Lightweight Strain Hardening Brittle Matrix Composites

Inventors: V.C. Li and S. Wang
US Patent No. 6,969,423
Issued on November 29, 2005

Performance Targets:

  • Lightweightedness (low density)
  • Maintain material properties (tensile and compressive strengths, tensile ductility or strain hardening)


  • Floating homes, canoe, or other structures requiring lightweight and durable construction material

Tensile behavior of two versions of Lightweight ECC
SEM Picture of Lightweight ECC Microstructure
Canoe made with Lightweight Engineered Cementitious Composite (ECC)


Suggested Key Words: Lightweight ECC, low density concrete, tensile ductility, strain hardening

Non-Proprietary Description: Lightweight fiber-reinforced brittle matrix composites combining low density and extreme tensile ductility. Compared to normal concrete, this lightweight composite has substantially improved tensile strain capacity with strain hardening behavior and self-controlled crack width, substantially improved compressive strength, improved tensile strength, and low density. The brittle matrix may be a hydraulic cement or an inorganic polymer. In an exemplary embodiment of the invention, the composites are prepared by dispersing lightweight fillers with controlled size distribution in engineered cementitious composite fresh mixture, to form a resulting mixture, then placing the resulting mixture into a mold, and curing the resulting mixture. The lightweight fillers include air voids, glass bubbles, polymeric hollow bubbles, and lightweight aggregates with sizes from 10 to 1000 micrometer.