This page has only limited features, please log in for full access.
The reactivity effect of calcium carbonate, present in ground oyster shells and limestone filler, on the formation of carboaluminate phases in ground granulated blast furnace slag blended cement pastes was reported in this paper. Six different binary and ternary blended cement pastes were prepared using ground granulated blast furnace slag, ground oyster shells and limestone filler with different replacement levels (from 5 to 35%). The carboaluminate formation was assessed and quantified directly using X-ray diffraction (XRD), and indirectly by following the aluminate phase’s reaction (heat flow) and consumed calcium carbonate using Isothermal Calorimetry (IC) and Thermogravimetric Analysis (TGA), respectively. Further, the overall reaction degree calculated based on TGA results and the compressive strength were determined to support the findings obtained. The results revealed that the calcium carbonate present in ground oyster shells is more reactive when compared to that present in limestone filler, where more formed hemi- and monocarboaluminate phases were observed in mixtures containing ground oyster shells. An enhancement in compressive strength and overall reaction degree was observed by adding 5% ground oyster shells as cement replacement.
Walid Deboucha; Nassim Sebaibi; Yassine El Mendili; Aurélie Fabien; U. Alengaram; Nordine Leklou; Mahmoud Hamdadou; Alexandra Bourdot; Stéphanie Gascoin. Reactivity Effect of Calcium Carbonate on the Formation of Carboaluminate Phases in Ground Granulated Blast Furnace Slag Blended Cements. Sustainability 2021, 13, 6504 .
AMA StyleWalid Deboucha, Nassim Sebaibi, Yassine El Mendili, Aurélie Fabien, U. Alengaram, Nordine Leklou, Mahmoud Hamdadou, Alexandra Bourdot, Stéphanie Gascoin. Reactivity Effect of Calcium Carbonate on the Formation of Carboaluminate Phases in Ground Granulated Blast Furnace Slag Blended Cements. Sustainability. 2021; 13 (11):6504.
Chicago/Turabian StyleWalid Deboucha; Nassim Sebaibi; Yassine El Mendili; Aurélie Fabien; U. Alengaram; Nordine Leklou; Mahmoud Hamdadou; Alexandra Bourdot; Stéphanie Gascoin. 2021. "Reactivity Effect of Calcium Carbonate on the Formation of Carboaluminate Phases in Ground Granulated Blast Furnace Slag Blended Cements." Sustainability 13, no. 11: 6504.
The determination of the energy consumption of a building requires the computation of the coupled heat and mass transfers inside the wall. The existing models require the determination of the hygrothermal properties of the materials, and of the boundary and initial conditions, prior to computing numerically the temperature and vapour fluxes and the energy and mass balance of the building. However, the experimental measurements do not give accurate values, yielding a wrong estimation of the energy consumption. In order to determine the influence of the uncertainties on the values of the input parameters of the Kunzel model, we carried out a local sensitivity analysis (LSA) by varying by 5% the hygrothermal properties of the materials, the surface transfer coefficients and the initial conditions. The results of the LSA are treated by means of quartile boxes in order to identifiy the most influent parameters. The LSA is applied to two walls made of highly porous and hygroscopic materials: limestone and hemp concrete. The results show that the surface transfer coefficients and the adsorption isotherm are the most influential parameters. However, the conclusions are slightly different between the two materials, because of differences in the relative importance of transfer phenomena.
Ines Othmen; Philippe Poullain; Nordine Leklou. Sensitivity analysis of the transient heat and moisture transfer in a single layer wall. European Journal of Environmental and Civil Engineering 2018, 24, 2211 -2229.
AMA StyleInes Othmen, Philippe Poullain, Nordine Leklou. Sensitivity analysis of the transient heat and moisture transfer in a single layer wall. European Journal of Environmental and Civil Engineering. 2018; 24 (13):2211-2229.
Chicago/Turabian StyleInes Othmen; Philippe Poullain; Nordine Leklou. 2018. "Sensitivity analysis of the transient heat and moisture transfer in a single layer wall." European Journal of Environmental and Civil Engineering 24, no. 13: 2211-2229.
