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Supplementary cementitious materials (SCMs) have been widely used not only in civil engineering concrete components, but also in (nuclear) waste treatment engineering because of their beneficial effects on microstructure, engineering properties and durability of concrete. A comprehensive experimental campaign has been undertaken to investigate the effects of SCMs, which includes silica fume (SF) and blast furnace slag (BFS) in combination with ordinary Portland cement (OPC) on the behaviour of hydration heat evolution during early ages of mortars. The samples with different water/cement (w/c) ratios (0.5, 0.7, 0.9) and replacement ratios of SF (10%, 20%, 30%) and BFS (30%, 50%, 70%) were subjected to isothermal calorimetry tests at various temperatures (20, 30, 40 and 50 °C) in order to assess the effects of SCMs on the rate of hydration heat, cumulative heat release, activation energy and setting times of blended mortars. Knowledge obtained from these blended systems was then applied for cementation of a heavy metal containing waste sludge simulant, where the potential for thermal cracking and delayed ettringite formation due to hydration heat generation is of great concern. Results show that both BFS and SF increase the hydration rate but reduce cumulative heat release compared to pure OPC mortar. The ternary system (OPC:BFS:SF) exhibits different hydration characteristics compared to the binary system (OPC:BFS(or SF)) and there is a slight interaction between BFS and SF. The presence of sludge in the matrix significantly accelerates the hydration process and reduces the apparent activation energy. The role of temperature is more important for mortars containing BFS rather than SF, and less pronounced for the system containing sludge. Estimating the setting times based on the isothermal calorimetry data is more accurate for the final setting time rather than for initial setting time and an overestimation of 10% might occur or even more for the system containing sludge, which is still acceptable taking into account the measurement uncertainty.
Quoc Tri Phung; Eduardo Ferreira; Suresh Seetharam; Van Tuan Nguyen; Joan Govaerts; Elie Valcke. Understanding hydration heat of mortars containing supplementary cementitious materials with potential to immobilize heavy metal containing waste. Cement and Concrete Composites 2020, 115, 103859 .
AMA StyleQuoc Tri Phung, Eduardo Ferreira, Suresh Seetharam, Van Tuan Nguyen, Joan Govaerts, Elie Valcke. Understanding hydration heat of mortars containing supplementary cementitious materials with potential to immobilize heavy metal containing waste. Cement and Concrete Composites. 2020; 115 ():103859.
Chicago/Turabian StyleQuoc Tri Phung; Eduardo Ferreira; Suresh Seetharam; Van Tuan Nguyen; Joan Govaerts; Elie Valcke. 2020. "Understanding hydration heat of mortars containing supplementary cementitious materials with potential to immobilize heavy metal containing waste." Cement and Concrete Composites 115, no. : 103859.
This study examined the effectiveness of zeolite addition to reduce the autogenous shrinkage of high-performance cement-based concrete (HPC). The zeolites were replaced up to 15% of the cement content by weight and their mean particle size varied from 5.6 to 16.7 µm. To evaluate the crack resistance of HPC containing zeolites, the ring tests and internal relative humidity measurements were performed at different ages. The compressive strengths were determined at 3, 7, 28 and 90 days of curing. Test results confirmed that the addition of zeolite was promising and favourable in enhancing the compressive strength, crack resistance and reducing the autogenous shrinkage of HPC due to synergistic pozzolanic and internal curing effects. The autogenous shrinkage tended to decrease with the increase in zeolite content and its particle size. In addition, the extent of the autogenous shrinkage development at the early ages decreased with higher zeolite content replaced. Furthermore, to predict the autogenous shrinkage of HPC containing zeolite, an improved model has been proposed, in which the conventional ultimate autogenous shrinkage strain and time function were modified by introducing new parameters accounting for the zeolite content and its particle size. It appeared that the proposed model was able to capture the autogenous shrinkage behaviour of HPC with or without zeolite, while the fib 2010 model underestimated the autogenous shrinkage of HPC containing less than 10% zeolite replacement.
