Creep Compliance Research Articles

Hourly three-minute creep testing of an LC3 paste at early ages: Advanced test evaluation and the effects of the pozzolanic reaction on shrinkage, elastic stiffness, and creep

In this study, hourly three-minute creep testing is used to elucidate the evolution of the viscoelastic behavior of cement pastes produced with ordinary Portland cement (OPC), limestone Portland cement (LPC), and limestone calcined clay cement (LC3), from 1 to 7 days after production. An innovative test evaluation protocol, accounting for shrinkage, is used to identify values of the elastic modulus, the creep modulus, and the creep exponent, without making assumptions. The S-shaped shrinkage evolution of the LC3 paste is explained by Portlandite dissolution and the associated redistribution of chemical shrinkage-induced compressive stresses to the remaining solid skeleton. The evolution of the elastic stiffness of the LC3 paste is explained by space filling by C-A-S-H phases. The small creep compliance of the LC3 paste is explained by C-A-S-H which creeps less than C-S-H, and by AFm phases which precipitate in nanoscopic slit pores between C-S-H structures, gluing viscous interfaces.

Enhancements of Creep Compliance of Kevlar and Carbon Fibers Reinforced Sika Epoxy Composites

Enhancements of Creep Compliance of Kevlar and Carbon Fibers Reinforced Sika Epoxy Composites

Rutting and fatigue behavior of neat and nanomodified asphalt mixture with SiO2 and TiO2

Modern asphalt technology has adopted nanomaterials as an alternative option to assert that asphalt pavement can survive harsh climates and repeated heavy axle loading during service life and prolong pavement life. This work aims to elucidate the behavior of the modified asphalt mixture fracture model and assess the fatigue and Rutting performance of Hot Mix Asphalt (HMA) mixes using the outcomes of indirect Tensile Strength (IDT), Semicircular bend (SCB) and rutting resistance; for this, a single PG (64−16) nanomodified asphalt binder with 5 % SiO2 and TiO2 have been investigated through a series of laboratory tests, including: Resilient modulus, Creep compliance, and tensile strength, SCB, and Flow Number (FN) to study their potential role of these nanomaterials to improve the rutting characteristics and fatigue life of wearing asphalt mixture at different temperatures. The outcome of this study revealed the positive role of these materials in enhancing mixture IDT characteristics, fracture energy, and viscoelastic deformation component of crack propagation; on the other hand, at higher temperatures, the modified mixture exhibited a superior performance in reducing the permanent deformation of asphalt mixture with SiO2 followed by TiO2 as compared to neat asphalt mixture.

Evaluation and comparison for higher temperature performance index of emulsified asphalt mastic using coal gangue powder

In order to investigate the rheological behavior and the influence of solid waste coal gangue powder on the high-temperature performance of cold recycled Emulsified Asphalt Mastics (EAM), Dynamic Shear Rheometer (DSR) and Multiple Stress Creep Recovery (MSCR) tests were conducted using three different fillers and four powder-to-binder ratios of EAM. Evaluation indexes such as rutting factor (G*/sinδ), improved rutting factor (G*/1−1/sinδ∙tanδ), Unrecoverable Creep Compliance (Jnr), Cumulative Strain (CS) and Creep Recovery Ratio (R) were used to analyze the influence of filler type and dosage on high temperature of EAM, and the effectiveness of these indexes to evaluate high temperature is considered. Moreover, atomic force microscopy experiments were carried out to study on interaction mechanism between the fillers and emulsified asphalt. Finally, grey relational analysis method was used for quantitative assessment of these indexes for EAM. The results indicate that all three fillers effectively improve the high-temperature performance, with a larger improvement observed as the filler dosage increases, among which the tunneling coal gangue powder is the most significant. Under a stress level of 0.1 KPa, the coal gangue filler mastic appears the best deformation recovery ability, whereas under a stress level of 3.2 KPa, the cement filler mastics appears the best deformation recovery ability. The additional fillers significantly influence the nano-scale surface morphology of the residues, and the tunneling coal gangue powder appears a stronger adsorption capacity for free polar components compared to the cement and limestone mineral powder. It is suggested that the Jnr and CS can be used as evaluation indexes of high temperature evaluation index of EAM, instead of G*/1−1/sinδ∙tanδ or G*/sinδ or R.

