Journal of Materials in Civil Engineering

Ultrahigh-performance fiber-reinforced concrete (UHPFRC) features outstanding durability properties in uncracked state, although its composition based on very low water/cement ratios may result in a higher risk of early-age cracking due to increased shrinkage. This paper, based on research performed in the framework of the H2020 project ReSHEALience, studied aggressive chemical exposure conditions. A UHPFRC reference mix with 0.8% crystalline admixtures (CAs) and two other mixes, one containing 0.25% alumina nanofibers (ANFs) and one containing 0.15% cellulose nanocrystals (CNCs), both by weight of cement, were investigated. This study analyzed the synergy between CA and the nanoconstituents (ANF and CNC) on the physical, chemical, mechanical, and durability properties the and self-healing capacity of uncracked and cracked UHPFRC. The results showed that the presence of nanoadditives improves the mechanical properties independently of environmental curing conditions, refines the pore structure, favors cement hydration, and improves the intrinsic durability with a Cl and water transport reduction. Moreover, in the cracked state, nanoconstituents improved the self-sealing and self-healing capacity of specimens immersed in geothermal water.

This study aims at analyzing the influence of agroindustrial waste incorporation into red ceramics to produce lightweight aggregates sintered in a microwave oven. Sustainable artificial lightweight aggregates are sought out, particularly in the context of a circular economy. At first, red clay, sugarcane bagasse ash, and rice husk ash were characterized by means of X-ray fluorescence, loss on ignition, X-ray diffraction, grain sizing, true specific mass, and thermal gravimetric analysis. Three different ceramic masses were extruded: the reference, with no added waste; clay with 40% sugarcane bagasse ash; and clay with 40% rice husk ash. All samples were presintered in a conventional oven at 600°C for 60 min. Conventional sintering occurred at temperatures between 700°C and 1,100°C at a $10°\mathrm{C}/\min$ heating rate. Microwave sintering occurred for 5, 10, and 15 min, at a $50°\mathrm{C}/\min$ heating rate in a chamber coated with silicon carbide (susceptor). After sintering, specimens were characterized regarding linear shrinkage, water absorption, apparent porosity, apparent specific mass, X-ray diffraction, and scanning electron microscopy. Results showed that microwave sintering increased compressive strength, decreased water absorption, and provided microstructure refinement. The addition of waste reduced specimens’ specific mass after sintering. Sugarcane bagasse ash–added red ceramic specimens sintered in a microwave oven yielded values close to those of Brazilian expanded clay, thus appearing as an alternative for production of more sustainable lightweight aggregates, in view of greater agroindustrial waste utilization and lower energetic consumption during the sintering process.

Textile-reinforced concrete (TRC) is a special type of concrete gaining popularity nowadays in the field of civil engineering due to its technical advantages. Owing to the absence of coarse aggregate and high paste content, the properties of TRC are different from conventional concrete. Further, for the same reason, the characteristics against aggressive environmental conditions are different for TRC. As TRC can be used in many applications subjected to aggressive environments, in the present work, the mechanical and durability characteristics of TRC against acidic and alkaline environments are studied. The effect of the thickness of TRC specimens is also studied by using specimens of varied thicknesses such as 10, 15, and 20 mm. Compressive and flexural behavior tests for mechanical properties and water permeability as well as weight loss tests for durability characteristics are conducted. The results obtained showed that there is no significant weight loss due to the exposure to acidic or alkaline environments. However, there is a change in the compressive and flexural behavior of the TRC specimens subjected to various pH. This shows that the material can perform differently for strength and durability properties, as durability is mainly concerned with the density/permeability of the concrete whereas the strength depends on many other factors. Further, it is concluded that the increased thickness reduces the impact of aggressive solutions on TRC.

Waste-cooking oil (WCO) has received significant attention regarding rejuvenating aged-asphalt binder (AB) in recent years. Most current studies focused on whether the performance of WCO rejuvenated aged-asphalt binder (WRAB) can meet the requirements without considering the susceptibility to performance change after the reaging process (secondary aging). To evaluate the performance of WRAB under real pavement conditions, this study first evaluated the rejuvenation effect of WCO from the three perspectives of basic physical, rheological, and chemical characteristics. Then, WRAB was secondary aging carried out to evaluate the aging resistance from the rheological and chemical characteristics compared with virgin asphalt binder (VB). The basic physical properties were based on penetration, softening point, ductility, and rotational viscosity. The rheological characteristics consisted of temperature sweep, frequency sweep, linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests. The chemical analysis was composed of Fourier transform infrared spectrometry (FT-IR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) analysis. The results indicated that the basic physical properties of AB could be rejuvenated to the level of VB. The WCO had a better effect in rejuvenating low-temperature than high-temperature performance. After secondary aging, WRAB had better rutting resistance and lower phase angle compared with VB. The WRAB had lower yield stress but higher fatigue life—more suitable for light traffic roads—and the WCO could decrease the strain sensitivity of the WRAB. After secondary aging, WRAB had better aging resistance in fatigue life. According to the DSC results, WRAB had better low-temperature performance after secondary aging. Based on the weighted average molecular weight ($M_w$), WRAB had a larger molecular weight to secondary aging. A good correlation existed between $M_w$ and rheological parameters for the WRAB after secondary aging.

Pumping of concrete is an efficient placement technique. When the concrete is pumped in a pipe, the lubrication layer (LL) forms and its rheological properties predominantly dictate the flow and govern the resumption operations. The primary purpose of this study was to investigate the effects of a new admixture, limestone calcined clay (${\mathrm{LC}}^2$) at variable replacements (0%, 5%, 10%, and 20% by weight) on rheological properties of cementitious suspensions (equivalent to lubricating layer). An increase in yield stress, plastic viscosity, structuration rate, and decreased percolation time were observed with increments in the proportion of ${\mathrm{LC}}^2$ in cementitious suspensions. However, at the optimal dosage of superplasticizer, yield stress and plastic viscosity were decreased by 78% and 82%, respectively, even for the maximum replacement (20%) of ${\mathrm{LC}}^2$. Similarly, the percolation time increased by 15% and the structuration rate decreased by 39%, allowing additional time to deal with any pumping operational delays. From the results, it is also evident that higher deformation ratio of the lubrication layer is beneficial for concretes at rest due to pumping interruption. This study contributes to the fundamental understanding of viscoelastic properties of ${\mathrm{LC}}^2\text{-}\text{based}$ cementitious suspensions, which will improve understanding of lubrication layer behavior for pumping operations.

