Viscoelastic behaviour of macro-defect-free cement

• Published in: Journal of materials science Vol. 29; no. 10; pp. 2683 - 2690
• Main Authors: TUN-JEN CHU, ROBERTSON, R. E
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.01.1994
• Subjects: Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Exact sciences and technology; Materials; Properties and test methods; Properties of anhydrous and hydrated cement, test methods; Viscoelasticity; Shear modulus; Cement; Mechanical properties; Property structure relationship; Microstructure; Modeling
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/BF00356818

The viscoelastic behaviour of macro-defect-free (MDF) cement was studied by dynamic mechanical analysis. MDF specimens with various moisture contents in the range 1.70%-3.20% moisture, were measured at 1 Hz as a function of temperature from 34-96 C and as a function of frequency from 0.05-5 Hz at 34 C. The viscoelasticity of MDF was found to be affected by moisture content through its plasticising effect on the PVA binder. Time-moisture and temperature-moisture superposition of the shear moduli were found to be possible for MDF, and linear relationships between log time and linear moisture and between temperature and moisture, were found. How the microstructure of MDF affects the viscoelastic response is also discussed through mechanical models. A comparison of the models with known experimental data suggests that the viscoelastic response arises from both direct connections between the inorganic particles and from connections through the polymer binder. Inorganic links are estimated to connect 45% of the inorganic phase. 21 refs.