Experiments were carried out to design polyvinyl alcohol （PVA） fiber reinforced cementitous composites （PVA-FRCCs） holding high ductility and energy consumption ability. Besides, the properties of each ingredients...Experiments were carried out to design polyvinyl alcohol （PVA） fiber reinforced cementitous composites （PVA-FRCCs） holding high ductility and energy consumption ability. Besides, the properties of each ingredients in composites, mixing method and technology for fresh mixture were described in detail. Then, the pseudo-strain-hardening （PSH） behavior was investigated in uniaxial tension test. As a result, the maximum ultimate tensile strain can reach 0.7 percent. On the other hand, the single edge notch （SEN） thin sheet specimens were employed to gain the normal tensile load via crack mouth opening displacement （CMOD） curves, which can show obvious PSH behavior. In addition, the curves can be divided into four zones whose fracture toughness calculation methods were discussed. The wedge splitting （WS） test method can be applied to discuss the fracture toughness. Moreover, fracture energy of SEN and WS specimens were both approximately evaluated.展开更多
In order to improve the spinnabilities of A95 alumi- na silica sols, the influences of addition and polymeriza- tion degree of polyvinyl alcohol on spinnabilities of alu- mina silica sols were researched. The viscosit...In order to improve the spinnabilities of A95 alumi- na silica sols, the influences of addition and polymeriza- tion degree of polyvinyl alcohol on spinnabilities of alu- mina silica sols were researched. The viscosity and rheo- logical properties of the sols, mierostructure, infrared spectra, average diameter and diameter distribution oJ the gel fibers, BET specific surface area and distribution of pore diameters were measured. The results show that iJ there is no spinning agent, the A95 sols have no spinna- bility ; when PVA 2099 addition is in the range of l. 0% -2.0% （in mass, the same hereinafter） , the prepared sols have good spinnability, the gel fibers produced are thin and uniform, and the shot content is low ; BET spe- cific surface area and gas absorption amount of A95 polycrystalline alumina fibers are the largest when PVA 2099 addition is 2. 0% ; the gel fibers are thick and non-uniform, and the shot content is high when PVA 2099 addition is 4. 0% ; with polymerization degree oJ PVA increasing, the average diameter and diameter dis- tribution range of the gel fibers increase gradually; when using PVA 1799 and PVA 1899, respectively, the spun gel fibers are thin and uniform.展开更多
Vigorous and continued efforts by researchers and engineers have contributed towards maintaining environmental sustainability through the utilization of waste materials in civil engineering applications as an alternat...Vigorous and continued efforts by researchers and engineers have contributed towards maintaining environmental sustainability through the utilization of waste materials in civil engineering applications as an alternative to natural sources.In this study,granite aggregates in asphaltic mixes were replaced by electric arc furnace(EAF)steel slag aggregates with different proportions to identify the best combination in terms of superior performance.Asphalt mixtures showing the best performance were further reinforced with polyvinyl alcohol(PVA),acrylic,and polyester fibers at the dosages of 0.05%,0.15%,and 0.3%by weight of the aggregates.The performance tests of this study were resilient modulus,moisture susceptibility,and indirect tensile fatigue cracking test.The findings of this study revealed that the asphalt mixtures containing coarse steel slag aggregate exhibited the best performance in comparison with the other substitutions.Moreover,the reinforced asphalt mixtures with synthetic fibers at the content of 0.05%exhibited an almost comparable performance to the unreinforced asphalt mixtures.Modifying the asphalt mixtures with PVA,acrylic,and polyester fibers at the proportion of 0.15%have improved the fatigue cracking resistance by 41.13%,29.87%,and 18.97%,respectively.Also,the fiber-modified asphalt mixtures with PVA,acrylic,and polyester have enhanced the fatigue cracking resistance by about 57%,44%,and 39%,respectively.The results of the resilient modulus demonstrated that as the fiber content increase,the resilient modulus of the reinforced asphalt mixtures decreases.Therefore,introducing synthetic fibers at the content of 0.3%has slightly decreased the resilient modulus in comparison with unreinforced mixtures.On the other hand,the results of the mechanisticempirical pavement design showed that the reinforced asphalt mixes with a high content of synthetic fibers have shown lower service life than the control mixes due to the low resilient modulus.On the contrary,based on the laboratory results,the asphalt mixes incorporating PVA,acrylic,and polyester fibers at the proportion of 0.15%have shown the potential to reduce the thickness of the asphalt layer by about 14.9%,11.80%,and 8.70%,respectively.展开更多
基金Committee on Science and Technology Foundation of China(No.50438010)The Research of Formation Progress and Control Technology of Concrete Structure Cracks
文摘Experiments were carried out to design polyvinyl alcohol （PVA） fiber reinforced cementitous composites （PVA-FRCCs） holding high ductility and energy consumption ability. Besides, the properties of each ingredients in composites, mixing method and technology for fresh mixture were described in detail. Then, the pseudo-strain-hardening （PSH） behavior was investigated in uniaxial tension test. As a result, the maximum ultimate tensile strain can reach 0.7 percent. On the other hand, the single edge notch （SEN） thin sheet specimens were employed to gain the normal tensile load via crack mouth opening displacement （CMOD） curves, which can show obvious PSH behavior. In addition, the curves can be divided into four zones whose fracture toughness calculation methods were discussed. The wedge splitting （WS） test method can be applied to discuss the fracture toughness. Moreover, fracture energy of SEN and WS specimens were both approximately evaluated.