The hydration degree assessment of slag blended cement pastes with three different replacement levels (10, 20 and 40%) and two finenesses (400 and 500 m2/kg) was investigated. The hydration degree was evaluated by using a modified TG method suggested by Deboucha et al., 2017. This method builds on the activity coefficient concept, which makes it possible to assume the amount of mineral additives that contribute to hydration reactions as well as cement. Results showed that the efficiency of blast furnace slag in developing hydration degree was conditioned by its level of replacement and fineness.
Walid Deboucha; Nordine Leklou; Abdelhafid Khelidj. Hydration degree development of blast furnace slag blended cement pastes using thermogravimetric Analysis (TGA). MATEC Web of Conferences 2018, 163, 04001 .
AMA StyleWalid Deboucha, Nordine Leklou, Abdelhafid Khelidj. Hydration degree development of blast furnace slag blended cement pastes using thermogravimetric Analysis (TGA). MATEC Web of Conferences. 2018; 163 ():04001.
Chicago/Turabian StyleWalid Deboucha; Nordine Leklou; Abdelhafid Khelidj. 2018. "Hydration degree development of blast furnace slag blended cement pastes using thermogravimetric Analysis (TGA)." MATEC Web of Conferences 163, no. : 04001.
Reducing expansion due to Delayed Ettringite Formation (DEF) is becoming an important issue that must be taken into account, when producing heat-cured concrete. Mineral additives used as partial cement replacement should help in achieving the desired aspect. Based on an ongoing experimental program, this research emphasizes on the effect of Blast Furnace Slag (BFS) on the expansion of cement mortars caused by DEF. For this purpose, mortar prisms in which Portland cement was replaced by BFS, with three different replacement levels (10,20 and 40%) and two finenesses degree (400 and 500 m2/kg) were tested in length change, dynamic elasticity modulus and compressive strength over more than 750 days. Results showed that the efficiency of blast furnace slag in controlling expansion related to DEF was conditioned by its levels of replacement.
Walid Deboucha; Nordine Leklou; Abdelhafid Khelidj. Blast Furnace Slag Addition Effects on Delayed Ettringite Formation in Heat-cured Mortars. KSCE Journal of Civil Engineering 2018, 22, 3484 -3490.
AMA StyleWalid Deboucha, Nordine Leklou, Abdelhafid Khelidj. Blast Furnace Slag Addition Effects on Delayed Ettringite Formation in Heat-cured Mortars. KSCE Journal of Civil Engineering. 2018; 22 (9):3484-3490.
Chicago/Turabian StyleWalid Deboucha; Nordine Leklou; Abdelhafid Khelidj. 2018. "Blast Furnace Slag Addition Effects on Delayed Ettringite Formation in Heat-cured Mortars." KSCE Journal of Civil Engineering 22, no. 9: 3484-3490.
The cement manufacturing is the one of the factors that pollutes the atmosphere in the industrial sector. The common way to reduce this pollution is using mineral additives as partial replacement of Portland cement. Particularly, natural pozzolana (NP) is a component in which they can be used to decrease the rate of pollution. The main objective of this experimental work is the study of the effect of substituting cement with natural pozzolana up to 40% on compressive-flexural strength and capillary water absorption of cement mortar. Validation of the results was performed by early age and long term tests. Tests of isothermal calorimetry on paste specimens, and of Mercury intrusion porosimetry on mortar specimens, were performed. The results obtained in the present research showed that the higher dosages of natural pozzolana added could be the principal parameter of such decrease in strength at early and medium term. Further, this increase of incorporated addition has been believed to reduce the capillary water absorption.
Walid Deboucha; Nordine Leklou; Abdelhafid Khelidj; Mohamed N. Oudjit. Natural pozzolana addition effect on compressive strength and capillary water absorption of Mortar. Energy Procedia 2017, 139, 689 -695.
AMA StyleWalid Deboucha, Nordine Leklou, Abdelhafid Khelidj, Mohamed N. Oudjit. Natural pozzolana addition effect on compressive strength and capillary water absorption of Mortar. Energy Procedia. 2017; 139 ():689-695.