With the development of the highway industry and new materials, long-afterglow luminescent material as a new energy storage and environmental protection material has gradually been applied to night lighting. In this study, ${\mathrm{SrAl}}_2{\mathrm{O}}_4:{\mathrm{Eu}}^{2+}$, ${\mathrm{Dy}}^{3+}$ long-afterglow materials were prepared by the solid-state reaction method. The luminescent properties were improved by changing the process parameters. The single-factor test results indicated that the luminescent properties were highest when flux content, calcination temperature, calcination time, and doping ratio of Eu and Dy were 5%, 1,300°C, 2 h and $1:1$, respectively. Then, long-afterglow materials with high luminescence were prepared by adding a pore-forming agent. The structural characteristics and optical properties of the products were analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis indicated that the addition of pore-forming agent did not change the crystal structure of the material but changed the surface morphology of the long-afterglow materials. The surface morphology of the products changed from flat and dense to a convex structure after adding pore-forming agent, and some connected pore structures were produced. The afterglow performance of products was continuously improved with the increase of pore-forming agent content. Finally, luminescent coatings were prepared by combining with fluorine-containing resin, and the performance was studied. The stability of luminescent coatings decreased with the increase of the filler:binder ratio, and the best ratio was $0.5:1$. The luminous performance of coatings was best when the amount of long-afterglow phosphor was 40%. The luminescent coatings had good adhesion with the road surface, and the luminescence could last for more than 7 h in a dark environment.

As the most important infrastructure of the airport system, airfield pavement is exposed to the challenges with heavy aircraft loads and increased flight frequency. Therefore, its preservation and maintenance has been imperative. Fog seal was one of the most cost-effective approaches to solve the problem of early-stage damage and extend the service life of airport pavement. However, the traditional emulsified asphalt tended to present inadequate mechanical strength and would cause a temporary friction loss on pavement, even if polymer modification had been conducted. In this research, the application of thermosetting materials with modified asphalt emulsion, including waterborne epoxy and acrylate, was investigated as a preventive maintenance material for airport pavement. First, the storage stability was tested to study the compatibility. Then, the chemical reactions during the curing process of thermosetting materials in asphalt emulsion were observed by Fourier transform infrared (FTIR). The binder bond strength (BBS) test was conducted to evaluate the adhesion strength evolution of asphalt emulsions. The British Pendulum and pavement permeability tests were carried out to analyze the impact of waterborne additive on pavement skid resistance and permeability in terms of different sand contents. The abrasion resistance was measured by wet track abrasion tests. The thermosetting structures in residues were observed with the fluorescence microscope, and statistical analysis was conducted finally. The results revealed that waterborne epoxy and acrylate, as waterborne thermosetting modifiers, had high potential to be applied in fog seal technology for airport pavement.

The drying shrinkage of alkali-activated concrete (AAC) is a very complex process, and it warrants long-term testing. The present study was focused on the development of drying shrinkage prediction models for ambient-cured AAC. AAC with four distinct precursor combinations for experimental validation and investigation of the influence of mix proportions were used. The applied fly ash (FA) to ground granulated blast-furnace slag (GGBFS) ratio was varied as 100:0, 70:30, 60:40, and 50:50. Drying shrinkage strains were determined for hardened paste, mortar, and concrete specimens. The observed drying shrinkage behavior was correlated with the mineralogical, chemical, and morphological characteristics of corresponding paste specimens of alkali-activated binder (AAB). These characteristics were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), respectively. The results showed that the drying shrinkage of hardened AAB paste and AAB mortar increases by 26%–32% and 13%–28% with GGBFS content, respectively. The qualitative and quantitative microstructural analysis suggested that this behavior could be ascribed to the formation of a calcium aluminosilicate hydrate matrix. Moreover, FA-based AAC exhibited maximum shrinkage, probably due to its comparatively high overall porosity with the addition of both coarse and fine aggregates. Using the experimental data, stepwise linear and multivariate nonlinear regression models were developed by modifying existing portland cement concrete (PCC) models to predict the drying shrinkage strains of AAC. Recommended linear and nonlinear regression models were selected based on the least deviation from the experimental value. The modified GL2000 model was found to be the best fit for shrinkage predictions in AAC because of its simplicity and comparable precision to experimental findings.

Abundant crushed pebbles are used as substitutes for high-quality aggregate to solve the shortage of asphalt pavement aggregate in Tibet. However, since crushed pebbles belong to acid aggregates with a smooth surface, the adhesion between them and asphalt binder and its improvement measures need further study. Thus, the solvent elution method was used to verify the adhesion between the asphalt binder and various aggregates, and the microscopic changes of the eluted asphalt binder were analyzed by Fourier transform infrared (FTIR) and gel permeation chromatography (GPC). The results show that the freeze-thaw splitting strength ratios of various asphalt mixtures with crushed pebbles were all above 80%. The addition of mineral powder enhanced the absorption from resins and asphaltenes in the aggregate’s surface. Also, the joint action of cement and antistripping agent improved the absorption capacity of aggregates to molecules. Furthermore, there was a significant correlation ($\mathrm{r}>0.5$) between the weight average molecular weight and performance indexes of asphalt mixture, indicating that the solvent elution method has certain guiding significance for the study of adhesion between the asphalt binder and aggregate.

The alkali-silica reaction (ASR) has been recognized as a major distress in concrete for nearly a century. In the US, ASR is a major cause of the deterioration of highway concrete structures (i.e., bridges and pavements). A research study was recently undertaken in the state of Idaho to evaluate the advantages associated with implementing the miniature concrete prism test (MCPT) from current standards for various reactive aggregates. A total of 11 different aggregate materials (both coarse and fine fractions), including a nonreactive reference aggregate, were collected from various sources and tested using the 56-days MCPT as well as the commonly used accelerated mortar bar test (AMBT). In addition, selected aggregate samples were tested using the 1-year long concrete prism test (CPT) and the 6-month accelerated concrete prism test (ACPT). The results demonstrated that the 56-day MCPT method resulted in higher percent expansion compared with the 14-day AMBT and 1-year CPT methods for the fine fractions of the test aggregates. The coarse fractions of the test aggregates, on the other hand, exhibited a lower percent expansion during the 56-day MCPT compared with the 14-day AMBT. Overall, the MCPT test results were found to correlate well with the 14-day AMBT and 1-year CPT test results. In addition, the 6-month ACPT method showed similar results to the ones of the 1-year CPT method, with high correlation between both methods. Recommendations were made based on the findings from this study to facilitate the implementation of the MCPT into practice by state and local highway agencies for better assessment of the ASR potential of aggregates.