Rheological and mechanical evaluation of a novel fast curing cold asphalt concrete made with asphalt emulsion, by-products and magnetic induction

This work studies the feasibility of a new cold asphalt concrete with 5 % voids with fast curing, developed with asphalt emulsion and magnetic induction. Until now, it was impossible to produce fast curing cold asphalt concretes due to the impossibility of compacting and evaporating the water in the asphalt emulsion quickly. Therefore, the aim of this work is to solve the impossibility of compacting the cold asphalt concrete and thus reduce the long curing times. For this purpose, at laboratory level, an experimental cold asphalt concrete was designed with magnetic induction and compared with two reference hot asphalt concretes manufactured according to Spanish standards without magnetic induction (one with 50–70 grade bitumen and another with a PMB45/80–65 type polymer-modified bitumen). The research was carried out in two stages. First, the new cold asphalt concrete was rheologically characterized, the binder recovered from the asphalt concrete was analyzed according to the tests of ring and ball, penetration, dynamic shear rheometer (DSR) and multiple stress creep and recovery (MSCR). Secondly, the new cold concrete asphalt was mechanically characterized, the mechanical performance of the cold asphalt concrete was analyzed by evaluating stability and deformation, dry and wet indirect tensile strengths (ITS), wheel tracking test, stiffness modulus and resistance to raveling dry and wet conditions. Based on the rheological analysis results, the asphalt emulsion recovered from the cold asphalt concrete is extremely soft with a low softening point and a high penetration rate. On the other hand, the values of viscosity, phase angle, stiffness and non-recoverable creep compliance are between those of the bitumen 50/70 and the PMB45/80–65, but closer to bitumen 50/70. As for their mechanical performance, the novel cold asphalt concrete studied presents better resistance to water damage and particle loss, both in dry and wet conditions, but also high permanent deformations and low ITS, probably due to the fact that the residual binder of the emulsion used is softer than the others.

Development of SBS composite modified asphalt incorporating polydopamine-enhanced MoS2

This study investigated the development of a novel composite modified asphalt incorporating PDA-MoS2 into styrene-butadiene-styrene (SBS) modified asphalt. The successful synthesis of PDA-MoS2 was confirmed through various characterization techniques. The incorporation of PDA-MoS2 into SBS modified asphalt resulted in significant improvements in performance properties. With a PDA-MoS2 content of 0.7 wt%, the modified asphalt showed a notable 15.1% rise in softening point and a 24% drop in penetration in comparison to the control SBS modified asphalt. Dynamic Shear Rheometer tests revealed a 2.4-fold increase in the rutting factor at 60°C. Multiple Stress Creep Recovery tests demonstrated enhanced rutting resistance, with a 72.2% reduction in nonrecoverable creep compliance at 0.1 kPa stress level. Electrochemical measurements showed improved corrosion resistance, evidenced by lower current densities and higher charge transfer resistance. Microstructural analysis revealed well-dispersed PDA-MoS2 particles forming a compact network structure within the asphalt matrix. The hydrophilicity of the modified asphalt increased, with a 35.3% decrease in water contact angle. The synergistic effect between PDA-MoS2, SBS, and asphalt components, facilitated by enhanced interfacial interactions and chemical bonding, contributed to the observed performance improvements. The results indicate that PDA-MoS2 has the potential to improve the characteristics of SBS modified asphalt as a modifier.

A Description of the Isothermal Ageing Creep Process in Polymethyl Methacrylate Using Fractional Differential Models.

Fractional differential viscoelastic models can describe complex material behaviours and fit experimental data well; however, the physical significance of model parameters is difficult to express. In this study, the fractional differential Maxwell, Kelvin, and Zener models were used to fit the short-term creep compliance curves of polymethyl methacrylate at different ageing times. The model fits were in good agreement with the experimental data. As the ageing time increased, the fractional differential Zener model showed a relative increase in the modulus parameter of the spring and a relative decrease in the modulus parameter reflecting the viscosity of the spring-pot, which indicated that physical ageing made the material more elastic. The relaxation time of the material increased, which indicated that the physical ageing reduced the free volume of the material, hindered the movement of molecules/segments, and increased the time required for the material to reach equilibrium. The fractional order of the model decreased, which reflected the phenomenon that physical ageing reduced the creep compliance of the material. Using the relaxation time as the time scale, the creep curves at different ageing times under the same stress level could be superimposed, naturally presenting the time-ageing time equivalence principle.

