Mix Design Method for Coating Mixed Mortar According to Influence of the Aggregate Type and Application Environment Conditions

Abstract

No recent research was found regarding mix design for coating mortars. Those that exist (older ones) have limitations in use or specific materials. They are defined for the use of a certain equipment or specific condition and cannot be applied in other regions. An appropriate mix project needs to have a process that al-lows to obtain adequate proportions of the materials taking into account the different materials and conditions at the application site. Therefore, the aim of this paper is to propose an experimental mix design method for mixed mortars to be used in wall cladding and to study two types of most common aggregates (natural or crushing) through properties from the application sites and material characteristics. The experimental program of this study consisted in characterizing the materials and conducting necessary tests to evaluate the mix design method and how the characteristics of the aggregates influence the mixing design process, as well as the mechanical properties (flexural, compressive strength and pull off strength) and durability indicators (elasticity modulus, water absorption and porosity). We verified that the characteristics of the aggregates interfere with the properties of these composites and that the proposed method was able to capture this and define adequate proportions of the materials according to the exposure conditions. The method generated more economical (less cement consumption) and more sustainable mixed coating mor-tars (reduction of cement and lime in the mixtures, especially with artificial aggregate) without compromising the limiting properties Pull Off (0.390 MPa) and Flexural Strength (2.396 MPa). We conclude that the mix design method allows to optimize the characteristics of the mixed mortars depending on the type/characteristics of the aggregate and the conditions of the application environment.