Performance as for watertightness of rendering mortars using admixtures
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(2021) 6:2
RESEARCH ARTICLE
Performance as for watertightness of rendering mortars using admixtures Valéria Costa de Oliveira1 · Jayson Pereira Godinho2 · Kátia Jocasta Ortiz Grings3 · Rafael Alves de Oliveira4 · Emilio Gabriel Freire dos Santos5 Received: 30 July 2020 / Accepted: 21 October 2020 © Springer Nature Switzerland AG 2020
Abstract Moisture problems when they arise in buildings, always bring discomfort, and degrade the building over time. It is worth mentioning that the Brazilian technical standard for the performance of residential buildings, presents the requirement of watertightness, in external vertical sealing systems. However, this standard does not specify mortar renderings in terms of watertightness. The standard that classifies mortar renderings recommends the determination of water absorption by capillarity and capillarity coefficient but does not include parameters for use in projects. In 2020, the Brazilian Association of Technical Standards published a technical standard selecting three main admixtures used in inorganic mortars, identified as water-reducing admixtures, air-entraining admixtures and auxiliary adhesion and flexibility polymers. Thus, it appears that the national standards for constructive performance, the standard for mortar renderings and the standard for mortar admixtures no correlation is proposed in that context, thus directing the sealing and renderings systems in isolation. Thus, the main objective of this work is to search for mortar dosages that have low water permeability in rendering systems. The adopted methodology used admixtures air-entraining admixtures, waterproofing admixtures, and hydration stabilizing admixture in the renderings mortars, correlating them to the capillarity coefficients of each mortar produced with the different admixtures. The results showed that the admixtures, of different chemical bases, commercialized for use in the production of mortars, influence the performance of the renderings when subjected to water absorption. In this context, it appears that Brazilian technical standards need correlation between them to ensure the durability of buildings. Keywords Performance · Watertightness · Renderings mortars · Admixtures · Capillarity coefficient
1 Introduction The vertical sealing of buildings performs several functions, besides watertightness [1, 2], because the actions of water when they appear in buildings, always bring discomfort, and degrade the construction over time. Moisture not only causes anomalies, but also acts as a necessary means for
most pathological manifestations to occur in buildings, such as efflorescence, rust, mold, loss of paint and mortars and even the cause of structural accidents [3]. Thus, to ensure watertightness, it is necessary to design the waterproofing of the walls in contact with the ground or subject to water infiltration, without prejudice to the use of the building and similar systems. It is noteworthy that
* Valéria Costa de Oliveira [email protected]
1
Instituto Federal de
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