Modelling the time-dependent mechanical properties of thermoplastic and thermosetting polymers with Gumbel distribution functions

In this paper, we propose a simple modelling method that accurately describes the time-dependent viscoelastic behaviour of thermoplastic and thermosetting solid polymers. We performed short-term creep and stress relaxation tests on representative samples of three major classes of polymers: an amorphous, a semi-crystalline thermoplastic and a thermosetting polymer. Then, to investigate the relationship between the model parameters and the material composition, we also tested thermoplastic matrix composites with different plasticiser contents. From the short-term tests, master curves were constructed with the use of the time–temperature superposition principle. Then, the temperature dependence of the obtained shift factors was described using the Arrhenius model. The resulting creep compliance and relaxation modulus master curves were normalised and modelled with a two-parameter cumulative Gumbel distribution function (CDF) and its complementary distribution function (CCDF). For the creep and stress relaxation master curves, the median error of modelling was less than 16 % and 16.5 % in all cases, respectively. Furthermore, it was less than 2 % for the thermosetting polymer, making this model an excellent tool for describing the creep and stress relaxation behaviour of thermosetting systems. In the case of the plasticised composites, we found a strong relationship between the material composition and the location parameter of the Gumbel model. Based on this, we developed a method that can be used to estimate the evolution of the creep compliance curve for any arbitrary OLA content (between 0 wt% and 16 wt%) at any desired temperature (between 22 °C and 70 °C).

Performance Characterization of the Field Aged Asphalt Pavement Materials at Mortar Scale: Testing Method Optimization and Rheology Analysis

Performance evaluation at the asphalt mortar scale offers increased sensitivity to aging and is less affected by extraction processes comparated to asphalt mixture. Despite these benefits, there is currently a lack of standardized methods for directly processing mortar samples obtained from field mixtures. This study aims to improve and validate a manufacturing procedure for aged mortar specimens derived from field aging cores, and to evaluate the field damage level of asphalt paving materials at the mortar scale. A novel approach was developed that incorporates warm sieving, compaction, coring, and cutting to manufacture mortar specimens suitable for Dynamic Shear Rheometer (DSR) tests. This study selected mortar specimens with different service ages and conducted rheological tests, including frequency sweep tests and modified Multiple Stress Creep Recovery (MSCR) tests, to assess their rheological performance. And the significance test of all the indcies were conducted to select suitable indcies.The results show the proposed aged mortar manufacture approach can prepare eligible mortar specimens for rheology tests. The rheology test results show that several indices can distinguish different mortar types and service ages, and the indices of surface layer mortar follow a linear relationship with service age. The linear viscoelastic zone (LVE), representative shear modulus (G0), and unrecovered creep compliance at 1.6kPa (Jnr1.6) and 3.2kPa (Jnr3.2) are identified as effective indices for evaluating the behavior of field aged mortar because of their effectiveness, lower variability, and better distinction.

Stress and power as a response to harmonic excitation of a fractional anti‐Zener and Zener type viscoelastic body

AbstractThe stress as a response to strain prescribed as a harmonic excitation is examined in both transient and steady state regime for the viscoelastic body modeled by thermodynamically consistent fractional anti‐Zener and Zener models by the use of the Laplace transform method. Assuming strain as a sine function, the time evolution of power per unit volume, previously derived as a sum of time derivative of a conserved term, which represents the rate of change of stored energy, and a dissipative term, which represents dissipated power, is investigated when expressed through the relaxation modulus and creep compliance. Further, two forms of energy and two forms of dissipated power per unit volume are examined in order to see whether they coincide.

