resumo
Especially in rehabilitation works, the use of lime based mortars have been increasing due to the need of compatibility between the old and the new materials. The mortars fresh state properties are extremely important since determines the material workability and also have a great influence on its hardened state characteristics. In this work, the fresh state properties of aerial lime pastes and aerial lime based mortars were investigated. The torque variation with time and the mortar rheological parameters (relative yield stress and plastic viscosity) were obtained using a rheometer suitable for mortars. The correlation of rheological data with slump and relative density measurements was studied. The mortars workability is affected by several parameters, namely, the binder/aggregate and water/binder ratios. the kneading water content, the admixtures type and amount. The admixtures influence (type and amount) on the fresh state properties of aerial lime based mortars are discussed. The used admixtures were the most common ones for several mortars, such as a water-retaining agent, a plasticizer and an air-entraining agent. (C) 2008 Elsevier Ltd. All rights reserved.
palavras-chave
CEMENT-BASED MATERIALS; RHEOLOGICAL PROPERTIES; HYDRAULIC LIME; BEHAVIOR; CONSERVATION; PERFORMANCE
categoria
Construction & Building Technology; Engineering; Materials Science
autores
Seabra, MP; Paiva, H; Labrincha, JA; Ferreira, VM
nossos autores
Helena Maria da Costa Paiva
Investigador
João António Labrincha Baptista
Professor Catedrático
Maria Paula Seabra
Professor Auxiliar
Victor Miguel Carneiro de Sousa Ferreira
Professor associadoagradecimentos
The authors acknowledge the Foundation for Science and Technology (FCT-Portugal) for the financial support (grant SFRH/BPD/19482/2004) and also to Weber Cimenfix industry for raw materials supply and helpful discussions.