Nguyen Cong Thang; Nguyen Van Tuan; Keun-Hyeok Yang; Quoc Tri Phung. Effect of Zeolite on Shrinkage and Crack Resistance of High-Performance Cement-Based Concrete. Materials 2020, 13, 3773 .
AMA StyleNguyen Cong Thang, Nguyen Van Tuan, Keun-Hyeok Yang, Quoc Tri Phung. Effect of Zeolite on Shrinkage and Crack Resistance of High-Performance Cement-Based Concrete. Materials. 2020; 13 (17):3773.
Chicago/Turabian StyleNguyen Cong Thang; Nguyen Van Tuan; Keun-Hyeok Yang; Quoc Tri Phung. 2020. "Effect of Zeolite on Shrinkage and Crack Resistance of High-Performance Cement-Based Concrete." Materials 13, no. 17: 3773.
Pressure swing adsorption (PSA) appears to be an effective technology for biogas upgrading under different operating conditions with low greenhouse gas emissions. This study presents the simulation of biomethane adsorption with the adsorption bed filled with a carbon molecular sieve (CMS). A six dual-bed six-step PSA process was studied which produced a high purity of biomethane. The design of the adsorption bed was followed by the real process of which the biomethane capacity was more than 5000 Nm3/h. For the adsorbent, a CMS-3K was used, and a biomethane gas with a minimum 92% purity was produced at 6.5 bar adsorption pressure. To understand the adsorption characteristics of the CH4 and CO2 gases, the Langmuir isotherm model was used to determine the isotherm of a mixed gas containing 55% CH4 and 45% CO2. Furthermore, the experimental data from the work of Cavenati et al. were used to investigate the kinetic parameter and mass transfer coefficient. The mass transfer coefficients of two species were determined to be 0.0008 s−1 and 0.018 s−1 at 306 K for CH4 and CO2, respectively. The PSA process was then simulated with a cyclic steady state until the relative tolerance was 0.0005, which was then used to predict the CH4 and CO2 mole fraction along the adsorption bed length at a steady state. Moreover, the optimal conditions were analyzed using Aspen Adsorption to simulate various key operating parameters, such as flowrate, adsorption pressure and adsorption time. The results show a good agreement between the simulated results and the real operating data obtained from the company REBiofuel. Finally, the sensitivity analysis for the major parameters was presented. The optimal conditions were found to be an adsorption pressure of 6 bar, an adsorption time of 250 s and a purity of up to 97.92% with a flowrate reducing to 2000 Nm3/h. This study can serve as a commercial approach to reduce operating costs.
Bundit Kottititum; Thongchai Srinophakun; Niwat Phongsai; Quoc Tri Phung. Optimization of a Six-Step Pressure Swing Adsorption Process for Biogas Separation on a Commercial Scale. Applied Sciences 2020, 10, 4692 .
AMA StyleBundit Kottititum, Thongchai Srinophakun, Niwat Phongsai, Quoc Tri Phung. Optimization of a Six-Step Pressure Swing Adsorption Process for Biogas Separation on a Commercial Scale. Applied Sciences. 2020; 10 (14):4692.
Chicago/Turabian StyleBundit Kottititum; Thongchai Srinophakun; Niwat Phongsai; Quoc Tri Phung. 2020. "Optimization of a Six-Step Pressure Swing Adsorption Process for Biogas Separation on a Commercial Scale." Applied Sciences 10, no. 14: 4692.
A coupled numerical approach is used to evaluate the influence of pore connectivity and microcracks on leaching kinetics in fully saturated cement paste. The unique advantage of the numerical model is the ability to construct and evaluate a material with controlled properties, which is very difficult under experimental conditions. Our analysis is based on two virtual microstructures, which are different in terms of pore connectivity but the same in terms of porosity and the amount of solid phases. Numerical fracturing was performed on these microstructures. The non-fractured and fractured microstructures were both subjected to chemical leaching. Results show that despite very different material physical properties, for example, pore connectivity and effective diffusivity, the leaching kinetics remain the same as long as the amount of soluble phases, i.e., buffering capacity, is the same. The leaching kinetics also remains the same in the presence of microcracks.