At present, prestressed structures are widely used in offshore buildings and bridges. After corrosion, the prestressed structure’s mechanical properties decline, significantly reducing the structure’s bearing capacity and threatening the prestressed system’s safety. Therefore, it is necessary to study the variation of mechanical properties of corroded prestressed strands. In the past, researchers mainly studied the rusty prestressed strands in the state of no stress, which is different from the prestressed strands in the actual structure. It can provide many benefits to study how the strain level affects the corrosion of prestressed strands. In this work, the mechanical properties of corroded prestressed steel strands under different strain levels were tested by experiment. The results show that the existence of strain will increase the corrosion amount, but the effect of strain on the corroded strand’s mechanical properties is not uniform. The mechanical properties of strands decrease linearly with increase of corrosion amount, but the dispersion is large, so the probability method is more suitable. The probabilistic prediction model of corroded strands’ mechanical properties is proposed in this paper, and the prediction results are compared with the experimental results. The prediction results are consistent with the test results, and the range of prediction results is narrower than the test results. But the prediction result of elongation does not align well with the experimental work.

In this study, the mutual effect of polyphosphoric acid (PPA) and ethylene bis(stearamide) (EBS) modification was examined on the high and low service temperatures and viscosity of a performance grade (PG) 58-22 asphalt binder as a conventional neat bitumen widely used for paving applications. Three different dosages of PPA, including 0.5%, 1.0%, and 1.5% were used to modify the neat asphalt binder, and 3% of EBS as a selected percentage was added to PPA-modified samples. The dynamic shear rheometer was used to evaluate the high-temperature properties of the neat and modified bitumens based on standard Superpave protocol parameter (${\mathrm{G}}^{*}/\sin \delta$) and multiple stress creep and recovery test. The low service temperatures of the samples were determined using the bending beam rheometer test. Also, the high-temperature ranges viscosities of the samples were evaluated using a series of rotational viscometer tests. The results have shown that increasing the PPA dosage up to 1.5% enhances the high service temperature of the neat asphalt binder 20.4°C and 14.7°C based on Superpave protocol and multiple stress creep and recovery test, respectively. However, it deteriorates the low-temperature performance of modified binders from $-24.3°\mathrm{C}$ to $-16.9°\mathrm{C}$. The EBS can significantly compensate for the negative effect of PPA modification on the low-temperature behavior of modified bitumens. The optimum combination was 1% $\mathrm{PPA}+3\%$ EBS as it provides a similar low-temperature grade to the neat asphalt binder having a significant two grades enhancement of high service temperature. Modifying a PPA-modified asphalt binder with EBS can reduce its viscosity at high temperatures, leading to saving energy of mixing and compaction.

Biobased green plasticizers are preferred in the production of plastics in light of the environmental and human health issues posed by traditional plasticizers. Epoxidized soybean oil is an environmentally friendly admixture that is a significant alternative for biobased polymer concrete rather than petroleum-derived products such as polyethylene terephthalate, rubber, and polyvinylchloride. This study aims to determine the effect of epoxidized soybean oil additives on cement paste properties, and to compare the effects of epoxidized soybean oil and dioctyl terephthalate on cement paste properties. With the addition of 10% epoxidized soybean oil to cement paste, electrical resistance was 1.91 times higher, and thermal resistance was 1.70 times higher, than the control sample, while water absorption and porosity decreased by $65\%\pm 4.0\%$. Compared to dioctyl terephthalate-impregnated cement pastes, epoxidized soybean oil cement pastes have higher values for calcium hydroxide content and ultrasonic pulse velocity ($91\%\pm 0.3\%$ and $182\%\pm 2.0\%$, respectively), and lower values for porosity and thermal conductivity ($30\%\pm 3.0\%$ and $16\%\pm 0.1\%$, respectively). Moreover, epoxidized soybean oil can form three times more hydrogen bonds than dioctyl terephthalate, which allows for the formation of less porous and more compact cement pastes.

Aggregates are the major constituents of concrete in terms of volume; therefore, they strongly affect concrete’s strength and durability. Coquina is one of the most abundant carbonate rocks found along the coastal area of the Persian Gulf, and due to its high porosity and low mechanical properties, is not generally used as concrete aggregate. This study aims to investigate the effect of limestone, travertine, and coquina aggregates on the physico-mechanical properties and durability of Portland concrete (PC) and sulfur concrete (SC). The durabilities of the formulated concretes were studied in different chemical solutions and different marine environments of the Persian Gulf. It was found that SC has higher strength and elastic modulus and lower effective porosity and water absorption compared to the PC made by the same type of aggregates. In PC, limestone and travertine gained a higher uniaxial compressive strength due to their lower porosity and higher physical properties than coquina. However, in SC, coquina, due to its high porosity, allowed SC to penetrate the pores and induce better adhesion. Therefore, coquina makes stronger SC than limestone and travertine. Laboratory aging test results show that SC has higher resistance against aging tests than PC made by the same aggregate types. Due to the higher strength and lower effective porosity and water absorption, the SC made by coquina was the most durable in artificial aging tests and different marine environments. Those SC placed in the tidal zone had the highest loss in strength and those placed in the submerged zone showed the lowest change in strength. Furthermore, due to the salt weathering, wetting-drying cycles, wave effects, and temperature differences in environments such as tidal zones, more care should be taken using SC. This study showed that it is possible to make concrete with acceptable physico-mechanical properties with weak aggregates such as coquina by changing the cement type.

Crumb rubber is one of the waste materials used to improve the behavior of binders. The use of this recycled rubber as a common cheap additive can also help in preserving the environment. Modifying the binder with this additive can consequently increase its viscosity. The primary aim of this research is to identify the factors that influence the viscosity of the crumb rubber–modified binders and determine their optimal values by modeling the viscosity of the samples. To this end, central composite design (CCD) method of response surface methodology (RSM) was utilized to evaluate the influence of the selected factors including mixing temperature, time, speed, and blending content of the modifier on the viscosity of the crumb rubber–modified binders, which was identified as the main response. Based on the CCD method, 30 samples were prepared, and a rotational viscosity (RV) test was conducted on them. The results showed that crumb rubber content and mixing temperature are more effective than the other factors and their interactions. To yield the minimum viscosity, the optimal values for the influential factors were 4% for the blending content of the crumb rubber, 160°C for the mixing temperature, 57 Hz for the mixing speed, and 35 min for the mixing time. In this optimal case, the results of Fourier-transform infrared (FTIR) spectrum analysis showed that adding crumb rubber to the neat binder does not create a new factor group in the binder spectrum.

