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