Chicago/Turabian StyleWalid Deboucha; Nordine Leklou; Abdelhafid Khelidj; Mohamed N. Oudjit. 2017. "Natural pozzolana addition effect on compressive strength and capillary water absorption of Mortar." Energy Procedia 139, no. : 689-695.
Walid Deboucha; Nordine Leklou; Abdelhafid Khelidj; Mohamed N Oudjit. Hydration development of mineral additives blended cement using thermogravimetric analysis (TGA): Methodology of calculating the degree of hydration. Construction and Building Materials 2017, 146, 687 -701.
AMA StyleWalid Deboucha, Nordine Leklou, Abdelhafid Khelidj, Mohamed N Oudjit. Hydration development of mineral additives blended cement using thermogravimetric analysis (TGA): Methodology of calculating the degree of hydration. Construction and Building Materials. 2017; 146 ():687-701.
Chicago/Turabian StyleWalid Deboucha; Nordine Leklou; Abdelhafid Khelidj; Mohamed N Oudjit. 2017. "Hydration development of mineral additives blended cement using thermogravimetric analysis (TGA): Methodology of calculating the degree of hydration." Construction and Building Materials 146, no. : 687-701.
The association of natural fibers and raw land soil has many advantages (thermal control, sound insulation, mechanical behavior, etc.). However, the major issue with the use of these materials is the lack of knowledge regarding their reliability and durability. In this work, we have evaluated the influence of kenaf fiber length on the mechanical and thermal properties of Compressed Earth Blocks (CEB). Fibers with length 10, 20 or 30 mm were used at mixing rate of 1.2% dry weight of soil; with the aim to enhance the mechanical and thermal properties of CEB fabricated starting from a plastic clayey soil mined in Benin. Analysis of the mechanical behavior of different Soil/Fiber formulations in terms of flexural strength demonstrated the beneficial effect of the fibers. However, the mechanical strength of CEB obtained by immersing fibers till saturation prior to incorporation into the soil greatly diminished. The higher flexural strength was obtained with fibers 30 mm long. The thermal conductivity of CEB decreased when the fiber length was raised. The results showed the real possibility to improve CEB mechanical and thermal properties by using fibers for reinforcement.
Armel B. Laibi; Philippe Poullain; Nordine Leklou; Moussa Gomina; Dominique K. C. Sohounhloué. Influence of the kenaf fiber length on the mechanical and thermal properties of Compressed Earth Blocks (CEB). KSCE Journal of Civil Engineering 2017, 22, 785 -793.
AMA StyleArmel B. Laibi, Philippe Poullain, Nordine Leklou, Moussa Gomina, Dominique K. C. Sohounhloué. Influence of the kenaf fiber length on the mechanical and thermal properties of Compressed Earth Blocks (CEB). KSCE Journal of Civil Engineering. 2017; 22 (2):785-793.
Chicago/Turabian StyleArmel B. Laibi; Philippe Poullain; Nordine Leklou; Moussa Gomina; Dominique K. C. Sohounhloué. 2017. "Influence of the kenaf fiber length on the mechanical and thermal properties of Compressed Earth Blocks (CEB)." KSCE Journal of Civil Engineering 22, no. 2: 785-793.
In the present paper, the original micro-dilatation theory or the so-called void elasticity and classical elasticity have been firstly implemented as the cement paste and aggregates, respectively. The effect of crystallization pressure driven by the delayed ettringite formation across the cement-based materials has been computed and studied via the micro-dilatation theory and the Monte Carlo simulation. The micro-mechanically motivated crystallization pressure is computed by means of the microscale constitutive parameter of the micro-dilatation theory to obtain the current porosity and assess the swelling deformations herein. Two-phase material assumption, i.e., cement paste and aggregates, has been taken into account. Due to the fact that the crystallization pressure strongly depends on the irregular pore shapes and heterogeneous supersaturation conditions, the Monte Carlo simulation has been successfully achieved to predict the current porosity and crystallization-based stress tensor. The preliminary numerical outcomes fairly agreed with the experimental observations coming from scanning electronic microscope.