There is strong demand for ductile cement-based materials in various rehabilitation systems of concrete infrastructure. This study investigated the flexural performance of nanomodified cementitious composites incorporating a novel class of basalt macrofibers, basalt-fiber pellets (BFP), in an overlay system. The cementitious composites comprised 50% fly ash or slag replacement with 6% nanosilica and 4.5% BFP. The cementitious composites [top (overlay) layer] were evaluated based on mechanical compatibility with intact and precracked concrete substrate (bottom layer) through flexural loading. In addition, three-dimensional finite-element models were established for these configurations to analyze the effect of overlay thickness and substrate compressive strength on the performance of the overlay systems. The results showed effective bonding of the composites with the substrate (without transverse delamination) and highlighted their contribution to enhancing the postcracking performance of the overlay system, in which the intact system of Specimens N-F-4.5 and N-G-4.5 had toughness 324% and 471%, respectively, higher than that of reference concrete specimens. Numerical analysis showed the influence of overlay thickness on the ductility of both systems (intact and precracked), whereas the substrate strength affected only the first-cracking strength of the intact system (approximately 25%, increasing the compressive strength of the substrate concrete from 40 to 50 MPa).

Mass ply panel (MPP) is a new mass timber product that was recently introduced for structural applications in buildings. Although there have been several studies on characterizing the mechanical properties and structural performance of MPP, there is a lack of understanding regarding in-plane shear properties of the panels. More intensive studies should be done for MPP to provide a comprehensive understanding of its behavior. This paper presents an experimental study to characterize the effective in-plane shear modulus and shear strength of MPP in the major strength direction of the panel. Two experiments, including multiple span-length center-point bending tests and a novel large-scale shear test, were conducted. The test results were presented and compared with previous studies and the manufacturer’s product report. The new test proposed for shear strength characterization has the potential to be an industry standard for mass timber panels.

Pavements covered with snow and ice in winter will reduce antiskid performance, which may cause harm to road operation safety. In this study, an asphalt mixture containing a low-freezing-point additive (LFPA) was developed for pavement applications, and its antifreezing properties were evaluated experimentally. Eight kinds of porous materials including volcanic rock, fly ash, zeolite, diatomite, and modified diatomite were selected as carriers. The optimum salted carrier and surface modifier and the preparation conditions of LFPA were studied by conductivity test, rapid determination of chloride ion test, laser size distribution apparatus (LSDA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The asphalt mixture containing LFPA by volume displacement method was prepared by the Marshall test, and its pavement performance and antifreezing properties were evaluated. The results showed that modified diatomite (ground for 10 min) exhibits high chloride adsorption capacity, and Span 60 (Sorbitan Monostearate) is the optimum surface modifier of the coated carrier. The ratio of surface modifier and carrier salt is $1:5$, and the modification temperature of surface modifier is 80°C. Moreover, when the mineral fillers in the styrene-butadiene-styrene (SBS) asphalt mixture are partially replaced by the LFPA, the rutting resistance increases at first and then decreases, and low-temperature stability and water stability decrease with increasing LFPA content. Finally, the deicing performance evaluation showed that the ice-melting ratio can be significantly improved by adding LFPA to the mixture. At a content value of sustained-release LFPA of 20%, the ice-melting ratio was maximized.

India is witnessing unprecedented growth in its road network. To meet the asphalt binder demand, distillation towers have been loaded with crude oil from different sources. Although the quality system is expected to guarantee reduced variability, a quality system based on traditional indexes may lead to high variability in binders of the same grade. Because India relies on traditional indexes for quality control, we aimed to quantify such variability and its impact specifically on moisture damage resistivity. Additionally, the response of binders from different sources in the short term and long term has also been evaluated. Five binder sources were selected, and they were meant to conform to the same viscosity grade. Thereafter, moisture damage assessment tests such as surface free energy (SFE) measurements, bitumen bond strength (BBS) test, rolling bottle test (RBT), and boiling water test (BWT) were performed in unaged, short-term aged, and long-term aged conditions. Additionally, variations in chemistry of the binders were assessed based on Fourier transform infrared (FTIR) spectroscopy. It was concluded that the chemical and moisture damage characteristics had a strong dependence on the source of the binder. Furthermore, there was substantial variability in the moisture damage performance for binders from different sources. This implied that quality systems based on traditional indexes may not be stringent enough to reduce the variability. The impact of aging on the moisture damage resistivity of the asphalt–aggregate system was also discussed. Given the limited information available in the literature on asphalt binder variability of the traditional grading system, the data reported in this study can serve as reference for future studies dealing with its characterization and assist in developing a strategy for reducing uncertainty related to the performance of asphalt mixes.

Research on the aging process of styrene-butadiene-styrene block copolymers (SBS) block copolymers modifier has practical significance in guiding the recycling of SBS-modified asphalt pavement. The objective of this study is to investigate the aging process of SBS modifier under various oxygen and thermal conditions to address the variations of physical properties and chemical reaction during the service life of recycled asphalt pavement (RAP). In the proposed testing process, SBS modifier was thermal oxidative and vacuum thermal aged at different temperatures and time prior to blending with base asphalt to prepare SBS-modified asphalt. SBS modifier was first dissolved by carbon tetrachloride (${\mathrm{CCl}}_4$) and then tested through infrared (IR), gel permeation chromatography (GPC), and thermogravimetric (TGA) tests to investigate the variations on microstructure and chemical compositions of aged SBS modifier. The effect of aged SBS modifier on performance of SBS-modified asphalt was evaluated by comparing the mechanical and chemical properties of base and SBS-modified asphalts. Based on the results of the experimental program, appearance variation, modifying effects, and chemical reaction of SBS modifier under oxygen condition were obviously different from that of vacuum condition. The chemical reaction of SBS modifier was not significant at vacuum and high temperature condition, instead, a small amount of degradation was observed. Degradation of mechanical performance of SBS-modified asphalt was mainly caused by aging of base asphalt. Therefore, the SBS modifier in the RAP was suggested to be considered in the mixture design.

