Effect of gypsum content in sprayed cementitious matrices: Early age hydration and mechanical properties

Author(s)

Herrera-Mesen, C. ^[1] ; Salvador, R. P. ^[2] ; Cavalaro, S. H. P. ^[3] ; Aguado, A. ^[1]

Affiliation

^[1] Univ Politecn Cataluna, Dept Civil & Environm Engn, Barcelona Tech, UPC, Jordi Girona 1-3, Barcelona 08034 - Spain

^[2] Univ Sao Judas Tadeu, Dept Civil Engn, 546 Taquari St, BR-03166000 Sao Paulo - Brazil

^[3] Loughborough Univ, Sch Architecture Bldg & Civil Engn, Loughborough LE11 3TU, Leics - England

• Document type: Journal article
• Source: CEMENT & CONCRETE COMPOSITES; v. 95, p. 81-91, JAN 2019.
• Web of Science Citations: 2

Abstract

Sprayed materials must present short setting times and a fast early strength development for safety and productivity reasons. In order to improve these characteristics, the construction industry has focused on the development of new formulations of accelerators. Research and improvement of other components of the mix, such as cement or additions, have not advanced at the same rate despite being also crucial for the reaction kinetics. The objective of this work is to evaluate the influence of gypsum content on the hydration and mechanical strength development in sprayed mixes. Sprayed pastes and mortars were prepared with one type of cement, two types of accelerators and different gypsum contents. Kinetics, mechanisms of hydration and mechanical properties were evaluated. Results showed a better performance in sprayed mixes that contain ideal doses of gypsum. Such approach provides valuable information for the improvement of the formulation of cement used in sprayed concrete applications. (AU)

• FAPESP's process: 17/00125-9 - Characterization of chemical properties, mechanical performance and durability of sprayed concrete
• Grantee: Renan Pícolo Salvador
• Support Opportunities: Scholarships in Brazil - Post-Doctoral