Jena Jeong; Hamidréza Ramézani; Nordine Leklou. Porous-micro-dilatation theory for random crystallization: Monte Carlo simulation for delayed ettringite formation. Acta Mechanica 2017, 228, 3223 -3249.
AMA StyleJena Jeong, Hamidréza Ramézani, Nordine Leklou. Porous-micro-dilatation theory for random crystallization: Monte Carlo simulation for delayed ettringite formation. Acta Mechanica. 2017; 228 (9):3223-3249.
Chicago/Turabian StyleJena Jeong; Hamidréza Ramézani; Nordine Leklou. 2017. "Porous-micro-dilatation theory for random crystallization: Monte Carlo simulation for delayed ettringite formation." Acta Mechanica 228, no. 9: 3223-3249.
Delayed Ettringite Formation (DEF) is seen as a form of internal sulfate attack of cementitious materials, caused by early age heating to a temperature higher than 70°C. In this paper, the effect of fly ash on delayed ettringite formation of heat-cured cementbased mortars was investigated. To fulfil the aim of this study, a portion of cement was replaced by class F-fly ash, with three different dosages (10, 20 and 30%). The mortars were heat-cured at early-age, and the tests of expansion, mechanical strength, dynamic elastic modulus, mercury porosity and thermogravimetric analysis were carried on these mortars along a period of 650 days. Additionally, Scanning Electron Microscopy (SEM) observations were realized. The results obtained highlighted the mitigation effects of fly ash on DEF: A replacement of the cement used with 20% to 30% of fly ash was efficient to eliminate the long-term swelling due to DEF. This positive impact was explained by the combined effects of the high Al2O3 content of fly ash and the portlandite consumption induced by the pozzolanic reactions.
Nordine Leklou; Van-Huong Nguyen; Pierre Mounanga. The effect of the partial cement substitution with fly ash on Delayed Ettringite Formation in heat-cured mortars. KSCE Journal of Civil Engineering 2016, 21, 1359 -1366.
AMA StyleNordine Leklou, Van-Huong Nguyen, Pierre Mounanga. The effect of the partial cement substitution with fly ash on Delayed Ettringite Formation in heat-cured mortars. KSCE Journal of Civil Engineering. 2016; 21 (4):1359-1366.
Chicago/Turabian StyleNordine Leklou; Van-Huong Nguyen; Pierre Mounanga. 2016. "The effect of the partial cement substitution with fly ash on Delayed Ettringite Formation in heat-cured mortars." KSCE Journal of Civil Engineering 21, no. 4: 1359-1366.
In the present study, the chemo-thermal modeling of time-dependent hydration phenomenon of the recycled-aggregate-based mortar and natural-aggregate-based mortar has been achieved via the modified Arrhenius’ law and 3D finite element analyses. The experimental measurements about the heat release rate and total hydration heat have been taken into account for the numerical experiments later on. The numerical results confirm that hydration gradient across the cement paste matrix is disturbed by the existence of aggregates during the hydration process for both mortars. The gap spaces between cement paste and aggregates at Interfacial Transition Zone (ITZ) have been studied via Replica Method. However, the comparison among the numerical and experimental findings reveals that the numerical solutions provide different outcomes at ITZ for recycling mortar specimens. This matter substantiates that the modified Arrhenius’ law can not be applied to the recycling mortar hydration modeling and needs to be revised to take into account the additional considerations pertaining to the thermo-chemically activated reactions through the recycled aggregates including cement pastes at very early age. Some fresh routes in the analytical and numerical modeling of the recycled-sand-based mortars are discussed.
Jena Jeong; Hamidréza Ramézani; Nordine Leklou. Why does the modified Arrhenius’ law fail to describe the hydration modeling of recycled aggregate? Thermochimica Acta 2016, 626, 13 -30.
AMA StyleJena Jeong, Hamidréza Ramézani, Nordine Leklou. Why does the modified Arrhenius’ law fail to describe the hydration modeling of recycled aggregate? Thermochimica Acta. 2016; 626 ():13-30.
