This research focused on using the waste rubber powder as a kind of regenerate resources to improve the mechanical properties of cement mortar.The two kinds of hybrid modified rubber powder TRP and ATRP were prepared ...This research focused on using the waste rubber powder as a kind of regenerate resources to improve the mechanical properties of cement mortar.The two kinds of hybrid modified rubber powder TRP and ATRP were prepared by sol-gel method and then used in cement mortar.The structures and properties of them were studied.It is shown that the nano Si-O-Si network is generated in TRP and ATRP networks and the hydrophilic group is grafted on the surface of ATRP.The mechanical properties of rubber-treated mortar（RTM） were tested and the microstructures of them were also studied.Compared to the mortars with unmodified rubber powders（RP）,NaOH treated rubber powder（SRP） and coupling agent treated rubber powder（CRP）,the RTM with ATRP has the highest compressive strength and flexural strength.The stress-strain curves shown that the peak of stress of RTM with ATRP is increased and indicated the higher compression deformation and toughness.It is found that the interfacial adhesion between the ATRP and cement mortar is increased distinctly by SEM,which results in enhanced ductility and mechanical properties of RTM with ATRP.展开更多
Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the ...Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the mortar layer and the track slab. Based on the theory of viscoelasticity and the analytical method of the time hardening law(THL), the viscoelastic deformation behavior of CA mortar was studied. Using ABAQUS, we established a solid model of China railway track system(CRTS) Ⅰ prefabricated slab track, with CA mortar at different initial Young’s moduli under cyclic loading corresponding to the influence of actual train loads. The results reveal that the fitted parameters of the THL for CA mortar are suitable for describing its viscoelastic deformation. As the initial Young’s modulus increases, the strain difference before and after cyclic loading gradually decreases, and the displacement difference increases from 0.2 mm to 0.6 mm. The deformation mainly occurs at the end of a mortar layer with longitudinal distribution of about 2.5 times the fasteners’ spacing. It follows that the viscoelastic performance of CA mortar is one of the most important reasons that cause debonding underneath the track slab. Therefore, we suggest that the adverse effects of viscoelastic behavior of CA mortar should be considered when researching such deformation and damage.展开更多
文摘This research focused on using the waste rubber powder as a kind of regenerate resources to improve the mechanical properties of cement mortar.The two kinds of hybrid modified rubber powder TRP and ATRP were prepared by sol-gel method and then used in cement mortar.The structures and properties of them were studied.It is shown that the nano Si-O-Si network is generated in TRP and ATRP networks and the hydrophilic group is grafted on the surface of ATRP.The mechanical properties of rubber-treated mortar（RTM） were tested and the microstructures of them were also studied.Compared to the mortars with unmodified rubber powders（RP）,NaOH treated rubber powder（SRP） and coupling agent treated rubber powder（CRP）,the RTM with ATRP has the highest compressive strength and flexural strength.The stress-strain curves shown that the peak of stress of RTM with ATRP is increased and indicated the higher compression deformation and toughness.It is found that the interfacial adhesion between the ATRP and cement mortar is increased distinctly by SEM,which results in enhanced ductility and mechanical properties of RTM with ATRP.
基金Project supported by the National Natural Science Foundation of China(No.51578472)。
文摘Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the mortar layer and the track slab. Based on the theory of viscoelasticity and the analytical method of the time hardening law(THL), the viscoelastic deformation behavior of CA mortar was studied. Using ABAQUS, we established a solid model of China railway track system(CRTS) Ⅰ prefabricated slab track, with CA mortar at different initial Young’s moduli under cyclic loading corresponding to the influence of actual train loads. The results reveal that the fitted parameters of the THL for CA mortar are suitable for describing its viscoelastic deformation. As the initial Young’s modulus increases, the strain difference before and after cyclic loading gradually decreases, and the displacement difference increases from 0.2 mm to 0.6 mm. The deformation mainly occurs at the end of a mortar layer with longitudinal distribution of about 2.5 times the fasteners’ spacing. It follows that the viscoelastic performance of CA mortar is one of the most important reasons that cause debonding underneath the track slab. Therefore, we suggest that the adverse effects of viscoelastic behavior of CA mortar should be considered when researching such deformation and damage.
