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1 Experimental programme Seven models of reinforced beams are established. And the beam L1 is not reinforced contrast beam. The beam L2 ~ L5 are the beams with unprovoked anchorage reinforcement. L2 and L3 are direct reinforced beams. L4 and L5 are the secondary load reinforced beams, and requires that the two largest deflection beams' span reached 1/300 of a total span when unloaded. The size and reinforcement of beams section are as shown in Fig. 1-2[4]. Fig. 1 Sketch of size and loading point Fig. 2 Sketch of reinforced beams out of end anchorage.
DOI: 10.1002/9781118635360.app2
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2 Reinforcement scheme[5] The diameter of the stainless steel wire mesh which is applied to firm isΦ3. 2. The elastic modulus is 1. 16 × 105 Mpa. The standard tensile strength is 1280Mpa. The steel wire section area which used to strengthen L2~L5 is 35. 6mm2 . The parameters of specimen are as shown in Tab. 1. Tab. 1 Parameters of the specimen Beams No. The steel at the bottom of beams Reinforcing steel strand Clear-span L0/mm Specimen type L1 412 — 3000 Contrast beams L2 412.
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2 3000 Beam I L3 412.
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2 3100 Beam I L4 412.
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2 3100 BeamⅡ L5 412.
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2 3100 BeamⅡ.
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3 Basic assumption[6] (1)The normal section deformation of strand reinforced RC beams should be applied to satisfy the plane section assumption. That is, assuming the total cross section of beams remain plane deformation. That is, pressure zone, tension zone and the strain of concrete, fixture and strand should conform linear change. (2)The tensile strength of concrete can be ignored . Whether it's yield state or limit state, the polymer mortar in tension zone and concrete would split , the force and torque next to neutral axis is so small that can be ignored too. (3)The stress-strain constitutive of concrete and fixture should satisfy《Design of Concrete Structures》and the polymer mortar apply the same constitutive model as that of concrete . (4)The material of reinforced concrete, the interface between polymer mortar and concrete , the interface between high strength wire and polymer mortar are sticked better. the strain among them are coordinate, no slide and not speel off. (5)The influence of surroundings can be ignored when they are conserved, that is , the changing of Stress and strain owing to the Concrete shrinkage and creep can be ignored.
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4 The finite element model[7] The concrete and mortar apply SOLID65 unit , MISO constitutive model using Separate modeling style. That is, Multiple linear constitutive model and William-Warnke five parameters Failure criterion. The Material constants are different, the Poisson's ratio of concrete is 0. 2; fixture and strand apply LINK8 unit and BISO constitutive model, that is, Bilinear constitutive model. SOLID65 unit and LINK8 unit share node, that is, the Poisson's ratio of fixture is 0. 3 when the Bonded slip can be ignored. The Finite element model is as shown in Figure 3~7. Fig. 3 Reinforced FEM model Fig. 4 Concrete FEM model Fig. 5 Polymer mortar FEM model Fig. 6 Strand finite element model Fig. 7 The whole finite element model.
DOI: 10.1201/9781482271225-45
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Test results Tab. 2 The results of normal section flexural load-carrying capacity analysis by ANSYS Beams No. My/ KN·m Increase rate（%） Mu/ KN·m Increase rate（%） L1.
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569 — L2.
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011 Note: My shows calculated value of ANSYS Mid-span torque when the longitudinal reinforcement in tension start yield. Mu shows calculated value of ANSYS mid-span ultimate torque.
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1 The normal section flexural load-carrying capacity of beams Fig. 8 The results of normal section flexural load-carrying capacity analysis by ANSYS Conclusion can be getting in Tab. 2 and Fig. 8: The My and Mu of Reinforced RC beams have a improvement compared to contrast beams, and the increase amplitude decreases with the increase of span; the My and Mu increase amplitude of direct reinforcement beams is large than its of the secondary load's, the yield moment of mid-span increased 8. 532%~15. 096%, the ultimate bending moment increased 9. 780%~19. 659.
DOI: 10.3390/ma12193085
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2 The vertical deflection distribution of beams.
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2. 1 The vertical deflection distribution of beams under limit condition Fig. 9 The distribution of L1 Fig. 10 The distribution of L2 Fig. 11 Distribution of L3 Fig. 12 The distribution of L4 Fig. 13 The distribution of L5 Conclusion can be getting in Fig. 9~13: Beams No. L1 L2 L3 L4 L5 The maximum deflection/mm.
DOI: 10.17816/maj19327-36-18791
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37 116. 049.
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007 The interval value of Each node vertical deflection in the limit condition/mm -63. 551~5. 919 -84. 217~7. 679 -71. 37~6. 172 -116. 049~9. 992 -66. 007~6. 039.
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2. 2 The mid-span deflection when it reach yielding and ultimate bending moment Tab. 3 The mid-span deflection when it reach yielding and ultimate bending moment Beams No. My / KN·m Δy / mm Deflection amplitude Mu / KN·m Δu / mm Deflection amplitude L1.
DOI: 10.2172/4018130
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247 — L2.
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691 -22. 44.
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383 -10. 36% L3.
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845 -29. 21.
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074 -27. 38.
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566 -15. 44.
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16% Note: Δy is the yielding mid-span deflection；Δu is the ultimate bending mid-span deflection；+"said the increase of deflection，"-, said the deflection decreases. Fig. 3 The mid-span deflection when it reach yielding and ultimate bending moment Conclusion can be getting in Tab. 3 and Fig. 8: When yielding： 1) under the same span, the mid-span deflection of reinforced RC beams decreased compare with the comparative beam, and the amplitude of direct reinforced beams is Larger than its of secondary load of reinforced beams, such as the mid-span deflection of L3 which decreases 29. 21%, and L4 decreases 27. 38%; the mid-span deflection of reinforced RC beams increased with yield moment increasing . 2) under the same condition of reinforcement, the mid-span deflection of RC beams is influenced by its span, and it increased by the mid-span commonly; the mid-span deflection increased with yield moment increasing. When ultimate bending: 1) under the same span, the mid-span deflection of reinforced beams increased compare with the comparative beam; such as the mid-span deflection of L3 which increases 2. 34%, and L4 increases 3. 80%; the mid-span deflection of reinforced RC beams increased with yield moment increasing. 2) under the same condition of reinforcement, the mid-span deflection of RC beams is influenced by its span, and it increased by the mid-span decreasing commonly; the mid-span deflection increased with yield moment decreasing. 3)the mid-span deflection of same strengthening state beams in the yielding changes little than when it in the ultimate bending moment , such as L2, the mid-span deflection reduced 22. 44% in the yielding than the comparative beam , while in the ultimate bending moment, it reduced 10. 36.
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Conclusions and recommendations (1)In practical engineering, the beam which exists the defect of design of yield torque and ultimate torque, it can improve yield torque and ultimate torque of beam by using steel wire mesh-polymer mortar, so that it can satisfy the force of structure or component in practice. (2)By using the same reinforcement measures, the effect which reinforcement yield phase reduced beam span deflection is better than that of reinforcement yield phase (3)The initial load has a huge impact on the force of strengthened beam span in order to get the best reinforcement effect, in the actual reinforcement Engineering, the original load of structure should be removed and reinforced (4)The initial load has a huge impact on the mid-span deflection of strengthened beam span. Therefore, in order to get the best reinforcement effect, in the actual reinforcement Engineering, the original load of structure should be removed and reinforced Reference.
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