Styrene-butadiene-styrene-modified asphalt binder (SBSMA), crumb rubber–modified asphalt binder (CRMA), and high-viscosity-modified asphalt binder (HVMA) have been widely used in porous asphalt concrete. However, the aging of the modified asphalt binder significantly affects the performance of the porous asphalt concrete. The main aim of this research is to quantitatively assess the aging degree of finished product–modified asphalt binders of SBSMA, CRMA, and HVMA at high, medium, and low temperatures, and to explore the aging mechanism at the microscopic level. This study used rolling thin-film oven and pressurized aging vessel to simulate the aging of asphalt binders. Dynamic shear rheometer, bending beam rheometer, Fourier transform infrared spectrometry, thin-layer chromatography with flame ionization detection, and scanning electron microscopy were employed to investigate how aging affects the rheological and microscopic properties of finished product–modified asphalt binder. The results showed that at high temperatures, short-term aging significantly impacted HVMA [change rate of the rutting factor $(\mathrm{CRRF})=18.9\%$], while long-term aging had an enormous influence on CRMA ($\mathrm{CRRF}=179.5\%$). Short-term aging had the greatest effect on the fatigue property at medium temperature of CRMA [change rate of $N_f$ $(\mathrm{CR}{N}_f)=59.9\%$], followed by SBSMA ($\mathrm{CR}{N}_f=46.1\%$) and HVMA ($\mathrm{CR}{N}_f=26.2\%$). However, the effect of long-term aging on the fatigue properties of HVMA ($\mathrm{CR}{N}_f=99.2\%$) is the largest, followed by that of CRMA ($\mathrm{CR}{N}_f=95.8\%$) and SBSMA ($\mathrm{CR}{N}_f=56.6\%$). At low temperature, compared with CRMA and HVMA, aging had the greatest influence on the low-temperature rheological properties of SBSMA. In addition, the three finished product–modified asphalt binders exhibited similar changes in microscopic level after aging.

The asphalt modifier formed by the miscibility of waste cooking oil and rubber is referred to as WRO. WRO modifiers prepared from waste tire crumb rubber (WTCR) and waste cooking oil (WCO) have the potential for solving the problems of segregation of rubber asphalt and the low recycling rate of waste cooking oil. The results of the Cole-Cole curve show that the WRO modifier can remarkably enhance the miscibility of WTCR and base asphalt. The Fourier transform infrared spectrometer (FTIR) tests proved that WTCR, WCO, and base asphalt were mainly physically miscible during the preparation of the WRO modifier and modified asphalt. In the process of preparing the WRO modifier and modified asphalt, the rubber undergoes devulcanization, conjugated double bond reduction, and oxidation reactions. The WRO modified asphalt presents great workability, storage stability, high-temperature elastic recovery, low-temperature crack resistance, and deformation recovery ability. In addition, the results of the multiple stress creep and recovery (MSCR) tests present that the WRO modified asphalt has desirable antirutting properties. The optimal preparation process of the WRO modifier preferred by orthogonal design is stirring 0.5 h at 260°C, and the mass ratio of WTCR and WCO is $6:4$.

The mechanical performance of cementitious materials can be improved by incorporating carbon nanotubes (CNTs). Nevertheless, some challenges must be overcome, such as reducing the agglomeration trend of CNTs and minimizing their negative effect on the fresh state of the cementitious matrices. In this study, early-age portland cement (PC) hydration and the rheological behavior of cementitious composites with nonsilanized, 3-aminopropyltriethoxysilane (APTES)-functionalized CNTs were investigated. The APTES-functionalized CNTs were incorporated into PC pastes in contents of 0.05% and 0.1% by cement weight. The rotational rheometry of the CNT cementitious composites was carried out during the first hour of hydration. The effect of CNT silanization on cement hydration was assessed using isothermal calorimetry and in situ X-ray diffraction (XRD) for 48 h. The functionalization of CNTs with APTES offset the negative effect of nonsilanized CNTs on the fresh properties of the cementitious matrix, reducing the dynamic yield stress up to 39%. Calorimetry and in situ XRD results revealed that nonsilanized CNTs hindered early cement hydration, while the APTES-treated CNTs allowed proper hydration. At 28 days, the XRD and thermogravimetric analysis (TGA) results indicated that nonsilanized and silane-treated CNTs showed an equivalent hydration degree compared to the plain cement paste. Overall, CNT silanization improved the early age performance of cement pastes, enhanced the fresh properties of cement pastes, and did not affect the early hydration of PC.

Gradation information can be really useful when evaluating the performance of pavement, especially when the local climate condition or traffic volume have special requirements on gradations of asphalt pavement. However, due to poor management or long construction time, it may be difficult to accurately acquire the asphalt gradation type on site. To solve this problem, this study aimed to analyze the grading characteristics of both asphalt concrete (AC) and stone matrix asphalt (SMA) mixtures through statistics and to propose a quantitative indicator that could distinguish them rapidly. Methodologically, passing rate difference (PRD) between two adjacent sieve sizes was used to characterize the gradation and to distinguish AC from SMA. Five sieve sizes were considered in this study, namely, 16 mm, 13.2 mm, 9.5 mm, 4.75 mm, and 2.36 mm, and four PRDs were computed and analyzed. A total of 854 sets of gradation data were collected from 437 papers. To study the influence of nominal maximum particle size (NMPS), the data were further categorized into three types, namely, gradation data with NMPS of 16 mm, 13 mm, and regardless of NMPS. As a result, in all cases of NMPS, critical PRDs were determined to distinguish between SMA and AC mixtures. Moreover, when a critical PRD was determined, for a given gradation, the confidence level to correctly identify an AC gradation was generally higher regardless of NMPS.

Modern concrete construction consumes significant amounts of freshwater, which is a valuable natural resource. Using seawater can be an alternative solution to reduce freshwater consumption for sustainable development. The durability of seawater construction materials should be studied for better understanding of their long-term behavior. This study investigated the effect of seawater on the hydration and the sulfate resistance of noncement mortars prepared by mixing ground granulated blast furnace slag (BFS), carbide slag (CS), and silica fume (SF) to understand the feasibility of using seawater and solid waste materials to develop low-carbon construction materials. CS in the mix acted as an alkali activator for the hydration and strength development of the solid wastes. Two batch specimens were prepared, one batch mixed with seawater and the other mixed with freshwater for comparison. A compressive test investigated the effect of seawater on the mechanical properties. Heat flow, X-ray diffractometry (XRD), and thermogravimetry tests were used to understand the hydration. The results suggest that the seawater could accelerate the hydration by producing a large amount of hydrocalumite, which improves the compressive strength at early ages. Durability testing was carried out by immersing specimens in a sulfate solution for various durations. Sulfate resistance was characterized by XRD, and ettringite and Friedel’s salt were the main corrosion products when the specimens were immersed in sulfate solution. Corrosion could be reduced by seawater in the specimens. Scanning electron microscopy was used to characterize the microstructure of the hydration products, which showed that the corrosion was a progressive process. A loose and porous microstructure of the specimen surface accelerated corrosion of the noncement specimens.

