I. Process Sequence

1. Mature Overlap Joint: (Traditional Process)
1) Single-width rubber sheet is vulcanized to produce mature rubber board.
2) Cutting, sanding the joint surface, and applying adhesive.
3) Multiple widths of material are overlapped and vulcanized a second time to form a whole.
2. Raw Overlap Joint: (New Process)
1) The middle part of a single-width rubber sheet is vulcanized, with unvulcanized raw rubber edges left on both sides.
2) The raw rubber edges are overlapped in a stepped manner.
3) Only the joint area is vulcanized in a single step.

II. Structural Thickness

1. Cured Overlap Joint: The joint thickness is 1.5-2 times that of the dam body. The surface is raised, uneven, and has obvious ridges. A flat plate is required for installation. The rubber strip is prone to curling at the edges and uneven color.
2. Raw Overlap Joint: Stepped complementary overlap, joint thickness consistent with the dam body, smooth and flat surface, no protrusions, no need for shims, smooth anchoring, no warping, and no color difference.

III. Strength and Durability

1. Cured Overlap Joint: Secondary vulcanization easily damages the internal skeleton canvas, reducing joint strength; stress concentration, poor vibration and fatigue resistance, and prone to seepage.
2. Raw Overlap Joint: One-time vulcanization molding, intact and undamaged internal skeleton, higher tensile and peel strength; uniform stress distribution, excellent aging resistance, vibration resistance, and fatigue resistance, with extremely low probability of seepage.

IV. Applicable Scenarios

1. Cured Overlap Joint: Small and medium-sized rubber dam projects, conventional projects with low budgets and low requirements for dam body flatness.
2. Raw Overlap Joint: Large high dams, key water conservancy projects, high-standard projects with high requirements for service life, seepage prevention, and flatness.