文摘In order to improve the spinnabilities of A95 alumi- na silica sols, the influences of addition and polymeriza- tion degree of polyvinyl alcohol on spinnabilities of alu- mina silica sols were researched. The viscosity and rheo- logical properties of the sols, mierostructure, infrared spectra, average diameter and diameter distribution oJ the gel fibers, BET specific surface area and distribution of pore diameters were measured. The results show that iJ there is no spinning agent, the A95 sols have no spinna- bility ; when PVA 2099 addition is in the range of l. 0% -2.0% （in mass, the same hereinafter） , the prepared sols have good spinnability, the gel fibers produced are thin and uniform, and the shot content is low ; BET spe- cific surface area and gas absorption amount of A95 polycrystalline alumina fibers are the largest when PVA 2099 addition is 2. 0% ; the gel fibers are thick and non-uniform, and the shot content is high when PVA 2099 addition is 4. 0% ; with polymerization degree oJ PVA increasing, the average diameter and diameter dis- tribution range of the gel fibers increase gradually; when using PVA 1799 and PVA 1899, respectively, the spun gel fibers are thin and uniform.
基金This work was supported by Universiti Tenaga Nasional(UNITEN)through BOLD Refresh Publication Fund 2021 under Grant J5100D4103-BOLDREFRESH2025-CENTRE OF EXCELLENCE.
文摘Vigorous and continued efforts by researchers and engineers have contributed towards maintaining environmental sustainability through the utilization of waste materials in civil engineering applications as an alternative to natural sources.In this study,granite aggregates in asphaltic mixes were replaced by electric arc furnace(EAF)steel slag aggregates with different proportions to identify the best combination in terms of superior performance.Asphalt mixtures showing the best performance were further reinforced with polyvinyl alcohol(PVA),acrylic,and polyester fibers at the dosages of 0.05%,0.15%,and 0.3%by weight of the aggregates.The performance tests of this study were resilient modulus,moisture susceptibility,and indirect tensile fatigue cracking test.The findings of this study revealed that the asphalt mixtures containing coarse steel slag aggregate exhibited the best performance in comparison with the other substitutions.Moreover,the reinforced asphalt mixtures with synthetic fibers at the content of 0.05%exhibited an almost comparable performance to the unreinforced asphalt mixtures.Modifying the asphalt mixtures with PVA,acrylic,and polyester fibers at the proportion of 0.15%have improved the fatigue cracking resistance by 41.13%,29.87%,and 18.97%,respectively.Also,the fiber-modified asphalt mixtures with PVA,acrylic,and polyester have enhanced the fatigue cracking resistance by about 57%,44%,and 39%,respectively.The results of the resilient modulus demonstrated that as the fiber content increase,the resilient modulus of the reinforced asphalt mixtures decreases.Therefore,introducing synthetic fibers at the content of 0.3%has slightly decreased the resilient modulus in comparison with unreinforced mixtures.On the other hand,the results of the mechanisticempirical pavement design showed that the reinforced asphalt mixes with a high content of synthetic fibers have shown lower service life than the control mixes due to the low resilient modulus.On the contrary,based on the laboratory results,the asphalt mixes incorporating PVA,acrylic,and polyester fibers at the proportion of 0.15%have shown the potential to reduce the thickness of the asphalt layer by about 14.9%,11.80%,and 8.70%,respectively.