Janez Perko; Neven Ukrainczyk; Branko Šavija; Quoc Tri Phung; Eddie A. B. Koenders. Influence of Micro-Pore Connectivity and Micro-Fractures on Calcium Leaching of Cement Pastes—A Coupled Simulation Approach. Materials 2020, 13, 1 .
AMA StyleJanez Perko, Neven Ukrainczyk, Branko Šavija, Quoc Tri Phung, Eddie A. B. Koenders. Influence of Micro-Pore Connectivity and Micro-Fractures on Calcium Leaching of Cement Pastes—A Coupled Simulation Approach. Materials. 2020; 13 (12):1.
Chicago/Turabian StyleJanez Perko; Neven Ukrainczyk; Branko Šavija; Quoc Tri Phung; Eddie A. B. Koenders. 2020. "Influence of Micro-Pore Connectivity and Micro-Fractures on Calcium Leaching of Cement Pastes—A Coupled Simulation Approach." Materials 13, no. 12: 1.
Many environments to which concrete is exposed are highly aggressive due to various chemical components. In such environments, concrete is subjected to processes of chemical degradation, among which carbonation is one of the most frequently seen degradation processes. Though, the influence of saturation degree (or relative humidity - RH) of the specimen and CO2 concentration on the carbonation of cementitious materials is still not comprehensively described with respect to carbonation rate/degree as well as alteration in microstructure and mineralogy. This work aims at thoroughly investigating how these two key parameters affect the carbonation under accelerated conditions. Furthermore, the effect of initial moisture state of the specimen on the carbonation rate is also demonstrated. For such purpose, a numerical model at continuum scale is developed to investigate the effects of RH and CO2 concentration on the carbonation depth, phase changes in phases and porosity of hardened cement pastes due to carbonation under accelerated conditions. Verification with experimental results from accelerated carbonation tests shows a good agreement. The modelling results with supporting experimental data help to better understand the modification of material properties under different carbonation conditions and to optimize the carbonation conditions.
Quoc Tri Phung; Anna Varzina; Janez Perko; DiedeDiederik Jacques; Nobert Maes; Özlem Cizer. On the Effects of Relative Humidity and CO2 Concentration on Carbonation of Cement Pastes. XV International Conference on Durability of Building Materials and Components. eBook of Proceedings 2020, 1 .
AMA StyleQuoc Tri Phung, Anna Varzina, Janez Perko, DiedeDiederik Jacques, Nobert Maes, Özlem Cizer. On the Effects of Relative Humidity and CO2 Concentration on Carbonation of Cement Pastes. XV International Conference on Durability of Building Materials and Components. eBook of Proceedings. 2020; ():1.
Chicago/Turabian StyleQuoc Tri Phung; Anna Varzina; Janez Perko; DiedeDiederik Jacques; Nobert Maes; Özlem Cizer. 2020. "On the Effects of Relative Humidity and CO2 Concentration on Carbonation of Cement Pastes." XV International Conference on Durability of Building Materials and Components. eBook of Proceedings , no. : 1.
Quoc Tri Phung; Norbert Maes; Suresh Seetharam. Pitfalls in the use and interpretation of TGA and MIP techniques for Ca-leached cementitious materials. Materials & Design 2019, 182, 1 .
AMA StyleQuoc Tri Phung, Norbert Maes, Suresh Seetharam. Pitfalls in the use and interpretation of TGA and MIP techniques for Ca-leached cementitious materials. Materials & Design. 2019; 182 ():1.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Suresh Seetharam. 2019. "Pitfalls in the use and interpretation of TGA and MIP techniques for Ca-leached cementitious materials." Materials & Design 182, no. : 1.