Fillers are known as dust fractions in asphalt mixes having a predominant particle size less than 75 micrometer (μm). Typical filler concentration in an asphalt mix varies from 4% to 12% (by aggregate weight). The effects of filler intrinsic properties on mastic behavior can get magnified with the concentration of filler. Thus, in filler-rich mixes like stone matrix asphalt (SMA), the filler characteristics and concentration can be sensitive factors, playing significant roles in the performance of asphalt mastic and mix. The study considered six different types of fillers to capture the effect of filler characteristics on mastic. The mastics were prepared with a constant filler concentration by volume ($F/B_{\mathrm{vol}}=0.49$), which was determined by a typical SMA mix design. The fillers were characterized based on their surface area, size distribution, shape, Rigden voids (RV), clay content, and chemical composition. The filler effects on mastic were evaluated based on the stiffness (complex modulus) and stiffness ratio. The weak correlation observed between the mastic stiffness and the fixed and free binder reveals that the RV and filler fixing factor (FFF) can mislead regarding the stiffening potential of filler material. The surface areas by Brunauer–Emmett–Teller (BET) and Blaine’s methods were insufficient to represent the stiffening potential while the stiffness showed a better correlation with the concentration of finer gradations in the filler evinced by a higher coefficient of ${\mathrm{P}}_{10}$ (percentage passing 10 μ sieve size) and fineness modulus (FM) parameters. Further, the micromechanics based understanding of mastic behavior explains the mastic stiffening phenomenon as the combined effects of adsorbed asphalt layer thickness and interparticle interaction. The linear relation observed between stiffness ratio and newly derived micromechanism stiffening factor (MMSF) indicates that in filler-rich mastics, the stiffness may be improved with a finer sized filler (lower FM) and higher volume concentration. However, the adsorbed layer thickness didn’t show correlation with any of the filler properties considered. The study recommends a limiting value for mastic stiffness in terms of stiffness ratio which is established based on MMSF factor. A limiting value for stiffness of mastic could be significant to avoid dry mixes and subsequent poor fatigue performance.

This study investigated the frost resistance of fiber-reinforced concrete with different contents of polyvinyl alcohol (PVA) fiber under freeze–thaw cycles, and the resistance to chloride penetration. The freeze–thaw cycle experiment was carried out using the rapid freeze–thaw method. Mass loss, relative dynamic modulus of elasticity, compressive strength, and flexural strength were investigated, and the influence of chloride ion content and the chloride ion diffusion coefficient after freeze–thaw cycles was analyzed. The results showed that under freeze–thaw cycles, PVA fiber can effectively reduce mass and dynamic elastic modulus loss and improve compressive and flexural strength. The contributions of fiber to mass loss, relative dynamic elastic modulus, and compressive strength gradually decreased with the addition of PVA fiber ($>0.12$ vol. %), while the contribution to flexural strength increased. The penetration depth of chloride ions positively correlated with the number of freeze–thaw cycles. The PVA fiber-reinforced concrete exhibited better chloride ion penetration resistance compared with that of the control concrete after freeze–thaw cycles. The concrete mixed with 0.12 vol. % PVA fiber exhibited the best chloride ion penetration resistance.

To compare the aging behavior of asphalt before and after short-term aging, the rolling thin-film oven test (RTFOT) was used to conduct short-term aging experiments involving an A-70 matrix asphalt and styrene-butadiene-styrene copolymer (SBS)-modified asphalt in the laboratory, over aging times of 0, 40, 85, 180, 240, and 300 min. Second, traditional physical property tests, dynamic shear rheological (DSR) tests, and bending beam rheological (BBR) tests were carried out for asphalt binders with different aging degrees, and the microstructure was analyzed by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Finally, principal component analysis (PCA) was used to evaluate the significance of the aging evaluation indexes of A-70 matrix asphalt and SBS-modified asphalt, the least-squares method (LSM) was used to eliminate the multicollinearity between the independent variables, and a prediction model for asphalt’s short-term aging behavior was developed. The findings suggest that as the degree of aging increases, the penetration, ductility, roughness, and $m-\text{value}$ of asphalt gradually decrease, but other aging evaluation indicators increase. The addition of the SBS modifier will effectively prevent asphalt from oxidizing. Based on the PCA results, the carbonyl index, sulfoxide index, and root-mean square roughness $Rq$ had the most significant relations with the short-term aging behavior of asphalt. In addition, the correlation coefficients between the measured values and predicted values of asphalt macroindexes were more than 0.85, which indicates that the established regression model can accurately predict changes in the physical and rheological properties of asphalt during short-term aging.

Aggregate particle size distributions, shape characteristics, proportions and compaction level collectively influence packing density and, in turn, concrete properties. However, the available packing density prediction models either do not account for aggregate shape characteristics or if they do, the calculations are complicated and applicable only for well-graded aggregate systems. Hence, there is a need for the development of a simple and systematic model to predict aggregate packing density. The Aggregate Image Measurement System (AIMS) was used to obtain the shape parameters of aggregates. Aggregate shape indices were developed to correlate binary (gap-graded) aggregates. A new simple and structured RNP (Ramakanta Nabodyuti Prakash) model is presented in this paper for the estimation of packing density of binary coarse aggregate combinations with the use of shape parameters. The model was developed using a discrete element method (DEM) simulation in EDEM and validated using the experimental results. In the final section of the study, the compressive strength of engineered gap-graded concrete was also evaluated to test the applicability of the model.

The current research on the moisture diffusion behavior in asphalt mostly discusses static water without considering dynamic pore water. In this paper, Fick, Two-stage, and Langmuir moisture diffusion models were used to compare and analyze the diffusion behavior of static water and dynamic pore water in asphalt, and the effects of polar component content on moisture diffusion behavior was quantitatively analyzed. The results show that: (1) dynamic pore water significantly increases the moisture diffusion coefficient of the entire diffusion process; (2) the Langmuir moisture diffusion model, which considers the interaction between moisture and the polar components of asphalt, can very accurately characterize the moisture diffusion behavior in the asphalt binder; and (3) the asphaltene (polar components) content is positively correlated with the amount of asphalt moisture absorption, especially the bound phase moisture.