An efficient and robust method for evaluating the low-temperature performance of asphalt binder based on DSR testing

The BBR test has received growing concerns regarding its applicability to field studies and special materials due to the large amount of long-term aged asphalt binder used in preparing asphalt binder beams and the time-consuming beam preparation and testing process. In recent years, the application of a dynamic shear rheometer (DSR) to investigate the low-temperature performance of asphalt binder has attracted widespread attention because it uses significantly less asphalt binder for testing and allows for easy specimen preparation. The objective of this study was to develop an efficient and robust method to evaluate the low-temperature performance of asphalt binder based on DSR testing. Frequency sweep tests were performed on twelve asphalt binders at temperatures ranging from 0 to 25 °C using the 8-mm parallel plate geometry. Two conversions were applied to frequency sweep test data in order to predict the flexural creep stiffness and m-value of asphalt binder, namely the conversion from frequency domain to time domain and the conversion from shear loading to bending loading. The 1S2P1D model was employed to construct the master curves of storage modulus and loss modulus. Afterwards, the flexural creep stiffness was predicted using the shear creep compliance master curve model, which was derived from the 1S2P1D model using the inverse Laplace transform, and the Poisson’s ratio, which was assumed to be constant. It was found that the predicted values of S(60) and m(60) were comparable to the counterparts measured by the BBR, which well demonstrated the feasibility of the proposed DSR-BBR conversion method. In comparison to existing analysis methods, the proposed conversion method strictly complied with the linear viscoelastic theory, and it enabled efficient and robust predictions because the prediction model of flexural creep stiffness had the same parameters as those of the 1S2P1D model, thus avoiding multiple data fittings.

Investigating the role of solvents in modulating glass transition and dynamic mechanical characteristics of polystyrene film

This study investigates how different solvents impact the glass transition and dynamic mechanical properties of polystyrene (PS) films. Using FTIR spectroscopy, it analyzes solvent-induced variations in molecular vibrations, particularly in the phenyl ring region. Results show solvent-specific effects on the 750 cm-1 peak, associated with the "meta-substituted aromatic ring," influencing phenyl ring vibrations. DSC analysis highlights solvent effects on the glass transition temperature (Tg), revealing complexities in PS films prepared with chloroform, tetrahydrofuran (THF), and toluene. Varied Tg behavior suggests solvent-driven structural modifications and gradual solvent removal. Dynamic Mechanical Analysis (DMA) demonstrates solvent-dependent changes in storage modulus, loss modulus, and tan δ, indicating solvent polarity role in polymer chain dynamics. Toluene-induced plasticization reduces Tg and increases creep compliance, revealing PS film sensitivity to solvents. These findings stress solvent selection importance in tailoring thermal and mechanical properties of polymer films for specific applications.

Failure behavior and probabilistic safety assessment of containment structure under internal pressure considering time-varying prestress loss

This paper adopts a refined method to calculate the prestress loss of containment and evaluates the impact of time-varying effects on the mechanical properties and safety of containment under accident pressure. Firstly, a new method for converting the commonly used creep model into the Kelvin chain creep model is proposed, and rate-type constitutive relationships considering time-varying factors are established. Utilizing the developed subroutine scripts, these constitutive relationships are incorporated into the ABAQUS platform. Subsequently, the prestress losses of containment at different service times are calculated. Finally, the failure behavior and the probabilistic performance of containment under prestress loss and internal pressure conditions are systematically discussed. Results show that the proposed method exhibits high applicability, and the fitted creep compliance function based on the Kelvin chain model agrees well with the original creep compliance function. For the investigated containment, the time-varying prestress loss is most pronounced in the horizontal tendons near penetrations. Under design pressure, the containment remains elastic for all investigated prestress loss conditions, but the structural deformation, steel liner strains, and principal tensile stresses in concrete increase with the increase in time-varying prestress losses. At the limit state, greater time-varying prestress loss makes the containment more prone to functional failure at lower internal pressures. The time-varying prestress loss has a significant impact on the fragility and reliability of the penetrations in containment, while its impact on regular segments is relatively small.

Study on the Storage Stability and Rheological Property of Bio-Oil/Lignin Composite-Modified Asphalt.

The objective of this study is to investigate the storage stability and rheological property of bio-oil/lignin composite-modified asphalt. The composite-modified asphalt with different proportions of bio-oil was prepared and cured at 105 °C, 135 °C, and 165 °C for 24 h and 48 h. The storage stability of the composite-modified asphalt was evaluated based on the softening point difference, the storage stability index derived from rotational viscosity, the segregation rate based on temperature sweep, and the non-recoverable creep compliance measured through the Multiple Stress Creep Recovery test. The storage stability of bio-oil/lignin composite-modified asphalt was evaluated through testing and analysis of its infrared spectroscopy and scanning electron microscopy before and after thermal storage. The research results indicate that the maximum difference in softening point is 0.9 °C, and the calculated storage stability index is generally below 0.1. The maximum value of the segregation rate is 0.43, indicating excellent storage stability of the bio-oil/lignin composite-modified asphalt. According to the results from infrared spectroscopy, no chemical reactions occurred during the storage process of the composite-modified asphalt. The scanning electron microscope confirmed that the samples became more stable after 48 h of storage.

