International Concrete Abstracts Portal

Title: Nanomechanical properties of cement paste

Author(s): Fernando Pelisser, Philippe J.P. Gleize, Milton Domingos Michel

Publication: IBRACON

Volume: 4

Issue: 4

Appears on pages(s): 561 567

Keywords: Nanoindentation, cement paste, elastic modulus.

DOI:

Date: 10/10/2011

Abstract:
Understanding the influence of each phase of concrete, among which cement paste deserves prominence, is important for the development of a more efficient concrete, with an improved hydration process and resistance to plastic shrinkage cracks. The elastic modulus of the concrete is one of the principal project parameters of structures and they have extensive influence on the speed of the construction process and durability of the structures. The capacity for deformation of the concrete depends on the intrinsic characteristics of the cement hydration products, aggregates, transition zone and pores, besides variables inherent to the process, including the speed of hydration and climatic conditions. The aim of this research was to analyze the mechanical properties of the elastic modulus and hardness of a cement paste, through the nanoindentation technique and compare these using the conventional method for concrete. The results obtained for the nanostructure of cement pastes presented mean elastic modulus values of 17.9 GPa and 0.90 GPa for hardness. Determination of the elastic modulus calculated by NBR 6118 [1] was 9.6 GPa. Nanoindentation proved to be a valid method for evaluating nanostructure modifications in cement pastes.