Internal Viscoelastic Modulus Associated with Autogenous Shrinkage in Cementitious Materials

Abstract

The principal objective in this paper is to determine the internal viscoelastic modulus associated with autogenous shrinkage of cementitious materials. This is accomplished by analyzing autogenous shrinkage of plain and reinforced paste and mortar specimens. The internal restraint from steel reinforcement creates uniaxial tensile stress condition increasing with shrinkage. Data analysis demonstrates a unique internal shrinkage modulus, which eliminates the need for stress relaxation modulus calculations. The internal modulus is in the range of 8000-9000 MPa, while the external composite modulus known as Young’s modulus is 32 000-36 000 MPa for the low water-binder ratio (0.35) concrete.