A mesoscale damage framework is developed for investigating the extent of crack or damage penetration in a large-scale concrete component induced by corrosion process under various boundary conditions. The framework synthesizes a robust particle generation algorithm, a state of the art mesoscale damage model and a global optimization algorithm. Three-point bending experiments on geometrically similar specimens, designed to capture the size effect reasonably well, are reported and used as the basis for estimating mesoscale damage parameters. The results show how boundary conditions control damage evolution, realizing scenarios from complete penetration to arrest of damage at different penetration levels within the component. In particular, it is shown that damage is arrested under external pressure and fixed displacement boundary conditions, but fully penetrates under stress-free boundary condition. The outcome is significant for the integrity assessment of concrete elements encapsulating corroding metallic containers.
S.C. Seetharam; E. Laloy; A. Jivkov; L. Yu; Q.T. Phung; N.P. Pham; B. Kursten; F. Druyts. A mesoscale framework for analysis of corrosion induced damage of concrete. Construction and Building Materials 2019, 216, 347 -361.
AMA StyleS.C. Seetharam, E. Laloy, A. Jivkov, L. Yu, Q.T. Phung, N.P. Pham, B. Kursten, F. Druyts. A mesoscale framework for analysis of corrosion induced damage of concrete. Construction and Building Materials. 2019; 216 ():347-361.
Chicago/Turabian StyleS.C. Seetharam; E. Laloy; A. Jivkov; L. Yu; Q.T. Phung; N.P. Pham; B. Kursten; F. Druyts. 2019. "A mesoscale framework for analysis of corrosion induced damage of concrete." Construction and Building Materials 216, no. : 347-361.
The objective of this study is to quantify the contributions of microstructure and molecular size of diffusing species to tortuosity, constrictivity and effective diffusivity. The microstructural effect is simulated with different sound, leached or carbonated cement pastes with varying water to cement ratios and limestone replacement filler replacements. Leached and carbonated samples were obtained by accelerated experiments: leaching by immersing samples in ammonium nitrate solution and carbonation by subjecting the samples to pure CO2 at elevated pressure. To characterise the microstructural properties, Mercury Intrusion Porosimetry (MIP), and N2-adsorption were used. The effect of molecular size is quantified with a recent developed diffusion setup allowing for simultaneous measurement of the diffusion of species with different molecular sizes. Previously developed models were also used to verify and give insights into the evolution of diffusion of degraded materials. In addition, a larger dataset from literature is used to evaluate a model which accounts for molecular size as well to predict diffusivity. show that because of the significant contribution of the molecular size of the diffusing species to the diffusion process, the constrictivity and thereby geometric factor may not be considered as intrinsic properties of the cement pastes. The geometric factor and/or constrictivity of cement pastes depends on the interrelationship of the molecular size of the diffusing species with the microstructure of the cementitious materials. A smaller diffusing species or/and a higher porosity of the sample results in a lower value of geometric factor. Interestingly, constrictivity is significantly influenced by the molecular size, but not the porosity.
Quoc Tri Phung; Norbert Maes; Elke Jacops; Diederik Jacques; Geert De Schutter; Guang Ye. Insights and issues on the correlation between diffusion and microstructure of saturated cement pastes. Cement and Concrete Composites 2018, 96, 106 -117.
AMA StyleQuoc Tri Phung, Norbert Maes, Elke Jacops, Diederik Jacques, Geert De Schutter, Guang Ye. Insights and issues on the correlation between diffusion and microstructure of saturated cement pastes. Cement and Concrete Composites. 2018; 96 ():106-117.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Elke Jacops; Diederik Jacques; Geert De Schutter; Guang Ye. 2018. "Insights and issues on the correlation between diffusion and microstructure of saturated cement pastes." Cement and Concrete Composites 96, no. : 106-117.
