Sprayable Strain-hardening Cementitious Composites

Inventors: V.C. Li, Y.Y. Kim, and H.J. Kong
Invention Disclosure UM File 2418
US Patent No. 7,241,338
Issued in July, 2007

Performance Targets:

  • Sprayability
  • Pumpability, low rebound
  • Maintain material properties (strain hardening, multiple cracking)


  • Tunnel lining repair
  • Sewage repair 
  • Other repair and retrofit


Suggested Key Words: sprayable ECC, concrete repair, tunnel repair and retrofit

Non-Proprietary Description: Fiber-reinforced, strain-hardening cementitious composites which are capable of being pneumatically sprayed in conjunction with wet spray process, can be prepared by adding polymer fibers to a cement composition containing organic/inorganic admixtures (e.g., viscosity agent and superplasticizer). Compared to ordinary spray cementitious composites including fiber-reinforced mortar or concrete, the composite according to the invention displays enhanced pumpability and rebound property. The resultant sprayed composite has substantially improved tensile strain capacity with strain hardening behavior and self-controlled crack width, substantially improved flexural deformation capacity, and improved tensile strength