【Daily Discussion】Utilities - Civil Engineering - 20210506

A construction joint refers to the seam that forms between concrete poured in stages due to design requirements or construction needs during the concrete pouring process, between the concrete poured first and that poured later. A construction joint is not an actual “joint”; it is merely a interface that exists between the concrete poured first and the concrete poured later, as the former sets before the latter is poured, and this interface is what is referred to as a construction joint. Principles: (1) Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beams, above the crane beams, and below the column caps of beamless floor slabs. ⑵ For large-section beams that are integrated with the floor slab, construction joints should be placed 20 mm to 30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is left below the beam support. ⑶ For one-way slabs, construction joints should be placed at any position parallel to the short side of the slab. ⑷ For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. ⑸ The construction joint on the wall should be located within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. ⑹ The construction joint on the stairs should be located at 1/3 of the tread height. ⑺ The construction joint on the pool wall should be left on the vertical wall at a height of 200 mm to 500 mm above the surface of the base slab. ⑻ For two-way stressed floor slabs, mass concrete, arches, shells, silos, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements.

　General principles for placing construction joints: The location of construction joints should be chosen in areas where the structure is subject to less shear force and where it is easier to carry out construction. The following rules should be followed: horizontal joints should be used for columns, while vertical joints should be used for beams, slabs, and walls. 　　(1) Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beam, above the crane beam, and below the column caps of slab-on-grade floors. 　　(2) For large-section beams integrated with the floor slab, the construction joint should be placed 20 mm–30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is placed below the beam support. 　　(3) For one-way slabs, the construction joint should be placed anywhere parallel to the short side of the slab. 　　(4) For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. 　　(5) The construction joint on the wall should be placed within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. 　　(6) The construction joint on the stairs should be located at 1/3 of the tread height. 　　(7) The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. 　　(8) For floor slabs subjected to bidirectional loads, mass concrete, arches, shells, tanks, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements

　General principles for placing construction joints: The location of construction joints should be chosen in areas where the structure is subject to less shear force and where it is easier to carry out construction. The following rules should be followed: horizontal joints should be used for columns, while vertical joints should be used for beams, slabs, and walls. 　　(1) Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beam, above the crane beam, and below the column caps of slab-on-grade floors. 　　(2) For large-section beams integrated with the floor slab, the construction joint should be placed 20 mm–30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is placed below the beam support. 　　(3) For one-way slabs, the construction joint should be placed anywhere parallel to the short side of the slab. 　　(4) For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. 　　(5) The construction joint on the wall should be placed within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. 　　(6) The construction joint on the stairs should be located at 1/3 of the tread height. 　　(7) The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. 　　(8) For floor slabs subjected to bidirectional loads, mass concrete, arches, shells, tanks, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements

General principles for placing construction joints: The location of construction joints should be chosen in areas where the structure is subject to less shear force and where it is easier to carry out construction. The following rules should be followed: horizontal joints should be used for columns, while vertical joints should be used for beams, slabs, and walls. 　　 (1) Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beam, above the crane beam, and below the column caps of slab-on-grade floors. 　　 (2) For large-section beams integrated with the floor slab, the construction joint should be placed 20 mm–30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is placed below the beam support. 　　 (3) For one-way slabs, the construction joint should be placed anywhere parallel to the short side of the slab. 　　 (4) For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. 　　 (5) The construction joint on the wall should be placed within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. 　　 (6) The construction joint on the stairs should be located at 1/3 of the tread height. 　　 (7) The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. 　　 (8) For floor slabs subjected to bidirectional loads, mass concrete, arches, shells, tanks, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements

A construction joint refers to the seam that forms between concrete poured in stages due to design requirements or construction needs during the concrete pouring process, between the concrete poured first and that poured later. A construction joint is not an actual “joint”; it is merely a junction surface that exists between concrete poured earlier and concrete poured later, as the former has been poured for longer than its initial setting time. This junction surface is what is referred to as a construction joint. ??Principles:??⑴ Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beams, above the crane beams, and below the column caps of beamless floor slabs. ??⑵ For large-section beams that are integrated with the floor slab, construction joints should be placed 20 mm to 30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is left below the beam support. ??⑶ For one-way slabs, construction joints should be placed at any position parallel to the short side of the slab. ??⑷ For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. ??⑸ Construction joints on the wall should be located within 1/3 of the span of the lintel above the door opening, or they can also be placed at the junction of vertical and horizontal walls. ??(6) The construction joint on the stairs should be placed at the 1/3 point of the tread plate. ??⑺ The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. ??⑻ For floor slabs subjected to bidirectional loads, mass concrete, arches, shells, silos, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements.