Cross-laminated timber (CLT) panels have been adopted as main structural elements in the mass timber constructions that have recently caught the attention from different stakeholders. The enhanced mechanical performances allow the design of impressive structures like tall buildings. However, not so much is known about the performance of CLT panels under service life condition. In this context, the strain distribution taken from an experimental campaign carried out using Digital Image Correlation (DIC) is considered as a basis to investigate the stress distribution presented by CLT panels under cyclic moisture variations. Four CLT configurations promoting different moisture flow were conditioned in climatic chambers for 324 days at a constant temperature of 20°C, and with a humidity cycle varying every 21 days between 30% and 90%, getting constant at 65% after the first 142 days. Strains calculated through DIC, along with moduli of elasticity defined by ultrasound tests, were used to estimate strained and released stresses, respectively, before and after cutting specimens. Results show that sealing CLT panels play an insignificant role on distribution of stress induced by cyclic moisture, but peak stresses, both tension and compression resulted from wetting and drying cycles, respectively, were reduced in many specimens, especially when longitudinal faces were sealed. Moreover, as general recommendations to take in the design of CLT panels regarding moisture changes, it is possible to identify the need to limit the longitudinal length of panels, to use more thin layers rather than less thick ones, and to protect panels in the longitudinal direction, owing to high stress concentrated along this direction, particularly in the borders.

This study deals with the trends of fatigue life between asphalt binders and mixtures using the rate of dissipated energy change (RDEC) approach. To this end, the time sweep and four-point beam fatigue tests were utilized to assess the fatigue life of bituminous materials under different strain amplitudes. The results indicated that the RDEC approach can be utilized as asphalt mix fatigue estimation in terms of asphalt binder fatigue life. A separate unique relationship exists between the fatigue life of asphalt materials and their plateau value (PV) covering different types of materials and strain levels. Furthermore, a fatigue model was developed based solely on the PV values of asphalt binders and mixtures including all the materials and the strain levels used in this study. Results revealed conformity between time sweep and four-point beam fatigue tests in terms of RDEC methodology, and a strong correlation exists between these two fatigue tests.

Rotation welding is a novel technique to produce structurally efficient wood joints without any synthetic adhesives, in which wooden dowels are inserted into timber members by high-speed rotation to form the bonding interface layer. This assembly technique is usually used for furniture, but the relatively short inserted dowel length restricts its structural applications due to the lack of molten materials from dowels and the fracture of dowels. Densified wood can be more suitably used as wooden dowel materials, which can provide more molten materials and higher mechanical properties. This study presents the experimental results on densified wood dowels welded in glulam substrate. The effect of the main parameters on the pullout resistance was analyzed, such as the ratio of the diameter of the wooden dowel to the diameter of the predrilled hole in the substrate, the depth of the predrilled hole, the insertion direction, and dowel materials. The welded joints made with densified wood dowels show higher pullout resistance than those with natural wood dowels reported in the literature. The diameter ratio of the dowel to the hole (12/9) can be optimized to yield better pullout resistance, and a longer inserted dowel length can be realized without a fracture of the dowels. The main difference with respect to the insertion direction is the optimum depth of the hole.

To establish a new gene database and asphalt mixture evaluation method, coarse aggregate contact characteristics from the meso perspective serve as a reference for the improvement of fine design and asphalt mixture performance. In this study, a rapid analysis and evaluation software for coarse aggregate contact software was developed. An optimization calculation method for voids in coarse aggregate of asphalt mixture was proposed based on digital image processing techniques. In addition, the meso characteristic gene of coarse aggregate contact for eight different asphalt mixtures was investigated, and the relationship between coarse aggregate contact mesogenetic parameters and the corresponding macrorutting resistance was established. The results indicate that number of contact points is not appropriate as the mesoparameter for evaluating the skeleton of the asphalt mixture; average coordination number, skeleton ratio, and “free” coarse aggregate content can be used to evaluate the mesostructure of the asphalt mixture. Skeleton ratio is the most sensitive mesogenetic parameter affecting rut depth, which can be used as the main control parameter for fine design of asphalt mixture. The limit standards of the skeleton ratio and “free” coarse aggregate content values are 41.32% and 82.89%, respectively, and the range of average coordination numbers is 0.5–1.72. However, the mesodesign parameters cannot reach the standard theoretical value due to the inhomogeneous granular material characteristics of the asphalt mixture. In the asphalt mixture design process, average coordination number is $\ge 1.50$, skeleton ratio is $\ge 23.48\%$, and “free” coarse aggregate content is $\le 24.94\%$; these values can be used as the mesoparameter standard for the fine design of skeleton asphalt mixtures.

The use of copper slag as an alternative to natural fine aggregates in concrete construction has two advantages: effective management of hazardous waste and assistance in conserving natural resources. In order to build confidence among stakeholders and to improve the utilization of copper slag in concrete construction to the required extent, this article evaluates the interfacial transition zone (ITZ) of hardened copper slag concrete composites through various experimental studies. This includes tests on compressive and split-tensile strengths, sorptivity, microhardness, and microcrack properties of ITZ. This paper also examines the surface morphology of ITZ along with its elementary compositions using field emission scanning electron microscopy (FESEM) imaging and energy dispersion spectroscopy (EDS) analysis. The results show that copper slag improves the ITZ characteristics of hardened concrete due to its higher level of pozzolanic reactivity compared to natural sand.

This paper outlines a framework for a potential testing protocol in which specimens are cast following typical industry practices, cured following a specific combination of insulting blocks and variable temperature boundary conditions, and then tested to approximate in-place mechanical properties. Protocols to cure specimens following a time–temperature profile of a high-strength concrete mass placement were developed so that mechanical properties can be measured directly. Findings showed that laboratory equipment was capable of replicating time–temperature profiles of mass concrete structures, and one protocol was recommended for a specific set of conditions. This framework is envisioned to be the foundational component of a standard method in which in-place properties of mass high-strength concrete placements can be predicted by a commercial testing laboratory that already conducts standard concrete tests. Future work is needed to extrapolate the proposed framework for different mixtures, placement sizes, and insulation types; this paper validates that the framework is possible.