Chicago/Turabian StyleJena Jeong; Hamidréza Ramézani; Nordine Leklou. 2016. "Why does the modified Arrhenius’ law fail to describe the hydration modeling of recycled aggregate?" Thermochimica Acta 626, no. : 13-30.
International audienceIn the present study, the chemo-physical modeling of time dependent hydration phenomenon of the cement-based concrete materials has been achieved using the finite element method. For this study, two identical concretes have been considered with different aggregate size distribution, i.e. one contains small aggregates, 4–8 [mm] and the other contains larger aggregates, 8–12 [mm]. The experimental measurements about the heat release rate and total hydration heat have been taken into account for the numerical modeling using the modified Arrhenius's law. The numerical results confirm that the initially homogeneous hydration phenomenon across the cement paste matrix is disturbed by the existence of aggregates during the hydration period. This induced heterogeneous hydration field strongly depends on the size of aggregates. Afterwards, the hydration gradient has been scrutinized. This can readily explain not only the gap space creation which can be generally observed around the aggregates but also the particular mechanical properties and the induced hydrate product concentration at ITZ (Interfacial Transition Zone) next to the aggregates
Jena Jeong; Hamidréza Ramézani; Nordine Leklou. Thermo-chemical heterogeneous hydration gradient modeling of concrete and aggregates size effect on ITZ. Thermochimica Acta 2014, 590, 165 -180.
AMA StyleJena Jeong, Hamidréza Ramézani, Nordine Leklou. Thermo-chemical heterogeneous hydration gradient modeling of concrete and aggregates size effect on ITZ. Thermochimica Acta. 2014; 590 ():165-180.
Chicago/Turabian StyleJena Jeong; Hamidréza Ramézani; Nordine Leklou. 2014. "Thermo-chemical heterogeneous hydration gradient modeling of concrete and aggregates size effect on ITZ." Thermochimica Acta 590, no. : 165-180.
International audienceDelayed Ettringite Formation (DEF) is an internal sulfate attack caused by early age heating to a temperature of over 70 degrees C. In this paper, the effect of natural Algerian pozzolan on the expansion of cement mortars caused by DEF was investigated. For this purpose, a portion of cement was replaced by natural pozzolan, with three different dosages (10%, 20% and 30%) and finenesses (fine, medium, and coarse). The results obtained highlighted the significant effects of natural pozzolan on DEF and the correlation existing between the expansion of the heat-cured mortars and the evolution of their mechanical properties
Van-Huong Nguyen; Nordine Leklou; Jean-Emmanuel Aubert; Pierre Mounanga. The effect of natural pozzolan on delayed ettringite formation of the heat-cured mortars. Construction and Building Materials 2013, 48, 479 -484.
AMA StyleVan-Huong Nguyen, Nordine Leklou, Jean-Emmanuel Aubert, Pierre Mounanga. The effect of natural pozzolan on delayed ettringite formation of the heat-cured mortars. Construction and Building Materials. 2013; 48 ():479-484.
Chicago/Turabian StyleVan-Huong Nguyen; Nordine Leklou; Jean-Emmanuel Aubert; Pierre Mounanga. 2013. "The effect of natural pozzolan on delayed ettringite formation of the heat-cured mortars." Construction and Building Materials 48, no. : 479-484.
After mixing of the cement with water, most of the anhydride products sustain the hydration process and this leads to the hydrate products, e.g. CSH, Ca(OH)2, Afm and Aft. The mentioned hydration process is a highly complex phenomenon involving the chemically based thermo-activation inside the cement mortars during the early age hydration process. The chemo-thermal hydration reactions drasticaly increase at the early age of hydration after the mixing action and then it becomes less important and turns to be nearly asymptotic. The progress of the hydration phenomenon drives the material properties change during the very early age of cement hydration. Regarding the mortar and concrete, such hydration process would not be homogeneous through the cement matrix due to the aggregates presence. These inclusions will affect the temperature distribution as well as degree of hydration. In the current contribution, the chemical and thermal hydration have been firstly investigated by means of SEM observations using replica method and secondly by the 3D-FEM numerical experiments including two different case studies using glass beads as aggregates. The numerical experiments match fairly good the experimental measurements obtained using a pseudo-adiabatic testing setup for the case studies herein. The scanning electron microscopy (SEM) images observation demonstrates the gap spaces around the glass beads next to the external surfaces. These gaps can be essentially seen for the multi-glass beads case study. The role of the temperature and degree of hydration gradients are clearly obtained using the numerical samples. Some fresh routes and outlooks have been afterwards discussed.
