【Daily Discussion】Utilities - Civil Engineering - 20210424

Analysis of B and C: 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 left in columns and walls, while the concrete for beams and slabs should be poured in one go, without leaving any construction joints. 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 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 placed within 1/3 of the span of the lintel above the door opening, or they can also be located at the junction of vertical and horizontal walls. ⑹ The construction joint on the stairs should be located at 1/3 of the tread height. 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 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.

B. Location convenient for construction C. Location with minimum shear force E. Location with minimum bending moment