This paper presents the outcome of a comprehensive experimental program undertaken to study the performance of cellulose pulp and synthetic PVA (polyvinyl alcohol) based fiber-cement composite under both carbonated and non-carbonated curing conditions at early age. The composites were produced at different rolling pressures (2.5 to 9.0 bar) and subjected to various curing conditions in which the effects of CO2 pressure (1 to 3 bar) and curing time (3 to 9 h) were studied. The mechanical properties (modulus of elasticity (MOE), modulus of rupture (MOR), and toughness), as well as the physical properties (porosity, bulk density, and water absorption), were measured for all samples. Scanning electron microscopy (SEM) was used to investigate the effect of carbonation on porosity change and adhesion of fiber-matrix. A parametric investigation of the effects of the carbonation curing period, CO2 pressure, and rolling pressure on the improvement of the physical and mechanical properties during carbonation curing was performed. Results showed that fiber-cement composites cured with an elevated CO2 pressure of 3 bar, rolling pressure of 3 bar, and 5 h of curing time provided optimal curing conditions resulting in the most desirable mechanical and physical properties. However, toughness was greatly reduced with the increase of the CO2 pressure, curing time, and rolling pressure. Additionally, the carbonation curing improved the bonding between the fiber and the cement matrix because of the precipitation of calcite particularly in the pores of the interfacial transition zone (ITZ) between the cement matrix and the fibers.
Bundit Kottititum; Quoc Tri Phung; Norbert Maes; Wichit Prakaypan; Thongchai Srinophakun. Early Age Carbonation of Fiber-Cement Composites under Real Processing Conditions: A Parametric Investigation. Applied Sciences 2018, 8, 190 .
AMA StyleBundit Kottititum, Quoc Tri Phung, Norbert Maes, Wichit Prakaypan, Thongchai Srinophakun. Early Age Carbonation of Fiber-Cement Composites under Real Processing Conditions: A Parametric Investigation. Applied Sciences. 2018; 8 (2):190.
Chicago/Turabian StyleBundit Kottititum; Quoc Tri Phung; Norbert Maes; Wichit Prakaypan; Thongchai Srinophakun. 2018. "Early Age Carbonation of Fiber-Cement Composites under Real Processing Conditions: A Parametric Investigation." Applied Sciences 8, no. 2: 190.
Nuclear power, to most of us, is mystic and somehow scary, and despite its drawbacks, is still playing an important role in the world wide energy supply. However concrete, without mystery as the most widely used materials in construction, is used as a major constituent for nuclear facilities such as radioactive waste repositories and nuclear power plants. Concrete is the only practical material offering a number of advantages including sufficient shielding against the dangers of radiation, good compressive strength, low cost, easy building, and retention of radionuclides limiting their dissipation. The assessment of the long-term durability of such concrete structures is of utmost importance and urgently needed as our knowledge on concrete durability beyond the basis of an expected several decade service life is limited. Within its service environment, these structures undergo chemical degradation processes which are very slow but they significantly change the physical integrity and the chemical conditions of the structures with the passage of time. Current issues on durability of these concrete structures include alkali-silica reaction, delayed ettringite formation, leaching, carbonation, etc. which might be magnified under severe/accelerated conditions (high temperature, radiation, moisture, cyclic loading, and acidic environments). These degradations induce an evolution of the microstructure, cracking and changes in transport properties of concrete which are still unclear due to the limited experimental timeframe available to capture these processes. This paper presents an overview on these concerns with the focus on the long-term chemical degradation aspect and presenting a case study on Ca-leaching.
Quoc Tri Phung; Norbert Maes; Diederik Jacques. Current Concerns on Durability of Concrete Used in Nuclear Power Plants and Radioactive Waste Repositories. Proceedings of EECE 2020 2017, 1107 -1121.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques. Current Concerns on Durability of Concrete Used in Nuclear Power Plants and Radioactive Waste Repositories. Proceedings of EECE 2020. 2017; ():1107-1121.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques. 2017. "Current Concerns on Durability of Concrete Used in Nuclear Power Plants and Radioactive Waste Repositories." Proceedings of EECE 2020 , no. : 1107-1121.