A construction joint refers to the seam that forms between concrete poured in stages due to design requirements or construction needs during the concrete pouring process, between the concrete poured first and that poured later. A construction joint is not an actual “joint”; it is merely a junction surface that exists between concrete poured earlier and concrete poured later, as the former has been poured for longer than its initial setting time. This junction surface is what is referred to as a construction joint. ??Principles:??⑴ Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beams, above the crane beams, and below the column caps of beamless floor slabs. ??⑵ For large-section beams that are integrated with the floor slab, construction joints should be placed 20 mm to 30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is left below the beam support. ??⑶ For one-way slabs, construction joints should be placed at any position parallel to the short side of the slab. ??⑷ For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. ??⑸ Construction joints on the wall should be located within 1/3 of the span of the lintel above the door opening, or they can also be placed at the junction of vertical and horizontal walls. ??(6) The construction joint on the stairs should be placed at the 1/3 point of the tread plate. ??⑺ The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. ??⑻ For floor slabs subjected to bidirectional loads, mass concrete, arches, shells, silos, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements.

The location of construction joints should be chosen in areas where the structure is subject to less shear force and where construction is easier; moreover, the following rules must be followed: horizontal joints should be used for columns, while vertical joints should be used for beams, slabs, and walls.

Principles for setting construction joints: (1) Must be determined prior to pouring. (2) Principles: ① The structure experiences low shear forces ； ②Areas that are easy to work on.

General principles for placing construction joints: The location of construction joints should be chosen in areas where the structure is subject to less shear force and where it is easier to carry out construction. The following rules should be followed: horizontal joints should be used for columns, while vertical joints should be used for beams, slabs, and walls. 　　 (1) Construction joints should be placed on the top surface of the foundation, below the beams or the brackets of the crane beam, above the crane beam, and below the column caps of slab-on-grade floors. 　　 (2) For large-section beams integrated with the floor slab, the construction joint should be placed 20 mm–30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is placed below the beam support. 　　 (3) For one-way slabs, the construction joint should be placed anywhere parallel to the short side of the slab. 　　 (4) For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. 　　 (5) The construction joint on the wall should be placed within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. 　　 (6) The construction joint on the stairs should be located at 1/3 of the tread height. 　　 (7) The construction joint in the pool wall should be located on the vertical wall at a height of 200 mm to 500 mm above the surface of the bottom slab. 　　 (8) For two-way stressed floor slabs, mass concrete, arches, shells, tanks, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements.

⑴ Construction joints should be placed at the top surface of the foundation, below the brackets of beams or crane beams, above crane beams, and below the column caps of beamless floors. ⑵ For large-section beams that are integrated with the floor slab, construction joints should be placed 20 mm to 30 mm below the bottom surface of the slab. When there is a beam support under the slab, it is left below the beam support. ⑶ For one-way slabs, construction joints should be placed at any position parallel to the short side of the slab. ⑷ For floor slabs with primary and secondary beams, pouring should be carried out in the direction of the secondary beams, and construction joints should be placed within 1/3 of the span of the secondary beams. ⑸ The construction joint on the wall should be located within the middle third of the span of the lintel above door and window openings; it may also be placed at the junction of longitudinal and transverse walls. ⑹ The construction joint on the stairs should be located at 1/3 of the tread height. ⑺ The construction joint on the pool wall should be left on the vertical wall at a height of 200 mm to 500 mm above the surface of the base slab. ⑻ For two-way stressed floor slabs, mass concrete, arches, shells, silos, equipment foundations, multi-story rigid frames, and other complex structures, the locations of construction joints shall be determined in accordance with the design requirements.