Other hydraulic cements
Portland cement, aluminous cement, slag cement, supersulfate cement and similar hydraulic cements, whether or not colored or in the form of clinkers: > Other hydraulic cements
Duty Rate (from China)
Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Products classified under HTS 2523.90.00.00
High Alumina Cement
High alumina cement is a hydraulic cement produced from bauxite and limestone, capable of setting and hardening underwater or in air due to its aluminous composition. It falls under HTS 2523.90.00.00 as 'other hydraulic cements' distinct from Portland, slag, or supersulfate types. Primarily used in refractory applications and rapid-strength concrete.
Calcium Aluminate Cement
Calcium aluminate cement is a specialized hydraulic binder with high early strength, made from limestone and alumina-bearing materials. Classified in HTS 2523.90.00.00 as other hydraulic cements, not fitting Portland or supersulfate categories. Ideal for sewer pipe linings and aggressive chemical environments.
Supersulfated Cement Powder
Though related to slag cements, certain supersulfated formulations with unique gypsum-calcium sulfate ratios qualify as 'other' under HTS 2523.90.00.00. This hydraulic cement develops strength through sulfate reactions, suitable for marine structures. Excluded from pure slag cement (2523.28) by composition specifics.
Roman-Type Hydraulic Cement
Replicated pozzolanic hydraulic cement using volcanic ash and lime, sets underwater like ancient Roman opus caementicium. HTS 2523.90.00.00 as other hydraulic due to blended hydraulic properties. Applied in marine and archaeological restoration.
Colored Hydraulic Lime Cement
Hydraulic lime cement with iron oxide pigments for aesthetic matching in restoration, hydraulically sets via free lime. Classed HTS 2523.90.00.00 as other colored hydraulic cement. Not excluded by chapter notes on earth colors.
Pozzolanic Hydraulic Cement Blend
Blend of Portland clinker (<50%), fly ash, and gypsum creating hydraulic set via pozzolanic reaction. HTS 2523.90.00.00 for such composite other hydraulics. Sustainable alternative for low-carbon concrete.
Sorel Cement Powder
Magnesium oxide-based hydraulic cement (Sorel) that sets with magnesium chloride solution, used for flooring. Though chemically distinct, classified HTS 2523.90.00.00 as other hydraulic when sold as powder. Not magnesium oxide crystals excluded by chapter note.
Expansive Hydraulic Cement
Specially formulated hydraulic cement with ettringite-forming agents to counteract shrinkage in concrete. HTS 2523.90.00.00 as other hydraulic cement with unique properties. Used in prestressed concrete and crack control.
Masonry Hydraulic Cement
Masonry hydraulic cement blends natural cement with limestone for tuckpointing and restoration work, setting hydraulically. HTS 2523.90.00.00 covers this as other hydraulic cement, distinct from standard Portland. Colored variants for matching historic brickwork are common.
Natural Cement Clinker Ground
Ground natural cement from argillaceous limestone kilns provides hydraulic setting like Roman concrete. Under HTS 2523.90.00.00 as other hydraulic cements, separate from synthetic Portland. Used in sustainable historic replication projects.