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Full-Text Articles in Architecture
Viscoelastic Properties Of Fresh Cement Paste: Measuring Procedures And Influencing Parameters, Ammar Yahia, Arnaud Perrot, Dimitri Feys, Kamal Khayat, Mohammed Sonebi, Shiho Kawashima, Wolfram Schmidt
Viscoelastic Properties Of Fresh Cement Paste: Measuring Procedures And Influencing Parameters, Ammar Yahia, Arnaud Perrot, Dimitri Feys, Kamal Khayat, Mohammed Sonebi, Shiho Kawashima, Wolfram Schmidt
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Fresh cement pastes behave as viscoelastic materials below the flow onset. The measurements of viscoelastic properties of fresh cement paste provide valuable insight into the dispersion of solid particles as well as the hydration kinetics at early age and its influence on the structural evolution and solidification behavior at quasi-static conditions. Monitoring the development of viscoelastic properties of fresh cement paste using dynamic oscillatory shear measurements can also elucidate the working mechanisms of chemical admixtures. These properties are efficient indicators to guide mixture proportion design and are necessary to understand the rheology and stability of concrete. In this paper, the …
Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—A Comprehensive Flow Curve Analysis, Dimitri Feys, Helena Keller, Khadija El Cheikh, Egor Secrieru, Yannick Vanhove
Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—A Comprehensive Flow Curve Analysis, Dimitri Feys, Helena Keller, Khadija El Cheikh, Egor Secrieru, Yannick Vanhove
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A comprehensive testing program was carried out to compare the rheological properties of flowable concrete that can be obtained from different rheometers. The results obtained from seven rheometers using vane or similar geometries are discussed. A comprehensive flow curve analysis is undertaken for further comparison of the various rheometers. Partially, large differences could be observed between the results obtained from the different rheometers. However, the device-specific trendlines are shown to have significant correlations with the overall baseline. Two potential causes of differences between results are highlighted: imposition/registration of torque/rotational velocity and discrepancies between the measured material flow behavior in the …
Rheological Characterization Of Ultra-High Performance Concrete For 3d Printing, Arun R. Arunothayan, Behzad Nematollahi, Kamal Khayat, Akilesh Ramesh, Jay G. Sanjayan
Rheological Characterization Of Ultra-High Performance Concrete For 3d Printing, Arun R. Arunothayan, Behzad Nematollahi, Kamal Khayat, Akilesh Ramesh, Jay G. Sanjayan
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The authors recently developed a 3D-printable ultra-high performance fiber-reinforced concrete (3DP-UHPFRC) for additive construction of structural members with significantly reduced reliance on steel bars. This study investigates the rheological behavior of the developed 3DP-UHPFRC. The effects of two major factors affecting the performance of 3DP-UHPFRC, namely steel fiber volume (0, 1%, and 2%) and nano-clay (NC) content (0, 0.1%, and 0.2% by binder mass) on workability, static yield stress, dynamic yield stress, and apparent viscosity were determined. Test results showed that the inclusion of steel fibers and NC reduced the workability and led to a significant increase in the static …
Homogeneous Flow Performance Of Steel-Fiber Reinforced Self-Consolidating Concrete For Repair Application: A Biphasic Approach, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Homogeneous Flow Performance Of Steel-Fiber Reinforced Self-Consolidating Concrete For Repair Application: A Biphasic Approach, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In this study, fiber-reinforced self-consolidating concrete (FR-SCC) was considered as a diphasic suspension of fiber and coarse aggregate (F-A ≥ 5 mm) skeleton in mortar suspension with solid particles finer than 5 mm. The coupled effect of the volumetric content of fibers, coarse aggregate particle-size distribution, and rheological properties of the mortar on the passing ability and dynamic stability of various FR-SCC mixtures was investigated. Nine high-strength and 10 conventional-strength FR-SCC mixtures for repair application were proportioned with water-to-binder ratios (W/B) of 0.35 and 0.42, respectively, and macro steel fibers of 0.1%–0.5% volumetric contents. The dosages of high-range water-reducer (HRWR) …
Effect Of Class C And Class F Fly Ash On Early-Age And Mature-Age Properties Of Calcium Sulfoaluminate Cement Paste, Sukanta K. Mondal, Carrie Clinton, Hongyan Ma, Aditya Kumar, Monday Uchenna Okoronkwo
Effect Of Class C And Class F Fly Ash On Early-Age And Mature-Age Properties Of Calcium Sulfoaluminate Cement Paste, Sukanta K. Mondal, Carrie Clinton, Hongyan Ma, Aditya Kumar, Monday Uchenna Okoronkwo
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
To Promote the Sustainable Development of Eco-Efficient Calcium Sulfoaluminate (CSA) Cements through the Partial Replacement of the CSA Clinker with Supplementary Cementitious Waste Products, the Effects of Coal Fly Ashes on the Early-Age and Mature-Age Properties of a Calcium Sulfoaluminate (CSA)-Based Cement Paste Were Investigated. the Impacts of Both Class C and Class F Fly Ashes on the Rheological Properties, Hydration Kinetics, and Compressive Strength Development of CSA Cement Paste Were Studied. Rheology-Based Workability Parameters, Representing the Rate of Loss of Flowability, the Rate of Hardening, and the Placement Limit, Were Characterized for the Pastes Prepared with Fixed Water-To-Cement (W/c) …
Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat
Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigates the effect of individual and combined additions of CaO-based expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) on key characteristics of flowable cement paste mixtures proportioned with a water-to-cement ratio of 0.40. Of special interest is the effectiveness of these admixtures to mitigate shrinkage of cementitious materials for 3D printing. Static and dynamic yield stress, plastic and apparent viscosities, and thixotropy were evaluated at 20-min intervals up to 90 min. Compressive strength development and autogenous shrinkage were also determined. A factorial design approach was developed to evaluate the synergetic effects of the shrinkage …
Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In this study, a new empirical Square-Box test was employed to evaluate the homogeneous flow performance of fiber-reinforced self-consolidating concrete (FR-SCC) under confined-flow conditions that are typical of repair applications. The Square-Box set-up consisted of a closed-circuit box, providing 2.4-m flow distance and a closed-surface cross section of 100-mm width and 200-mm height, equipped with 0 and 4 rows of reinforcing bar grids with 45-mm clear spacing. The flow performance was assessed in terms of dynamic stability and passing ability. The investigated mixtures were considered as diphasic suspensions of fiber-coarse aggregate (F-A > 5 mm) in suspending mortars containing particles finer …
Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo
Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Poor workability is a common feature of calcium sulfoaluminate (CSA) cement paste. Multiple chemical admixtures, such as set retarders and dispersants, are frequently employed to improve the workability and delay the setting of CSA cement paste. A quantitative assessment of the compatibility, efficiency, and the effects of the admixtures on cement paste workability is critical for the design of an appropriate paste formulation and admixture proportioning. Very limited studies are available on the quantitative rheology-based method for evaluating the workability of calcium sulfoaluminate cement pastes. This study presents a novel and robust time-dependent rheological method for quantifying the workability of …
The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan
The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Due to its rheological properties, positive lead-acid battery paste can be difficult to spread on lead current collectors accurately and efficiently under industry machinery and setting. Sodium polymethacrylate dispersant was studied as an effective positive paste additive that could lower the yield stress of the paste without affecting paste density and battery performance. Under a four-blade vane rheometer setup, stress growth and oscillatory amplitude strain sweep experiments evaluated the rheological properties of positive paste with the addition of varying amounts of sodium polymethacrylate. Further, the electrochemical effects of sodium polymethacrylate were also evaluated in 2V batteries by testing positive active …
Pumping Of Concrete: Understanding A Common Placement Method With Lots Of Challenges, Dimitri Feys, Geert De Schutter, Shirin Fataei, Nicos S. Martys, Viktor Mechtcherine
Pumping Of Concrete: Understanding A Common Placement Method With Lots Of Challenges, Dimitri Feys, Geert De Schutter, Shirin Fataei, Nicos S. Martys, Viktor Mechtcherine
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Several million cubic meters of concrete are pumped daily, as this technique permits fast concrete placement. Fundamental research has been performed and practical guidelines have been developed to increase the knowledge of concrete behavior in pipes. However, the pumping process and concrete behavior are not fully understood. This paper gives an overview of the current knowledge of concrete pumping. At first, the known physics governing the flow of concrete in pipes are introduced. A series of experimental techniques characterizing concrete flow behavior near a smooth wall to predict pressure-flow rate relationships are discussed, followed by recent developments in the use …
Measuring Rheological Properties Of Cement Pastes: Most Common Techniques, Procedures And Challenges, Dimitri Feys, Rolands Cepuritis, Stefan Jacobsen, Karel Lesage, Egor Secrieru, Ammar Yahia
Measuring Rheological Properties Of Cement Pastes: Most Common Techniques, Procedures And Challenges, Dimitri Feys, Rolands Cepuritis, Stefan Jacobsen, Karel Lesage, Egor Secrieru, Ammar Yahia
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Science of Rheology is Increasingly Used to Describe the Properties of Fresh Cement Paste. Compared to Standard Workability Tests, Rheological Properties Allow for More Fundamental Investigation, More Precise Phenomenological Description of Flow Properties and Serve as Input for Numerical Simulations. Standard Commercially Available Rheometers Are Typically Used to Perform Those Measurements. However, the Results of the Measurement Depend on the Geometry, Testing Procedure and a Number of Potential Artefacts. This Technical Letter Describes the Most Common Techniques and Procedures Used to Assess the Rheological Properties of Cement Paste, as Well as Challenges during Measurements and Actions to Counter These …
Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys
Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Pumping of Fresh Concrete is of Utmost Importance for Concrete Practice. Required Pumping Pressures Are Typically Estimated based on Design Charts. However, with the Increased Use of Chemical Admixtures and the Development of More Flowable Concrete Mixtures, the Accuracy of Traditional Design Charts is Questioned. in Recent Years, Significant Progress Has Been Obtained in Understanding the Flow of the Material in the Pumping Pipe, Including the Behavior of the Lubrication Layer Near the Pipe Surface. in Comparison with Traditional Design Charts, This Results in More Reliable Pressure Predictions When Considering Very Fluid Concrete Types Like Self-Consolidating Concrete. Some Remaining Challenges …
Development Of A Tribometer To Characterize Lubrication Layer Properties Of Self-Consolidating Concrete, Dimitri Feys, Kamal Khayat, Aurelien Perez-Schell, Rami Khatib
Development Of A Tribometer To Characterize Lubrication Layer Properties Of Self-Consolidating Concrete, Dimitri Feys, Kamal Khayat, Aurelien Perez-Schell, Rami Khatib
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Last Decade, Significant Advances Have Been Made in Investigating, Understanding and Predicting the Flow Characteristics during Pumping of Concrete. Kaplan Developed Theoretical Equations based on the Rheological and Tribological Properties of Concrete to Predict Pumping Pressures. Several Tribometers Were Developed to Characterize the Flow Properties of Concrete Along a Smooth Wall, But None of Them Allows the Use of Highly Workable Concretes. the Main Reason is that for the Calculation of the Yield Stress and Viscous Constant of the Lubrication Layer, the Concrete is Not Allowed to Be Sheared. in This Paper, a New Design for the Concrete Tribometer …
Parameters Influencing Pressure During Pumping Of Self-Compacting Concrete, Dimitri Feys, Geert De Schutter, Ronny Verhoeven
Parameters Influencing Pressure During Pumping Of Self-Compacting Concrete, Dimitri Feys, Geert De Schutter, Ronny Verhoeven
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Main Difference between Conventional Vibrated Concrete (CVC) and Self-Compacting Concrete (SCC) is Observed in the Fresh State, as SCC Has a Significantly Lower Yield Stress. on the Other Hand, the Placement of SCC by Means of Pumping is Done with the Same Equipment and Following the Same Practical Guidelines Developed for CVC. It Can Be Questioned Whether the Flow Behavior in Pipes of SCC is Different and Whether the Developed Practical Guidelines Can Still Be Applied. This Paper Describes the Results of Full-Scale Pumping Tests Carried Out on Several SCC Mixtures. It Shows Primarily that the Slump or Yield …
Extension Of The Reiner-Riwlin Equation To Determine Modified Bingham Parameters Measured In Coaxial Cylinders Rheometers, Dimitri Feys, Jon E. Wallevik, Ammar Yahia, Kamal H. Khayat, Olafur H. Wallevik
Extension Of The Reiner-Riwlin Equation To Determine Modified Bingham Parameters Measured In Coaxial Cylinders Rheometers, Dimitri Feys, Jon E. Wallevik, Ammar Yahia, Kamal H. Khayat, Olafur H. Wallevik
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Determination of the Exact Rheological Properties, in Fundamental Units, of Cementitious Materials Has Become Gradually a Necessary Step in the Domain of Concrete Science. Several Types of Rheometers and their Corresponding Transformation Equations Are Described in the Literature. in This Paper, the Reiner-Riwlin Transformation Equation, Valid for Coaxial Cylinders Rheometers, is Developed for the Modified Bingham Model, which is an Extension of the Bingham Model with a Second Order Term in the Shear Rate. the Established Transformation is Shown to Be Compatible with the Reiner-Riwlin Equation for the Bingham and Herschel-Bulkley Models. its Validation is Further Proven by Means …
Why Is Fresh Self-Compacting Concrete Shear Thickening?, Dimitri Feys, Ronny Verhoeven, Geert De Schutter
Why Is Fresh Self-Compacting Concrete Shear Thickening?, Dimitri Feys, Ronny Verhoeven, Geert De Schutter
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Rheological Properties of Fresh Concrete Are Mostly Described by Means of the Bingham Model. for Self-Compacting Concrete, the Bingham Model is Applicable in a Lot of Cases, But Some Authors Report that the Rheological Behavior is Non-Linear. the Apparent Viscosity Increases with Increasing Shear Rate and the SCC Shows Shear Thickening Behavior. Shear Thickening Becomes Important in Operations Occurring at High Shear Rates, Like Mixing and Pumping. in These Cases, Shear Thickening Should Not Be Forgotten in Order to Avoid Breaking of the Mixer, Pump or Pipes. This Paper Will Describe Two Possible Theories for Shear Thickening Behavior of …
Fresh Self Compacting Concrete, A Shear Thickening Material, Dimitri Feys, Ronny Verhoeven, Geert De Schutter
Fresh Self Compacting Concrete, A Shear Thickening Material, Dimitri Feys, Ronny Verhoeven, Geert De Schutter
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In Literature, the Rheological Properties of Concrete Have Been Investigated Thoroughly, resulting in a Simple Description, in Steady State, by Means of the Bingham Model. Self-Compacting Concrete Shows a Lower Yield Stress, Which in Some Cases is Very Close to Zero, or Can Even Appear to Be Negative When Extrapolating the Bingham Model. in the Latter Case, the Bingham Model is Not Valid and Other Solutions Must Be Found. in This Paper, the Non-Linearity - or Shear Thickening - in the Rheological Behavior of Fresh SCC is Described with the Modified Bingham Model, after the Elimination of Possible Measurement Artefacts. …