Phase separation in mortars: development of evaluation method and influence on rheological behavior

• Grant number: 11/00948-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2011
• End date: March 31, 2015
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Rafael Giuliano Pileggi
• Grantee: Fábio Alonso Cardoso
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 13/27121-2 - Squeeze-flow and phase segregation in mortars: influence of paste viscosity and particle size distribution, BE.EP.PD

Abstract

During their processing, fresh mortars and concretes are submitted to diverse rheological solicitations to which they must present adequate behavior, as well as, robustness regarding phase distribution uniformity. Phase separation (segregation) can occur in different scale levels in these materials (paste, mortar and concrete), changing the rheological behavior and, hence, decreasing quality and/or processing productivity. Furthermore, phase segregation plays an important role on the rheological methods applied for the evaluation of building materials, since it influences the measurements and, strictly from the rheological point of view, invalidate such results. Therefore, this research project aims to evaluate the influence of phase separation on the rheological behavior of heterogeneous cement suspensions. The two-year experimental chronogram consists of (1) developing a method for quantification of phase separation induced in different situations; (2) evaluating the influence of phase separation on the squeeze-flow and rotational rheometry techniques; (3) determining the phase separation tendency of diverse materials; and (4) identifying the causes for the rheological and segregation behaviors through the correlation of the obtained results with the formulation characteristics of the tested materials.

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CARDOSO, FBIO A.; FUJII, ALESSANDRA L.; PILEGGI, RAFAEL G.; CHAOUCHE, MOHEND. Parallel-plate rotational rheometry of cement paste: Influence of the squeeze velocity during gap positioning. CEMENT AND CONCRETE RESEARCH, v. 75, p. 66-74, SEP 2015. (11/00948-9, 12/18952-5, 13/27121-2)

GRANDES, FRANCO A.; SAKANO, VICTOR K.; REGO, ANDRESSA C. A.; CARDOSO, FABIO A.; PILEGGI, RAFAEL G.. Squeeze flow coupled with dynamic pressure mapping for the rheological evaluation of cement-based mortars. CEMENT & CONCRETE COMPOSITES, v. 92, p. 18-35, SEP 2018. (11/00948-9, 12/18952-5)

GRANDES, FRANCO A.; SAKANO, VICTOR K.; REGO, ANDRESSA C. A.; REBMANN, MARKUS S.; CARDOSO, FABIO A.; PILEGGI, RAFAEL G.. Rheological behavior and flow induced microstructural changes of cement-based mortars assessed by Pressure Mapped Squeeze Flow. Powder Technology, v. 393, p. 519-538, NOV 2021. (11/00948-9, 14/50948-3, 12/18952-5)

COSTA, E. B. C.; CARDOSO, F. A.; JOHN, V. M.. Influence of high contents of limestone fines on rheological behaviour and bond strength of cement-based mortars. CONSTRUCTION AND BUILDING MATERIALS, v. 156, p. 1114-1126, DEC 15 2017. (11/00948-9, 10/10843-7)