Article
Materials Science, Composites
Yuxiang Zhang, Chengwei Wu, Wei Zhang, Xue Zeng, Xiao Han
Summary: This study investigates the curing kinetics and tensile properties of magnetocured epoxy adhesive doped with magnetic nanoparticles (MNPs). It is found that the tensile modulus and strength are strongly influenced by the curing degree (CD) and mass fraction of MNPs. The curing reaction process is described using an isoconversional model. The tensile modulus of the adhesive with 15%wt and 30%wt MNPs increases significantly compared to that with 10%wt MNPs when the curing degree is 0.7, but the increase is not obvious at higher curing degrees. The same trend is observed for the tensile strength, with the samples containing 15%wt and 30%wt MNPs showing much higher strength than the one with 10%wt MNPs under 0.7 curing degree. However, the tensile strength decreases with a higher curing degree. Scanning electron microscopy observation reveals different fracture mechanisms depending on the curing degree. Failure occurs in the adhesive region when the curing degree is below 0.9, while failure initiates and propagates at the interface between adhesive and MNPs when the curing degree is above 0.9. Thus, the intrinsic property of the adhesive plays a role in determining tensile properties at lower curing degrees, while the weak interfacial interaction between adhesive and MNPs has a reverse effect at higher curing degrees.
POLYMER COMPOSITES
(2023)
Article
Chemistry, Multidisciplinary
Lidia Orduna, Itziar Otaegi, Nora Aranburu, Gonzalo Guerrica-Echevarria
Summary: Good dispersion and effective curing were achieved in epoxy/CNT nanocomposites using three different ionic liquids (ILs). IL-based epoxy systems showed lower electrical percolation thresholds compared to conventional amine-cured systems. The addition of CNTs improved the adhesive properties of the nanocomposites, while not significantly affecting their thermal or low-strain mechanical properties. ILs can be used as a sustainable alternative to amine-based curing agents for the production of electrically conductive epoxy/CNT nanocomposites and adhesives.
Article
Engineering, Chemical
Xiaodong Wang, Xin Zhang, Xiaotian Bian, Chenchen Lu, Qi Li, Chengying Bai, Lili Zhang, Ting Zheng
Summary: An SiO2/epoxy adhesive that can cure in a wet/water environment was prepared in this study. The curing reaction of the adhesive was evaluated using nonisothermal differential scanning calorimetry. The isoconversional methods were used to obtain the kinetic parameters of the adhesive. The results showed that the SiO2/epoxy adhesive had increased tensile and flexural strength and modulus compared to pure epoxy resin.
JOURNAL OF ADHESION
(2023)
Article
Materials Science, Multidisciplinary
Hui Wang, Zhaoyi Liu, Yizhe Chen, Lin Hua, Yi Qiu
Summary: This study found that ultrasonic vibration can accelerate the curing rate of epoxy resin adhesive and increase tensile strength, while maintaining temperature stability. Additionally, temperature variations have a significant impact on the properties of the adhesive, with medium-temperature curing being the most suitable option.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Polymer Science
Tianyu Zhu, Chunxiang Lu, Xiaoxuan Lu, Jieying Zhi, Yingjun Song
Summary: A new epoxy-terminated hyperbranched polyether sulfone (EHPES) was synthesized and modified in diglycidyl ether of bisphenol-A (DGEBA), improving the comprehensive performance of the copolymer, especially the tensile, flexural, and impact strengths.
Article
Materials Science, Composites
Zhigang Yuan, Zhicheng Wang, Zhiyi Guo, Yanhui Wang, Jun Wang, Wen-bin Liu, Mehdi Derradji, Jian Qiu
Summary: A novel curing agent was mixed with diatomite particles into epoxy resin to obtain bio-composites that can be rapidly molded and cured at room temperature. The mechanical and thermal properties of the composites were studied, showing that thermal stability increased with higher CP fillers content. Additionally, dielectric property tests confirmed a decrease in dielectric constant due to the incorporating of novel curing agent and CP fillers with porous structure into epoxy resin.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Zhaoyi Liu, Hui Wang, Yizhe Chen, Guodong Kang, Lin Hua, Jindong Feng
Summary: Ultrasonic curing is an effective method for enhancing the bonding extent of composite materials in the aerospace industry. This study established a variable activation energy model to investigate the mechanism of ultrasonic curing and demonstrated the improved efficiency achieved through the non-thermal effect of ultrasonic.
