Invention Title: Lightweight Strain-hardening Brittle Matrix Composites

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.

SEM Picture of Lightweight ECC Microstructure

Tensile Behavior of Two Versions of Lightweight ECC

Lightweight ECC Canoe