1. Definition
Polycarboxylate superplasticizers (PCEs) are third-generation, high-performance concrete admixtures characterized by:

  • Main chain: Carboxyl group (-COOH) containing polymer backbone

  • Side chains: Polyethylene oxide (PEO) grafts

  • Functional groups: May include sulfonic, amino, or other modifying groups

2. Key Properties
(1) High water reduction: 25-40% (at typical dosage of 0.15-0.3%)
(2) Low dosage: Only 1/5-1/10 of naphthalene-based superplasticizers
(3) Excellent slump retention: 2-8 hours workability maintenance
(4) Molecular design flexibility: Tunable for specific project requirements

3. Mechanism of Action

  • Electrostatic repulsion: Carboxylate anions impart negative charge to cement particles

  • Steric hindrance: PEO side chains prevent particle agglomeration

  • Water film lubrication: Releases trapped free water

4. Product Classification

Type Characteristics Applications
Standard Balanced water reduction/slump retention Ready-mix concrete
Early-strength 30%+ higher 3-day strength Precast elements
Slow-release Low initial slump, gradual release Long-distance transport
Clay-tolerant Tolerates ≤7% clay content Manufactured sand concrete

5. Production Process
Conventional free radical polymerization:

  1. Monomer premix (acrylic acid + MPEG ester, etc.)

  2. Initiated polymerization (ammonium persulfate, 60-80°C)

  3. pH adjustment (NaOH to 6-8)

  4. Product formulation (typically 20-40% solid content)

6. Application Guidelines

  • Dosage sensitivity: Overdosing may cause bleeding/segregation

  • Cement compatibility: Requires compatibility testing

  • Temperature effects: Retarder components need adjustment in hot weather

  • Mixing restrictions: Avoid direct mixing with lignosulfonates

7. Market Status

  • China annual production: ~3 million tons (>60% global share)

  • Price range: $350-600/ton

  • Technology trends: Functionalization (self-healing, temperature-responsive, etc.)

8. Standards & Specifications

  • China: GB 8076-2008 “Concrete Admixtures”

  • International: ASTM C494 Type F/G

  • EU: EN 934-2:2009+A1:2012

For detailed information on specific aspects (e.g., molecular design, case studies), please specify your focus area for tailored technical information.