite and the other hydrates. Moreover, the three coupled equations governing the system are now solved with a mixed finite element method in the Cast3m code. Numerical simulations are carried out and compared in terms of carbonation depth with accelerated test data obtained in the workgroup Concrete Engineering Barriers headed by ANDRA. The confrontation between experimental and numerical results is globally satisfactory; however the determination of pH profiles with the modelling remains an open problem when dealing with accelerated experimental procedures.
{"title":"Simplified modelling and numerical simulations of concrete carbonation in unsaturated conditions","authors":"B. Bary, C. Mügler","doi":"10.1080/17747120.2006.9692905","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692905","url":null,"abstract":"ABSTRACT We present in this paper a simplified modelling of cementitious material carbonation in unsaturated conditions, constituting an enhanced version of the modelling presented in (Bary et al., 2004). The main improvements consist in the introduction of kinetics for the calcite formation evolving as a function of the degradation state and in the adoption of carbonation mechanisms different for portlandite and the other hydrates. Moreover, the three coupled equations governing the system are now solved with a mixed finite element method in the Cast3m code. Numerical simulations are carried out and compared in terms of carbonation depth with accelerated test data obtained in the workgroup Concrete Engineering Barriers headed by ANDRA. The confrontation between experimental and numerical results is globally satisfactory; however the determination of pH profiles with the modelling remains an open problem when dealing with accelerated experimental procedures.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132920704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1080/17747120.2006.9692908
P. Le Bescop, Christine Solet
ABSTRACT Materials based on Portland cement react chemically with solutions containing sulphates, even at very low concentrations. The originality of the work described in this paper is to have characterised the kinetics of evolution of mineralogy and solution-material chemical exchanges, for a concentration 10.10−3 mol/L of sulphate, representative of underground conditions, which is a deep geological site made up of argillite. Under these chemical conditions which are maintained as constant as possible at the laboratory scale, the main experimental fact established is the precipitation of gypsum in the damaged zone for two cements with very different C3A contents, despite the low sulphate concentration of the aggressive solution. The gypsum forms immediately behind the dissolution front of portlandite, which itself spreads towards the core of the material at a rate of 0.15 mm.d−0.5. The amplitude of the precipitation of secondary ettringite is consistent with the C3A content of the cement. However, such mineralogical changes did not cause macroscopic alteration.
{"title":"External sulphate attack by ground water","authors":"P. Le Bescop, Christine Solet","doi":"10.1080/17747120.2006.9692908","DOIUrl":"https://doi.org/10.1080/17747120.2006.9692908","url":null,"abstract":"ABSTRACT Materials based on Portland cement react chemically with solutions containing sulphates, even at very low concentrations. The originality of the work described in this paper is to have characterised the kinetics of evolution of mineralogy and solution-material chemical exchanges, for a concentration 10.10−3 mol/L of sulphate, representative of underground conditions, which is a deep geological site made up of argillite. Under these chemical conditions which are maintained as constant as possible at the laboratory scale, the main experimental fact established is the precipitation of gypsum in the damaged zone for two cements with very different C3A contents, despite the low sulphate concentration of the aggressive solution. The gypsum forms immediately behind the dissolution front of portlandite, which itself spreads towards the core of the material at a rate of 0.15 mm.d−0.5. The amplitude of the precipitation of secondary ettringite is consistent with the C3A content of the cement. However, such mineralogical changes did not cause macroscopic alteration.","PeriodicalId":368904,"journal":{"name":"Revue Européenne de Génie Civil","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117312341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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