Page 171 - Water Standards
P. 171

and  uniformly.  If  pouring  is  interrupted, the
                                   construction surface shall be chiseled into a radial joint
                                   surface. When the bottom arch is constructed with a
                                   pulling formwork, there shall be measures to prevent
                                   floating.
                           Table 3   5   3  Maximum dip angle of belt conveyor for concrete

                         Concrete slump (cm)  Upward transportation  Downward transportation
                               <5                 16°                 8°
                              5-10                14°                 6°
                              10-16               12°                 4°
                       3   5   4    Masonry ( rock material, concrete precast block ) lining
                       shall meet the following requirements:
                           1  Masonry construction shall be in accordance with the regula⁃
                       tions in Section 2   8 of this specification. The staggered distance of
                       vertical joints in the upper and lower layers of a side wall shall not be
                       smaller than 10cm. The overbreak part behind the sidewall shall be
                       filled up with masonry.
                           2  When the arch ring is built by the method of “ wall before
                       arch ”, T⁃shape stones shall be extended out or holes left for
                       supporting the ring frame which can also be supported by pillars.
                       Rocks or precast blocks shall be laid symmetrically from both sides of
                       the arch foot, and the overbreak part of the arch roof shall be filled
                       up densely.
                           3  When the arch ring is built by the method of “ wall after
                       arch”, reinforced concrete joists shall be poured at the arch feet to
                       support the arch ring.
                       3   5   5  The lining of concrete precast components shall meet the fol⁃
                       lowing requirements:
                           1  Component blocking: the lateral or longitudinal width of the
                         1 6 4
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