This paper provides a comprehensive overview of existing experimental and modelling approaches to determine effective diffusion coefficients of water saturated ordinary Portland cement-based materials. A dataset for diffusivity obtained from different experimental techniques have been presented for cement paste, mortar and concrete. For cement paste at low porosities, diffusivity reported by different authors varies up to a factor of five and electrical resistivity measurements for low capillary porosity are up to one order of magnitude higher compared to other techniques. Experimental data of mortar and concrete reveals predominant influence of increasing tortuosity due to aggregates and limited influence of interface transition zone. Hence, a particular emphasis has been placed on assessing predictability of diffusivity models for cement paste on a larger dataset collected in this paper. It has been observed that all predictive models have similar level of accuracy and fail to predict electrical resistivity data at low capillary porosity as these models are not calibrated using electrical resistivity data
Ravi A. Patel; Quoc Tri Phung; Suresh Seetharam; Janez Perko; Diederik Jacques; Norbert Maes; Geert De Schutter; Guang Ye; Klaas Van Breugel. Diffusivity of saturated ordinary Portland cement-based materials: A critical review of experimental and analytical modelling approaches. Cement and Concrete Research 2016, 90, 52 -72.
AMA StyleRavi A. Patel, Quoc Tri Phung, Suresh Seetharam, Janez Perko, Diederik Jacques, Norbert Maes, Geert De Schutter, Guang Ye, Klaas Van Breugel. Diffusivity of saturated ordinary Portland cement-based materials: A critical review of experimental and analytical modelling approaches. Cement and Concrete Research. 2016; 90 ():52-72.
Chicago/Turabian StyleRavi A. Patel; Quoc Tri Phung; Suresh Seetharam; Janez Perko; Diederik Jacques; Norbert Maes; Geert De Schutter; Guang Ye; Klaas Van Breugel. 2016. "Diffusivity of saturated ordinary Portland cement-based materials: A critical review of experimental and analytical modelling approaches." Cement and Concrete Research 90, no. : 52-72.
Because of its environmental and economic benefits, part of cement is replaced by limestone fillers (LS). However, the effect of LS on the chemical degradation of cement-based materials is still unclear. In this study, accelerated leaching and carbonation were applied on cement pastes to study the effects of LS replacement on the degradation rates and microstructural alterations of degraded materials. Ammonium nitrate solution was used to accelerate the leaching process, while carbonation was speeded up by applying an elevated pressure gradient of pure CO2 on samples with 65% relative humidity. The carbonation rate was characterized by phenolphthalein carbonation depth and CO2 uptake, while leaching rate was quantified by phenolphthalein leaching depth and Ca-leached amount. Leached/carbonated samples were analyzed by a series of post-analysis techniques to characterize the microstructural and mineralogical changes. Results showed that, for a similar w/c ratio, a higher LS replacement resulted in lower leaching rate. For carbonation, LS replacement promoted the CO2 uptake despite similar carbonation depth. Furthermore, LS replacement led to less C-S-H carbonation compared to samples without LS.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Guang Ye; Geert De Schutter. Effect of Limestone Fillers on Ca-Leaching and Carbonation of Cement Pastes. Key Engineering Materials 2016, 711, 269 -276.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Guang Ye, Geert De Schutter. Effect of Limestone Fillers on Ca-Leaching and Carbonation of Cement Pastes. Key Engineering Materials. 2016; 711 ():269-276.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Guang Ye; Geert De Schutter. 2016. "Effect of Limestone Fillers on Ca-Leaching and Carbonation of Cement Pastes." Key Engineering Materials 711, no. : 269-276.