Article
Materials Science, Multidisciplinary
Ahmed Al-Qatatsheh, Jitraporn Vongsvivut, Saulius Juodkazis, Nisa V. Salim, Nishar Hameed
Summary: The use of a coordinated silver (I) complex based on solvate ionic liquid in epoxy resins enables unprecedented electrical and thermomechanical properties. The aligned molecular structure achieved through electric field treatment results in high electrical conductivity, excellent energy storage properties, and rapid curing behavior. Quantum mechanics and synchrotron beamline techniques are utilized to optimize and investigate the properties of the system, paving the way for the next generation of thermoset polymers with multifunctional properties.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Construction & Building Technology
Qiusheng He, Henglong Zhang, Jia Li, Haihui Duan
Summary: This study investigated the curing process and mechanical properties of PEA, finding that PEA has better high-temperature stability and excellent mechanical properties compared to SBS modified asphalt.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Polymer Science
Jiachen Wang, Wei Liu, Huan Liu, Xiaodong Wang, Dezhen Wu, Shuangkun Zhang, Shaowei Shi, Weiwei Liu, Zhanpeng Wu
Summary: A novel epoxy monomer, CP-EP, composed of nontoxic eugenol and nonflammable cyclotriphosphazene, was successfully synthesized in this work. The resulting cyclotriphosphazene-based thermosets (CPTs) exhibited improved properties compared to bisphenol-A epoxy resin, including higher glass transition temperature, enhanced mechanical strengths, and enhanced nonflammability. The use of this environmentally friendly and fire-safe epoxy thermosetting system has the potential to benefit both the environment and human health.
Article
Agricultural Engineering
Maoping Lyu, Xiangyu Yang, Jing Li, Fei Xie, Hebo Shi, Xinhu Gong, Xusheng Huang, Dandi Fang, Chaoqun Zhang
Summary: Developing novel multifunctional polymeric materials from biomass to replace traditional electric encapsulation materials is significant for energy consumption and sustainable development. This study prepared bio-based epoxy thermosets from different epoxidized plant oils and investigated their properties and structure. Among them, soybean oil-based thermoset showed superior performance and was identified as a suitable candidate for encapsulation materials.
INDUSTRIAL CROPS AND PRODUCTS
(2024)
Article
Materials Science, Composites
Lorena Saitta, Vishnu Prasad, Claudio Tosto, Neal Murphy, Alojz Ivankovic, Gianluca Cicala, Gennaro Scarselli
Summary: The study focuses on composite fabrication, characterization, and recyclability of biobased polymer resins reinforced with flax fiber. By selecting different biobased resins and evaluating their mechanical properties, an epoxy resin cured with a cleavable hardener is found to have the highest glass transition temperature, ensuring full recyclability. The study also demonstrates the possibility of separating and recovering fibers and resin from composite panels through a specific chemical process.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Jiaming Liu, Xiaohong Liu, Xiaohua Cui, Jingjing Qin, Mengqin Wu, Lifu Fu, Min Shi, Dingsong Wang, Liyan Liang
Summary: Using biomass resources to prepare thermosets is a growing trend in sustainable society, and resveratrol-derived epoxy thermosets with active ester hardeners show promise in the electronic packaging field. The study synthesized resveratrol-derived epoxy and two active ester hardeners, and prepared bio-based epoxy thermosets. It was found that the REP/TAR thermosets exhibited better properties than REP/TTR thermosets in terms of gel fraction, solvent resistance, glass transition temperature, and thermal stability.
Article
Chemistry, Applied
Mingyu Ou, Richeng Lian, Jianhao Zhu, Rongjia Li, Jiahui Cui, Haocun Guan, Lei Liu, Chuanmei Jiao, Xilei Chen
Summary: A novel aromatic phosphorus/nitrogen/cobalt-containing microsphere flame retardant (FNP-Co) was synthesized and used to fabricate high-performance epoxy resin (EP) coatings. EP coatings containing FNP-Co exhibited remarkable fire safety performance, enhanced mechanical properties, and lower curing temperature. The FNP-Co promoted the formation of a honeycomb-like and compact char layer during combustion, providing a labyrinth effect and barrier effect to inhibit heat and pyrolysis gas transfer.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Materials Science, Textiles
Surajit Sengupta, Papai Ghosh, Izhar Mustafa
Summary: The study focused on the effect of different process parameters on the mechanical properties of poly-vinyl alcohol bonded nonwoven fabric. Second-order polynomials were proposed with a good correlation for all properties, providing a means to predict properties based on parameter values. The information obtained from the models and contour diagrams is useful for designing a fabric with optimum mechanical properties.
JOURNAL OF THE TEXTILE INSTITUTE
(2022)
Article
Polymer Science
Alba Codina, Cristina Barris, Younes Jahani, Marta Baena, Lluis Torres
Summary: This study compares different formulations in predicting intermediate crack debonding (ICD) loads in RC beams strengthened with FRP. The results show that all models can predict the ICD failure mode accurately.