This paper presents technical and sustainability analyses evaluating the feasibility of using recycled plastics in the stabilization of kaolinite rich soils. A series of experimental studies were performed to evaluate the stress-strain behavior of soil–cement mixtures reinforced with recycled high-density polyethylene (HDPE) and polypropylene (PP) plastic pellets. Laboratory studies were performed on soil samples containing different percentages of cement, recycled HDPE, and PP pellets to investigate the effectiveness of recycled plastics in enhancing the strength characteristics and ductile behavior of kaolinite soils. The results indicated that soils stabilized with 9% to 15% by weight of cement and reinforced with 4% to 12% by weight of recycled HDPE and PP pellets (sized 3 to 4 mm) met the strength requirements for pavement base and subgrade layers. It was also observed that the plastic-reinforced soils showed a ductile nature with increased failure strain values. Cumulative sustainability index ($I_{\mathrm{sus}}$) was defined and was used to evaluate the environmental impact of using recycled plastics in pavement base and subgrade layers. The treatment mix design with the lowest $I_{\mathrm{sus}}$ value is recommended for future implementation projects. This research highlighted the use of recycled HDPE and PP pellets in enhancing the strength and deformation characteristics of pavement base and subgrade layers.

This study demonstrates the potentials of using Cuttle Bone Powder (CBP) as a biofiller and a low-cost sustainable alternative to cement for the production of lightweight Foamed Mortar (FM). The effects of varying Foam Volume (FV), as well as cuttlebone powder at various particle sizes (fine and coarse) and cement replacement ratio (5%, 10%, 15%, 20%, and 25% by weight) on the physical, mechanical, thermal, and durability properties of foamed mortar, are experimentally investigated. Results show that the inclusion of cuttlebone as cement replacement under moist curing showed decreased density with minimal reduction in strength with increasing foam volume. Besides, to enhance the hydrophobic behavior of the foamed mortar, Zinc Stearate (ZnS) at 1% (by weight of cement) was used in foamed mortar which decreased the water absorption and sorptivity. The thermal conductivity values also slightly decreased with increasing cuttlebone replacement. With the beneficial effect observed on the density and strength performance and from the cost analysis, cuttlebone as cement replacement with ZnS addition is recommended for the production of low-cost sustainable hydrophobic foamed mortar.

Viscoelastic (VE) damper is usually vulcanized by mixing polymer matrix, additives, and fillers, all of which have a great influence on the viscoelastic response of the material. In this study, a series of novel samples of VE materials have been produced by adding different kinds and amounts of organic small molecule modifiers (AO1035, AO60, and AO80) to neat nitrile-butadiene rubber (NBR). The mechanical properties of VE materials have been tested on a dynamic mechanical analyzer and universal testing tensile machine, and the most excellent formulation was selected for manufacturing VE damper. The dynamic mechanical properties of the VE material in the damper with amplitude and frequency are tested and analyzed. The results indicate that the VE damper has a high energy dissipation capacity. To clarify the dynamic mechanical properties of the novel VE material, a high-order fractional derivative model is proposed, which considers the effects of amplitude and frequency simultaneously based on the energy dissipation mechanism of the novel VE material. Finally, the calculated results using this model are compared with the tested data, which has verified the correctness of the mathematical model.

Bimetallic steel bar (BSB) consisting of S30408 stainless steel (cladding layer) and HRB400 carbon steel bar (substrate) has outstanding durability, indicating its suitability for RC structures in corrosive environments. The effects of fire on the mechanical properties of BSB in relation to its metallographic structure (MS) were investigated experimentally by exposing BSB specimens to different elevated temperatures and cooling methods. When the exposure temperature (ET) was lower than the austenite transformation temperature, the changes in the MS were relatively small. When the ET was higher than 700°C, lamellar pearlite and lath martensite were formed in the substrate of BSB specimens with cooling in air (CIA) and cooling in water (CIW), respectively, which led to changes in the mechanical properties. The hardness of the BSB specimens also was affected by the ET and cooling method. There always was a yield plateau in the stress–strain curve of the BSB specimens with CIA. When the ET ranged from 700°C to 900°C, the formation of granular pearlite improved the homogeneity of cementite in ferrite, which enhanced the ductility. For BSB specimens with CIW, when the ETs were 800°C and 900°C, the yield plateau in the stress–strain curve disappeared because of the lath martensite in the substrate. Ductile dimples were observed in the scanning electron microscope images of the BSB specimens with CIA. However, for BSB specimens exposed to 900°C with CIW, the ductile dimples were almost negligible.

Ultraviolet (UV) radiation and thermal oxidation are two leading causes of the aging of asphalt pavements. However, there is a lack of a suitable analytical model to consider both when the field aging gradient of asphalt pavement is analyzed. This work develops a framework of using coupled diffusion-kinetics aging model (CDKAM) to quantify the field aging gradient in asphalt pavements, which considers the influence of both UV and thermal conditions. First, the general diffusion model based on Fick’s second law is proposed to analyze asphalt aging extent and aging gradient due to UV radiation. Then, the kinetics model that could quantify the thermal aging of asphalt is revised and coupled with the diffusion model to develop the CDKAM. Both the diffusion model and CDKAM are validated using the experimental data from the literature. The results exhibit the efficacy of using the diffusion model to analyze the asphalt aging gradient under UV radiation. The CDKAM is demonstrated to be an effective model in assessing the field aging gradient in asphalt pavements. The required inputs for CDKAM are discussed, and future works are recommended to improve the accuracy of using the CDKAM to predict the field aging in asphalt pavements.

This study aims to investigate the properties of novel waterborne epoxy modified asphalt emulsion with styrene–butadiene–chloroprene rubber (SBR/CR) and evaluate its performance improvement mechanism. To achieve this objective, Brookfield rotational viscometer tests and dynamic shear rheometer tests were first performed to characterize the rheological properties of new emulsion residues with time. Then, penetration, softening point, and ductility tests were adopted to evaluate the conventional performance of the new emulsion residue. Finally, the curing microstructures, functional group changes, and thermal stability of new emulsion were analyzed by using scanning electron microscopy, Fourier transform infrared spectrometry, thermal gravimetric analysis, and differential scanning calorimetry, respectively. The experimental results showed that the new emulsion residue showed an extremely high viscosity, and its viscosity value was more than 40 times that of general asphalt emulsion. The stiffness and thermal stability of new emulsion at high temperatures were significantly improved by crosslinking the epoxy system to form a three-dimensional polymer network. The incorporation of SBR/CR copolymer reduced the effect of waterborne epoxy cured products on the low-temperature elongation performance of new emulsion, resulting in improved thermal cracking resistance of the new emulsion system. The optimum dosage of waterborne epoxy for the new asphalt emulsion determined was 15% by weight of SBR/CR modified asphalt emulsion. Based on these results, it is evident that the waterborne epoxy asphalt emulsion together with the SBR/CR copolymer can form a durable emulsion system in both low- and high-temperature environments.