Calcium leaching might be a significant degradation process in concrete and reinforced structures with an anticipated long-term service life such as nuclear waste disposal systems or large hydro structures (dams, bridges, water tanks). The leaching process is extremely slow under environmental conditions, which fosters the use of accelerated experimental approaches such as leaching in an ammonium nitrate (NH4NO3) solution. In this paper, we develop a one-dimensional diffusion-based transport model with the purpose to predict the changes in microstructure and transport properties of saturated cement pastes in contact with a NH4NO3 solution. The model helps to better understand the transient state of leaching which is difficult to observe by experimental work. The main new elements in this model are change in model configuration with extended solution domains; ability to predict the spatial profiles of diffusivity and permeability; including the effect on solubility of the spatial-temporal evolution of nitrate concentration; and including the effect of limestone addition to the cement paste of leaching kinetics. This model is based on macroscopic mass balances for Ca in aqueous and solid phases which are linked together by applying a variable solid-liquid Ca equilibrium curve. Besides the prediction of the leached depth, porosity increase, portlandite and C-S-H contents, and the amount of leached Ca, the model also enables to estimate the variation of permeability and diffusivity over the domain at different immersion periods in NH4NO3 solution. The model is verified by accelerated leaching experiments in 6 mol/l NH4NO3 solution on CEM I cement pastes with/without limestone fillers. Verification with experimental results shows a good agreement
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Janez Perko; Geert De Schutter; Guang Ye. Modelling the evolution of microstructure and transport properties of cement pastes under conditions of accelerated leaching. Construction and Building Materials 2016, 115, 179 -192.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Janez Perko, Geert De Schutter, Guang Ye. Modelling the evolution of microstructure and transport properties of cement pastes under conditions of accelerated leaching. Construction and Building Materials. 2016; 115 ():179-192.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Janez Perko; Geert De Schutter; Guang Ye. 2016. "Modelling the evolution of microstructure and transport properties of cement pastes under conditions of accelerated leaching." Construction and Building Materials 115, no. : 179-192.
Underground concrete structures in radioactive waste disposal have the potential to be subjected to a high hydrostatic pressure and the surrounding environment may contain a high dissolved CO2 concentration. Therefore, a combination of diffusion and advection should be taken into account when one considers the carbonation mechanism. This study aims at developing a model to predict the evolution of the microstructure and transport properties of hardened cement pastes due to carbonation under accelerated conditions in which a pressure gradient of pure CO2 is applied. The current model is improved from the preliminary model in terms of extension to limestone cement paste and accounting for the transport of moisture. The proposed model is based on a macroscopic mass balance for CO2 and moisture in both gaseous and aqueous phases. A simplified solid-liquid equilibrium curve is used to relate the Ca content in aqueous and solid phases. Besides the prediction of the changes in porosity, diffusivity, permeability, and saturation degree, the model also enables prediction of the carbonation degree, portlandite content, and CO2 uptake. Verification with experimental results from accelerated carbonation tests shows a good agreement.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye; Janez Perko. Modelling the carbonation of cement pastes under a CO2 pressure gradient considering both diffusive and convective transport. Construction and Building Materials 2016, 114, 333 -351.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Geert De Schutter, Guang Ye, Janez Perko. Modelling the carbonation of cement pastes under a CO2 pressure gradient considering both diffusive and convective transport. Construction and Building Materials. 2016; 114 ():333-351.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye; Janez Perko. 2016. "Modelling the carbonation of cement pastes under a CO2 pressure gradient considering both diffusive and convective transport." Construction and Building Materials 114, no. : 333-351.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye. Investigation of the changes in microstructure and transport properties of leached cement pastes accounting for mix composition. Cement and Concrete Research 2016, 79, 217 -234.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Geert De Schutter, Guang Ye. Investigation of the changes in microstructure and transport properties of leached cement pastes accounting for mix composition. Cement and Concrete Research. 2016; 79 ():217-234.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye. 2016. "Investigation of the changes in microstructure and transport properties of leached cement pastes accounting for mix composition." Cement and Concrete Research 79, no. : 217-234.
Q. T. Phung; N. Maes; Diederik Jacques; G. De Schutter; G. Ye. Evolution of Microstructure and Transport Properties of Cement Pastes Due to Carbonation under a CO 2 Pressure Gradient—A Modeling Approach. CONCREEP 10 2015, 1 .
AMA StyleQ. T. Phung, N. Maes, Diederik Jacques, G. De Schutter, G. Ye. Evolution of Microstructure and Transport Properties of Cement Pastes Due to Carbonation under a CO 2 Pressure Gradient—A Modeling Approach. CONCREEP 10. 2015; ():1.