Article
Engineering, Civil
Cristina Barris, Marta Baena, Younes Jahani, Alba Codina, Lluis Torres
Summary: A near-surface-mounted (NSM) technique using fiber-reinforced polymer (FRP) reinforcement is effective in increasing load-bearing capacity and stiffness of reinforced-concrete (RC) beams. However, there is a lack of provisions for crack width prediction due to scarceness of experimental data. This study presents experimental results on the effect of different NSM reinforcement arrangements on midspan deflection, crack spacing, and crack width of NSM FRP RC beams.
JOURNAL OF COMPOSITES FOR CONSTRUCTION
(2023)
Article
Polymer Science
Marta Baena, Younes Jahani, Lluis Torres, Cristina Barris, Ricardo Perera
Summary: This paper evaluates the influence of high service temperatures on the flexural performance and end debonding phenomenon in NSM CFRP-strengthened RC beams. The experimental program includes different parameters and compares predictions with experimental results using an analytical procedure. The results show that as the testing temperature increases, the strengthened beams experience a decrease in capacity and a change in failure mode from FRP rupture to end debonding and concrete crushing.
Article
Construction & Building Technology
Amr El-Nemr, Ehab A. Ahmed, Cristina Barris, Panuwat Joyklad, Qudeer Hussain, Brahim Benmokrane
Summary: This study investigates the bond performance of different types of new generation FRP (fiber-reinforced polymer) bars embedded in concrete. A total of 87 pullout specimens were constructed and tested, and the results show that the bond strength of FRP bars generally decreases with increasing bar diameter, while the bar diameter has insignificant impact on steel bars. There is a positive relationship between the concrete compressive strength and the bond strength gained. The test results are also used to assess different analytical models for bond stress-slip relationships.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Analytical
Ricardo Perera, Maria Consuelo Huerta, Marta Baena, Cristina Barris
Summary: Fiber-reinforced polymer (FRP) strengthening systems have become increasingly popular for retrofitting concrete structures. The two most widely recognized methods, externally bonded reinforcement (EBR) and near-surface mounted (NSM) techniques, may suffer from sudden debonding of the FRP. This study monitored cracks in two reinforced concrete (RC) specimens strengthened with FRP using a piezoelectric-transducer-based electromechanical impedance (EMI) technique and a digital image correlation (DIC) system. The results showed that the combined implementation of these techniques improved the prediction of early cracks and potential failure of the specimens.
Article
Construction & Building Technology
Qi Jiang, Wei Liu, Shaopeng Wu, Xuanwen Gou
Summary: This study analyzes the erosion mechanisms of NaCl solution on asphalt concrete and finds that NaCl solution softens asphalt and promotes the intrusion of crystalline salt into it. Salt crystallization alters the surface roughness of aggregates, resulting in a decrease in skid resistance but an improvement in compressive strength. Additionally, the concentration of NaCl solution initially has no significant impact on the mechanical performance of asphalt concrete, but its domination gradually increases with the intensification of cyclic effects.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Lili Kan, Lan-qing Dai, Ning Kong, Bin Peng, Fei Wang
Summary: This paper investigates the effect of freezing and thawing cycles on the tensile behavior of cracked ultra-high performance concrete (UHPC). The results show that long-term freezing and thawing action deteriorates the cracking strength, tensile strength, tensile strain, and strain energy of cracked UHPC. On the other hand, the action of water generally favors the development of tensile properties of UHPC. The crack distribution tends to be unsaturated under freezing and thawing environment, and the re-hydration reaction is hindered. The pore structure near the crack varies under different environments.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Xin Xiao, Jingwei Li, Qingke Meng, Xiangshan Hou, Yanhui Liu, Xujiang Wang, Wenlong Wang, Shengtao Lu, Yuzhong Li, Yanpeng Mao, Tong Li
Summary: Preparing gypsum-based self-leveling mortar (GSLM) using beta-hemihydrate gypsum and solid wastes-derived sulfoaluminate cement (WSAC) can improve the mechanical performance of the mortar, but phosphorus impurities can weaken the hydration speed and degree.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Sihang Bao, Junzhen Di, Yanrong Dong, Ziqing Gao, Qing Gu, Yuanfang Zhao, Hongyu Zhai
Summary: Tailings dam break and leakage accidents pose a threat to the safety of people in mining areas and cause severe environmental pollution. This study focuses on solidifying tailing sand using microbial induced calcite precipitation (MICP) to improve strength and fix heavy metals. The curing time of MICP bio-cemented tailings is found to significantly impact the strength of tailings, while its effect on heavy metal fixation is minimal. The optimized MICP curing time is 10 days, resulting in improved strength and cementation of tailings particles.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Ferhat Benmahiddine, Fares Bennai, Achraf Charaka, Ameur El Amine Hamami, Abdelkader Tahakourt, Rafik Belarbi
