【Utilities – Civil Engineering Version】20181127

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This post was last edited by hesonchang214 on 2018-11-27 at 18:29. Regarding the methods of constructing brick masonry structures, which option is correct? A. When using the mortar application method for construction, the length of the mortar applied at normal temperatures shall not exceed 800 mm. B. Staggering rods should be installed at the corners and junctions of brick masonry. C. The thickness of the horizontal mortar joints in brick masonry shall be at least 12 mm. D. Any temporary interruptions that must be created should be constructed as straight joints. 【Answer】B 【Explanation】The common key points in the construction of brick masonry structures are as follows. (1) There are four masonry methods: the \"3-1\" masonry method, the grout pressing method (grout spreading method), the grout scraping method, and the full-grout method. The “three-one” masonry method is generally recommended, that is, the method of applying one layer of mortar, placing one brick, and then pressing it down. When masonry is carried out using the grouting method, the grouting length shall not exceed 750 mm; when the temperature during construction exceeds 30°C, the grouting length shall not exceed 500 mm. (2) Install stud markers: Stud markers should be placed at the corners and junctions of brick masonry; these markers indicate the number of bricks per layer, the thickness of the mortar joints, as well as the locations where there are changes in the vertical construction. (3) The width of the mortar joints in brick walls should be 10 mm, and it should not be less than 8 mm nor more than 12 mm. (4) The corners and joints of brick walls should be constructed simultaneously; it is strictly prohibited to build the interior and exterior walls separately without reliable measures. Temporary breaks that cannot be constructed simultaneously but must be retained should be built as inclined joints, with the horizontal projection length of such inclined joints not being less than 2/3 of their height. (5) At temporary joints in areas not subject to seismic design or in areas with seismic design intensities of 6 or 7 degrees, when inclined joints cannot be used, straight joints may be employed except at corners; such straight joints must be designed as convex joints. Reinforcing bars for bonding should be installed at the joints where the walls are left straight. The number of such reinforcing bars is 6 per 120 mm of wall thickness; for walls with a thickness of 120 mm, 6 bonding reinforcing bars are required. The spacing between these bars along the height of the wall should not exceed 500 mm, and their embedment length from the joint should be no less than 500 mm on each side. In areas with seismic intensity levels of 6 or 7, this embedment length should be no less than 1000 mm ； A 90° hook should be present at the end.