Construction scheme of pretensioned prestressed concrete hollow slab beam

In this drawing, the standard spans are 10m, 13m, 16m and 20m. General drawing of pretensioned prestressed concrete hollow slab. I. Description of superstructure of prestressed concrete hollow slab (L=10, 13, 16, 20m, a=0~45 °) Quantity table of main materials for L=10m hollow slab and one hole superstructure, cross-section drawing of superstructure, general structural drawing of precast slab, layout drawing of middle slab reinforcement, quantity table of middle slab materials, layout drawing of side slab reinforcement, quantity table of side slab materials, layout drawing of cast-in-situ layer reinforcement of bridge deck, layout drawing of obtuse angle reinforcement of inclined slab deck, structural drawing of embedded steel plate of support Quantity table of main materials for one hole superstructure of L=13m hollow slab, cross-section drawing of superstructure, general structural drawing of precast slab, layout drawing of middle slab reinforcement, quantity table of middle slab materials, layout drawing of side slab reinforcement, quantity table of side slab materials, layout drawing of cast-in-situ layer reinforcement of bridge deck, layout drawing of obtuse angle reinforcement of inclined slab deck, structural drawing of embedded steel plate of support Quantity table of main materials for upper structure of one hole of L=16m hollow slab, cross-section drawing of upper structure, general structural drawing of precast slab, layout drawing of reinforcement for medium slab, quantity table of material for medium slab, layout drawing of reinforcement for side slab, quantity table of material for side slab, layout drawing of reinforcement for cast-in-situ layer of bridge deck, layout drawing of reinforcement for obtuse angle slab of inclined slab, structural drawing of embedded steel plate of support Quantity table of main materials for one hole superstructure of L=20m hollow slab, cross-section drawing of superstructure, general structural drawing of precast slab, layout drawing of middle slab reinforcement, quantity table of middle slab materials, layout drawing of side slab reinforcement, quantity table of slab materials, layout drawing of cast-in-situ layer reinforcement of bridge deck, layout drawing of obtuse angle reinforcement of inclined slab deck, structural drawing of embedded steel plate of support II Description of substructure drawing of prestressed concrete hollow slab (pier L=10, 13, 16, 20m, a=0 °～ 45 °), general structural drawing of pile column pier (a=0 °～ 45 °), structural drawing of pier cap reinforcement (L=10m; a=0 °～ 45 °), quantity table of pier cap materials (L=10m; a=0 °～ 45 °), structural drawing of pier cap reinforcement (L=13m; a=0 °～ 45 °); A=0 °～ 45 °) Pier Cap Material Quantity Table (L=13m; a=0 °～ 45 °) Pier Cap Reinforcement Structural Drawing (L=16m; a=0 °～ 45 °) Pier Cap Material Quantity Table (L=16m; a=0 °～ 45 °) Pier Cap Reinforcement Structural Drawing (L=20m; a=0 °～ 45 °) Pier Cap Material Quantity Table (L=20m; a=0 °～ 45 °); A=0 °～ 45 °) Structural drawing of pier anchor bolt III Structural drawing of lower part of prestressed concrete hollow slab (abutment L=10, 13, 16, 20m, a=0 °～ 45 °) Description General structural drawing of pile column abutment (a=0 °～ 45 °) Structural drawing of abutment cap reinforcement (L=10m; a=0 °～ 45 °)

1、 Design description 1. 10m prestressed hollow slab adopts pretensioned prestressed concrete structure, and precast slab and hinge joint adopt C50 concrete; C50 concrete is used as the integral cast-in-place concrete, and the prestressed steel strand is Class II low relaxation steel strand in the GB/T 5224-2003 standard, f/pk=1860MPa, and the diameter is φ s/12.7. 2. The stress of main beam under operation is calculated according to the joint force of precast slab, hinge joint and integrated cast-in-place concrete. 3. The effective length of prestressed reinforcement in the drawing has included the force transfer anchorage length of prestressed reinforcement. 4. Prefabricated hollow slab is perforated with inflatable rubber core mold. 5. The inverted arch value at the middle of the span of 10m prestressed concrete slab is 13mm based on 60 days of beam storage. 2、 Key points of construction 1. Because of the high strength of the steel strand, its force transmission anchorage length is considered to be 100d. In case of wire slip, necessary measures must be taken, such as mechanical anchorage with clamps. Effective measures must be taken to deal with the failure of the part beyond the effective length of prestressed reinforcement (imaginary line in the figure). Generally, hard plastic pipes are used to cover the prestressed reinforcement within the failure range, so that the prestressed reinforcement does not have the binding effect with the concrete. 2. The effective length of prestressed reinforcement is symmetrically arranged with the center line of the slab span, so that the failure length at both ends of the slab is equal. 3. The prestressed reinforcement is tensioned with tension and elongation value. The tension control stress is σ/con ＝ 0.75f/pk ＝ 1395MPa, and the tension is 132.17KN. The elongation value is calculated separately according to the tension length of the steel strand during construction. 4. When multiple prestressed tendons are tensioned at the same time, reliable measures shall be taken to ensure that the stress of each tendon is the same. 5. In order to standardize and normalize the tensioning anchor plate, the spacing of prestressed reinforcement is a multiple of 5cm. The blank space of tendon number in the drawing indicates that there is no prestressed reinforcement. 6. The rebar binding shall be carried out 8 hours after the end of tensioning to ensure safety. 7. The relaxation of prestressed steel strand shall be completed symmetrically, evenly and in batches, without sudden relaxation. The actual cubic strength of concrete during relaxation shall not be less than 85% of the design grade. 8. When vibrating the concrete, if the cross frequency immersion vibrator is used, it must be vibrated from both sides at the same time to prevent the inflatable rubber core mold from moving left and right, and to prevent the end of the vibrator from contacting the core mold, resulting in perforation and air leakage. 9. The concrete on the top of precast slab shall be roughened according to the construction specifications. Before pouring the upper layer of concrete, water shall be used to clean it without water, so as to facilitate the combination of cast-in-place concrete with it. 10. The beam storage time of prestressed concrete precast slab shall not be more than 60 days, otherwise excessive camber may occur. 11. When transporting prestressed concrete precast slabs, reliable measures shall be taken to prevent the negative bending moment produced by prestress from damaging. A total of 10 CAD drawings, designed in 2013

Detail drawing of node structure of 16m pretensioned prestressed concrete hollow bridge slab 4 sheets