Summary: This paper studied the effects of hysteresis on the hygrothermal behavior at the building scale. Through laboratory validation and numerical simulations, it was found that hysteresis has a significant impact on the relative humidity and total heat fluxes in buildings, while it does not have a noticeable effect on temperature variations.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
You Gao, Wei He, Xiayang Zhang, De'an Sun, Pei Li
Summary: This study determined the boundary line between the swelling and compression deformation zone in lateritic clay through wetting tests, and proposed a simple bimodal SWRC model. It also found that the existing strength model underestimated the tested values in the medium to high suction range, therefore a segmented strength equation was introduced for enhanced predictions of the strength properties of lateritic clay.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Prabhath Ranjan Kumar Soda, Asheer Mogal, Kalyan Chakravarthy, Nikhil Thota, Nimish Bandaru, Sanjay Kumar Shukla, K. M. Mini
Summary: This study investigates the use of encapsulated bacteria to improve the self-healing ability of concrete. Through various tests, it is found that using 20% cement-coated alginate beads (CCAB) and 5% nanosilica (NS) can achieve optimal strength and healing. This research is significant for enhancing the durability of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Shizhe Wang, Haiping Wu, Wen Yang, Wei Wang, Zhibo Zhu, Kun Nie, Luoxin Wang, Hua Wang, Jing Wu
Summary: In this study, photothermal-heat storage concrete (PHSC) was developed with excellent photothermal conversion performance and heat storage capacity. By absorbing and storing solar energy during the day and releasing it at night, PHSC can effectively reduce energy consumption in buildings.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Robin Deb, Jialuo He, Geetika Mishra, Yaghoob (Amir) Farnam
Summary: Incorporation techniques of phase change materials in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates. The results showed that ramp rates affect the nucleation and crystallization growth process during the phase transition, and the pore structure of the aggregates affects the supercooling phenomenon and confinement pressure of the PCM.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Eduardo Ferreira, Payam Sotoudeh, Dagmar Svecova
Summary: This study investigates the fatigue behavior of concrete under different stress reversal conditions. The results indicate that stress reversal generally causes more severe damage and reduces the cycles to failure compared to tensile fatigue. Additionally, adding some level of compression contributes to the energy required for failure under stress reversal fatigue. Specimens with higher concentration of fractured aggregates achieve longer fatigue lives.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Mag Raj Gehlot, Sandeep Shrivastava
Summary: This study evaluates the compatibility relationship between plaster bonds and the substrate under an accelerated aging environment, and finds that incorporating an appropriate amount of granite cutting waste can improve the strength parameters and adhesion of the cement mortar.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Min Zhang, Qirui Luo, Mingke Deng, Shixing Zhao
Summary: This study investigated the bond behavior between carbon FRCM composites with added short fibers and concrete substrates. The effects of different factors were considered and 36 specimens were tested and discussed. The experimental results were analyzed in terms of failure mode, load-slip curve, and characteristic parameters, and the contribution of weft yarns was taken into account in the developed bondslip model.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Dengkai Liu, Hongniao Chen, Ray Kai Leung Su
Summary: The susceptibility of building stones to fire and high temperature was investigated in this study by examining their physical and mechanical properties. The results show that both compressive and tensile properties of stones are affected by temperature changes. The tensile strength is particularly sensitive to temperature changes, requiring special attention to the components subjected to tensile stress in stone buildings. Principal component analysis was used to predict the mechanical properties of stones, providing a new method for calculating the residual mechanical properties after high temperature or fire.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Joso Maria Raposo, Eduardo Cavaco, Luis Costa Neves, Eduardo Julio
Summary: This paper investigates the correlation between the friction coefficient and the surface roughness of concrete-to-concrete interfaces. Experimental tests were performed on specimens with different surface treatments, and the surface roughness parameters were analyzed and correlated with the shear strength and friction coefficient. The results showed that certain roughness parameters had a strong positive correlation with the friction coefficient, while others had little or no correlation. A novel combined roughness parameter with optimized correlation was proposed.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Chiara Riccardi, Massimo Losa
Summary: The interest in using bio materials in asphalt pavements is growing due to economic reasons and environmental benefits. This study aimed to review the use of bio extenders as additives in binders, with a focus on replacements greater than 20% of fossil binder. The properties of bio-extended binders were found to vary substantially depending on the biomass source and production process.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