Thermomechanical characterisation and plane stress linear viscoelastic modelling of ethylene-tetra-fluoroethylene foils

Ethylene-tetra-fluoroethylene (ETFE) is a polymer employed in tension membrane structures with mechanical properties that strongly depend on time and temperature effects. A comprehensive understanding of the mutual influence of these variables and a unified viscoelastic constitutive model design can enable wider exploitation of ETFE in sustainable lightweight construction. This study presents a thermomechanical characterisation of ETFE foils through quasi-static tensile experiments spanning two orders of magnitude of strain rates, creep, relaxation, shear and dynamic cyclic tests in a wide range of temperatures suitable for building applications, from −20∘ C\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$-20^{\\circ }\ ext{ C}$\\end{document} to 60∘ C\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$60^{\\circ }\ ext{ C}$\\end{document}. The experimental results in different material orientations are used to identify the limits of the linear viscoelastic domain, define the direction-dependent creep compliance master curves and calibrate the parameters of a plane stress orthotropic linear viscoelastic model, employing the Boltzmann superposition and the time-temperature superposition principles. The model has been numerically implemented using a recursive integration algorithm and its code is provided open source. A validation on independently acquired data shows the accuracy of the constitutive model in predicting ETFE behaviour within the linear viscoelastic regime usually adopted during structural design, with excellent extrapolation capabilities outside the range of the calibration data.

Physical aging of a glassy polymer in cultural heritage conservation

AbstractArtworks, particularly easel paintings, are multi‐component materials intended to last indefinitely. The protective coatings applied to these artworks often consist of amorphous glass‐like polymers, which undergo slow physical aging and structural recovery below their glass transition temperature. This process alters key physical properties such as mechanical strength, optical clarity, and thermal stability over extended periods. This study investigates the time‐dependent evolution of these properties in Laropal A81, a widely used synthetic resin for cultural heritage conservation, particularly as a replacement for ancient varnishes. The investigation involves characterization of enthalpy recovery via differential scanning calorimetry, refractive index evolution via refractometry, and creep compliance evolution via rheological measurements. The aging behavior of Laropal A81 is further analyzed using the Kohlrausch–Williams–Watts function and the Tool–Narayanaswamy–Moynihan model, enabling the quantification of critical dynamic parameters such as activation energy, nonlinearity, partition coefficients, and non‐exponentiality. The gained insights into the long‐term behavior of this coating's properties can be valuable for improving preservation and restoration strategies for cultural heritage.

Laboratory aging method for simulating the extracted aged asphalt from reclaimed asphalt pavement

This study compared the performance of extracted asphalt and laboratory aged asphalt. The five-year service asphalt mixtures were used for extraction in this study. The laboratory aged asphalt experienced the Rolling thin film oven (RTFO) aging the Pressure aging vessel (PAV) aging with variable duration (5, 10, 15, 20, and 25 hours). By comparing the softening point, viscosity, and rheological properties of both, an aging simulation protocol was established. For laboratory aged asphalt binder, the softening point increases by 3.56 %, 5.68 %, 7.43 %, 8.16 %, and 8.74 % at PAV aging times of 5 h, 10 h, 15 h, 20 h, and 25 h, respectively. The rutting index and viscosity of the aged asphalt gradually increases with the PAV duration. There is a substantial increase in creep recovery rate and a significant decrease in non-recoverable creep compliance for aged asphalt. The rheological aging index demonstrates a linear increasing trend. The sulfoxide (SO) and aromatic (CO) aging indexes of the laboratory-simulated aged asphalt progressively rise with prolonged PAV aging time. The SO and CO aging indexes of the extracted asphalt consistent with RTFO aged asphalt experienced PAV aging 20 and 25 hours. The extracted asphalt can be simulated in the laboratory under standard RTFO conditions and a 22.26 hours PAV duration at a pressure of 2.1 MPa ± 0.1 MPa. This study introduces a methodology for simulating asphalt aging in an authentic service environment by adjusting the laboratory aging test conditions.