Jena Jeong; Hamidréza Ramézani; Ali-Nordine Leklou; Pierre Mounanga. Chemo-physical modeling of cement mortar hydration: Role of aggregates. Thermochimica Acta 2013, 564, 70 -82.
AMA StyleJena Jeong, Hamidréza Ramézani, Ali-Nordine Leklou, Pierre Mounanga. Chemo-physical modeling of cement mortar hydration: Role of aggregates. Thermochimica Acta. 2013; 564 ():70-82.
Chicago/Turabian StyleJena Jeong; Hamidréza Ramézani; Ali-Nordine Leklou; Pierre Mounanga. 2013. "Chemo-physical modeling of cement mortar hydration: Role of aggregates." Thermochimica Acta 564, no. : 70-82.
The work presented in this paper studies the leaching of heat-cured mortars affected by delayed ettringite formation (DEF). For this, the expansion and the leaching of various elements (OH−, Ca2+, Na+ and K+) were monitored for more than 5 years in three mortars: a reference mortar and two compositions in which 3·11% of Na2SO4 (sodium sulfate) and 1·75% of NaOH (sodium hydroxide) were added to the mixture. The four mortars expanded but with different kinetics. pH, conductivity and leaching of calcium had the same global variation: a fast decrease during the first few days of curing, a strong increase after the beginning of the expansions and, lastly, a plateau of several months followed, or not (depending on the mixtures and the progress of the reaction), by a strong decrease in leaching. Finally, the results suggest that the reasons for DEF are not only related to the leaching of alkalis.
Jean-Emmanuel Aubert; Gilles Escadeillas; Nordine Leklou. Five year monitoring of curing solutions of heat-cured mortars affected by delayed ettringite formation. Advances in Cement Research 2013, 25, 155 -163.
AMA StyleJean-Emmanuel Aubert, Gilles Escadeillas, Nordine Leklou. Five year monitoring of curing solutions of heat-cured mortars affected by delayed ettringite formation. Advances in Cement Research. 2013; 25 (3):155-163.
Chicago/Turabian StyleJean-Emmanuel Aubert; Gilles Escadeillas; Nordine Leklou. 2013. "Five year monitoring of curing solutions of heat-cured mortars affected by delayed ettringite formation." Advances in Cement Research 25, no. 3: 155-163.
The work presented in this article studies the effects of some parameters that can be considered, a priori, as important in the appearance of delayed ettringite formation (DEF). The parameters studied are the nature of the binder, the water/cement (W/C) ratio, the preliminary microcracking (wetting–drying cycles) and the curing conditions. The results presented show that the chemical composition of cement is one of the main parameters controlling the appearance of DEF. The other parameters studied, (W/C ratio, wetting–drying cycles and temperature of curing water) principally modify the kinetics of the expansion: it seems that, the more favourable the conditions are to ionic and hydrous transfers, the sooner the expansion starts. Finally, the renewal of the curing water strongly affects the start of DEF. In one case of the study, the renewal of the curing water only accelerated the start of the expansion. In the second, it led to late starting of DEF (four years) whereas the same mixture cured continuously in water that was not renewed still had not expanded after more than five years. L’étude présentée dans cet article a pour objectif d’observer les effets de certains paramètres que l’on peut qualifier a priori d’importants vis-à-vis de l’apparition de la DEF. Les paramètres étudiés sont la nature du liant, le rapport E/C des mélanges, le préendommagement des éprouvettes (cycles d’humidification-séchage) et, enfin, les conditions de conservation des échantillons. Les résultats présentés montrent que la composition chimique du ciment est l’un des principaux paramètres contrôlant l’apparition de la DEF. Les autres paramètres étudiés (rapport E/C, cycles d’humidification-séchage et la température de l’eau de conservation des échantillons), modifient principalement la cinétique de l’expansion: il semble que plus les conditions sont favorables pour améliorer les transferts ioniques et hydriques, plus l’apparition des expansions est accélérée. Enfin, le renouvellement de l’eau de conservation affecte fortement le début de l’apparition de la DEF. Dans un cas d’étude, il n’a fait qu’accélérer le début de l’expansion. Dans un second cas, le renouvellement de l’eau de conservation a permis le déclenchement de la DEF au bout de 4 ans, alors que le même mélange conservé en permanence dans l’eau qui n’a pas été renouvelé n’avait pas encore montré de gonflement après plus de 5 ans.