Chicago/Turabian StyleQ. T. Phung; N. Maes; Diederik Jacques; G. De Schutter; G. Ye. 2015. "Evolution of Microstructure and Transport Properties of Cement Pastes Due to Carbonation under a CO 2 Pressure Gradient—A Modeling Approach." CONCREEP 10 , no. : 1.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Elke Jacops; Arno Grade; Geert De Schutter; Guang Ye; E Lantsoght; C Van Der Veen; A De Boer. Determination of diffusivities of dissolved gases in saturated cement-based materials. Concrete Repair, Rehabilitation and Retrofitting IV 2015, 221 -222.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Elke Jacops, Arno Grade, Geert De Schutter, Guang Ye, E Lantsoght, C Van Der Veen, A De Boer. Determination of diffusivities of dissolved gases in saturated cement-based materials. Concrete Repair, Rehabilitation and Retrofitting IV. 2015; ():221-222.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Elke Jacops; Arno Grade; Geert De Schutter; Guang Ye; E Lantsoght; C Van Der Veen; A De Boer. 2015. "Determination of diffusivities of dissolved gases in saturated cement-based materials." Concrete Repair, Rehabilitation and Retrofitting IV , no. : 221-222.
S. Anders; Quoc Tri Phung; Norbert Maes; Diederik Jacques; Elke Jacops; Arno Grade; Geert De Schutter; Guang Ye. Comparison of residual strengths of concretes with quarzitic, limestone and slag sand constituents after cyclic high-temperature exposure. Concrete Repair, Rehabilitation and Retrofitting IV 2015, 223 -224.
AMA StyleS. Anders, Quoc Tri Phung, Norbert Maes, Diederik Jacques, Elke Jacops, Arno Grade, Geert De Schutter, Guang Ye. Comparison of residual strengths of concretes with quarzitic, limestone and slag sand constituents after cyclic high-temperature exposure. Concrete Repair, Rehabilitation and Retrofitting IV. 2015; ():223-224.
Chicago/Turabian StyleS. Anders; Quoc Tri Phung; Norbert Maes; Diederik Jacques; Elke Jacops; Arno Grade; Geert De Schutter; Guang Ye. 2015. "Comparison of residual strengths of concretes with quarzitic, limestone and slag sand constituents after cyclic high-temperature exposure." Concrete Repair, Rehabilitation and Retrofitting IV , no. : 223-224.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Els Bruneel; Isabel Van Driessche; Guang Ye; Geert De Schutter. Effect of limestone fillers on microstructure and permeability due to carbonation of cement pastes under controlled CO 2 pressure conditions. Construction and Building Materials 2015, 82, 376 -390.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Els Bruneel, Isabel Van Driessche, Guang Ye, Geert De Schutter. Effect of limestone fillers on microstructure and permeability due to carbonation of cement pastes under controlled CO 2 pressure conditions. Construction and Building Materials. 2015; 82 ():376-390.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Els Bruneel; Isabel Van Driessche; Guang Ye; Geert De Schutter. 2015. "Effect of limestone fillers on microstructure and permeability due to carbonation of cement pastes under controlled CO 2 pressure conditions." Construction and Building Materials 82, no. : 376-390.
Quoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye. Microstructural and permeability changes due to accelerated Ca leaching in ammonium nitrate solution. Concrete Solutions 2014 2014, 431 -438.
AMA StyleQuoc Tri Phung, Norbert Maes, Diederik Jacques, Geert De Schutter, Guang Ye. Microstructural and permeability changes due to accelerated Ca leaching in ammonium nitrate solution. Concrete Solutions 2014. 2014; ():431-438.
Chicago/Turabian StyleQuoc Tri Phung; Norbert Maes; Diederik Jacques; Geert De Schutter; Guang Ye. 2014. "Microstructural and permeability changes due to accelerated Ca leaching in ammonium nitrate solution." Concrete Solutions 2014 , no. : 431-438.