Effect of biofilm physical characteristics on their susceptibility to antibiotics: impacts of low-frequency ultrasound

Biofilms are highly resistant to antimicrobials, often causing chronic infections. Combining antimicrobials with low-frequency ultrasound (LFU) enhances antimicrobial efficiency, but little is known about the underlying mechanisms. Biofilm physical characteristics, which depend on factors such as growth conditions and age, can have significant effects on inactivation efficiency. In this study, we investigated the susceptibility of Pseudomonas aeruginosa biofilms to tobramycin, with and without LFU treatment. The biofilms were grown under low and high fluid shear to provide different characteristics. Low-shear biofilms exhibited greater thickness, roughness, and porosity and lower density, compared to high-shear biofilms. The biofilm matrix of the high-shear biofilms had a three times higher protein-to-polysaccharide ratio, suggesting greater biofilm stiffness. This was supported by microrheology measurements of biofilm creep compliance. For the low-shear biofilms without LFU, the viability of the biofilms in their inner regions was largely unaffected by the antibiotic after a 2-hour treatment. However, when tobramycin was combined with LFU, the inactivation for the entire biofilm increased to 80% after 2 h. For the high-shear biofilms without LFU, higher LFU intensities were needed to achieve similar inactivation results. Microrheology measurements revealed that changes in biofilm inactivation profiles were closely related to changes in biofilm mechanical properties. Modeling suggests that LFU changes antibiotic diffusivity within the biofilm, probably due to a “decohesion” effect. Overall, this research suggests that biofilm physical characteristics (e.g., compliance, morphology) are linked to antimicrobial efficiency. LFU weakens the biofilm while increasing its diffusivity for antibiotics.

Verification of time-temperature superposition principle for viscoplastic strains of asphalt mixtures obtained from creep-recovery tests in the low-strain regime

The creep compliances, total, and viscoplastic (VP) strains of various asphalt mixtures were determined from creep-recovery tests at different temperatures to construct their master curves. In order to ensure the reliability of the obtained results, the agreement between quantities in the time and frequency domain as well as sources of bias in testing were investigated. A viscoelastic and a VP model were used to respectively characterise the reversible and irreversible deformation of the materials. The behaviour of the specimens exerted by a constant stress at various temperatures were then predicted using independent values of the viscoelastic and VP reduced times. Owing to the good agreement between prediction and measurement, the time-temperature superposition principle in the VP domain was verified. In general, the shift factors were uncorrelated with each other. However, at elevated temperatures, the gaps between them became unimportant, enabling the extension of viscoelastic shift factors into the VP domain.

Fatigue cracking prediction of RIOHTrack full-scale test track based on variable-order fractional Burgers model

We propose a modified thermal cracking (MTC) model in this paper, which utilizes the evolution of crack propagation to predict the number and density of cracks that will form on the RIOHTrack full-scale test track. We incorporate the variable-order fractional Burgers model as an important component of the thermal cracking (TC) model, for calculating the creep compliance. Furthermore, we apply the Levenberg–Marquardt (LM) algorithm as a data-driven approach, for parameter fitting. The MTC model is constructed technically through creep compliance approximation compute and parameter fitting as follows. First, we employ the variable-order fractional Burgers model to calculate the asymptotic creep compliance of each pavement segment within the RIOHTrack full-scale test track. More precisely, we derive the explicit asymptotic expansion of creep compliance based on the variable-order fractional Burgers model. Such an asymptotic expansion represented by the Gamma function is a simplified representation of the creep compliance, and it ensures that the fitting accuracy R2 is greater than 0.87. Parameter fitting of the creep compliance is based on the RIOHTrack full-scale pavement test data, using the LM algorithm. Then, the creep compliance in the original TC model is mathematically upgraded to the above variable-order fractional approximation form, and parameters in the MTC model are numerically estimated using the LM algorithm based on prior knowledge from the RIOHTrack test data. Our prediction analyses based on the RIOHTrack data demonstrate the superior performance of the proposed MTC model.