Nordine Leklou; Jean-Emmanuel Aubert; Gilles Escadeillas. Influence of various parameters on heat-induced internal sulphate attack. European Journal of Environmental and Civil Engineering 2013, 17, 141 -153.
AMA StyleNordine Leklou, Jean-Emmanuel Aubert, Gilles Escadeillas. Influence of various parameters on heat-induced internal sulphate attack. European Journal of Environmental and Civil Engineering. 2013; 17 (3):141-153.
Chicago/Turabian StyleNordine Leklou; Jean-Emmanuel Aubert; Gilles Escadeillas. 2013. "Influence of various parameters on heat-induced internal sulphate attack." European Journal of Environmental and Civil Engineering 17, no. 3: 141-153.
This article, which deals with the effect of wetting–drying (W-D) cycles on materials affected by delayed ettringite formation (DEF), has two main objectives. The first is to observe whether W-D cycles pre-damage samples, by using the replica technique. Scanning electron microscopy (SEM) observations of replicas show that W-D cycles lead to microcracks in the samples. The second objective of the study is to observe whether the cycles are necessary for development of DEF or if they only accelerate DEF. A study of the expansion of the samples shows that cycles accelerate the appearance of expansion but they are not a prerequisite for triggering DEF. Cet article, qui porte sur l’effet des cycles d’humidification-séchage des matériaux atteints de DEF, a deux objectifs principaux. Le premier objectif est d’observer par l’utilisation de la technique de la réplique, si les cycles d’humidification-séchage pré-endommageaient les échantillons. Les résultats obtenus par le suivi des répliques ont permis de conclure que les cycles pré-endommagent les éprouvettes. Le second objectif de cette étude, est d’observer si les cycles sont nécessaires au développement de la DEF ou s’ils ne font qu’accélérer la DEF. Le suivi des expansions a montré que les cycles permettent d’accélérer l’apparition des expansions, mais qu’ils ne sont pas un préalable nécessaire pour le déclenchement de la DEF.
N. Leklou; J.-E. Aubert; G. Escadeillas. Effect of wetting-drying cycles on mortar samples affected by DEF. European Journal of Environmental and Civil Engineering 2012, 16, 582 -588.
AMA StyleN. Leklou, J.-E. Aubert, G. Escadeillas. Effect of wetting-drying cycles on mortar samples affected by DEF. European Journal of Environmental and Civil Engineering. 2012; 16 (5):582-588.
Chicago/Turabian StyleN. Leklou; J.-E. Aubert; G. Escadeillas. 2012. "Effect of wetting-drying cycles on mortar samples affected by DEF." European Journal of Environmental and Civil Engineering 16, no. 5: 582-588.
Jena Jeong; Lixi Wang; Franziska Schmidt; Nordine Leklou; Hamidréza Ramézani. Random materials modeling : Statistical approach proposal for recycling materials. 2021, 1 .
AMA StyleJena Jeong, Lixi Wang, Franziska Schmidt, Nordine Leklou, Hamidréza Ramézani. Random materials modeling : Statistical approach proposal for recycling materials. . 2021; ():1.
Chicago/Turabian StyleJena Jeong; Lixi Wang; Franziska Schmidt; Nordine Leklou; Hamidréza Ramézani. 2021. "Random materials modeling : Statistical approach proposal for recycling materials." , no. : 1.