What are assembled / segmental trapezoidal drainage channel moulds?
These moulds cast the separate concrete lining pieces of a trapezoidal farm or roadside drainage ditch: a base slab (底板), two side slabs (边板, the left and right sloped walls) and optional coping / cap stones (帽石) along the top edge. The pieces are precast in the factory and assembled on site to form a lined trapezoidal channel. This is different from a one-piece U-channel mould (see our U-drain channel page), which forms the whole trough in a single pour. Assembled liners are used for larger ditches — top openings from 100cm up to 320cm — where a one-piece mould would be too big to transport and demould.
How do I specify a set — what do 'opening / base / depth' mean?
Each complete set is defined by its finished trapezoidal cross-section: top opening (上口, the width at the top), base width (下口/底宽, the flat bottom) and depth (深度). For example the 2025-180 set is opening 180cm / base 60cm / depth 60cm; the 2025-240 is opening 240 / base 60 / depth 60; the 2025-320 is opening 320 / base 80 / depth 80. Send the ditch cross-section drawing or these three figures plus the per-piece wall thickness, and we confirm the base-slab, side-slab and coping mould sizes that build it.
Do I order a 'set' or separate piece moulds?
A run of ditch needs all three piece types: base slabs for the floor, side slabs for the two sloped walls (counted per linear metre of each slope), and coping if the top edge is capped. The set photos show how the pieces fit; the moulds themselves are sold per piece type — e.g. a base-slab mould 68×50×10, a side-slab mould 98×50×10. Order the base mould once and run enough pours for the floor length, plus the side moulds for both slopes, plus the coping mould if used. We can quote the mould kit for a given opening/base/depth and tell you the piece count per metre.
What is the difference between the 2025-180A and 2025-180B sets?
Both build an opening-180 / base-60 / depth-60cm ditch, but the base slab is designed differently: 180B uses a base slab 68×50×10cm with side slabs 98×50×10, while 180A uses a thicker profiled base 41.5×40×11.5-8.3cm (a drafted section, 11.5 tapering to 8.3) with 40×40×8 side slabs. They are two moulding arrangements for the same finished cross-section — the choice depends on your preferred piece layout and reinforcement. Send the drawing; we match it to A or B rather than assuming.
Are the side slabs left / right handed?
The trapezoidal side slabs are cast from side-specific moulds — a left-side and a right-side piece meet at the base (the 2025-18 and 2025 sets list 'left side slab' and 'right side slab' separately, e.g. left 58.6×40×10 and right 78.5×40×10). A left piece cannot be used as a right piece. Order both left and right side-slab moulds for a complete lining; the base-slab and coping moulds are not handed.
What are the L-shaped channel slabs for?
The L-shaped channel slab (L形水沟板, e.g. 85×40×39-10 or 74×40×39.5cm) combines the base and one wall in a single L-section piece — used where the ditch runs against a wall or road edge and only one sloped side is needed, or for small edge drains. It is an alternative to the three-piece trapezoidal set, not a replacement part for it. Tell us if the drain is free-standing (use trapezoidal set) or against a wall/kerb (L-shaped pieces may suit).
What does '8.3' or a size like '41.5×40×11.5-8.3' mean?
These slabs have a drafted (tapered) wall for demoulding, so the thickness is given as two figures — 11.5cm tapering to 8.3cm on the profiled base, or the standard 8.3cm wall on the 2025 sets. The taper is a designed draft angle, not a tolerance. Single-piece slabs are quoted at their nominal thickness (6, 7, 8, 8.3, 10 or 12cm depending on the ditch size and load). Wall thickness should follow the design load — roadside ditches subject to vehicle load need thicker walls and reinforcement regardless of the hydraulic section.
What concrete, material and lead time apply?
C25–C30 concrete with vibration and standard curing; larger roadside/road-crossing ditches should be reinforced. The moulds are PP for standard slabs (150+ pours); large or deeply-profiled pieces (the 2025-240/320 thick bases, R100 curved side pieces) suit ABS for stiffer walls. Mixed-SKU orders have no strict MOQ; custom cross-sections are made to order in 15–30 days after drawing approval. Send the ditch cross-section, linear metres, piece layout and destination port for an FOB Ningbo/Shanghai quote.
