Testing of Composite Mortars Based on Supplementary Cementitious Materials: Estimating Durability and Thermal Properties

Abstract

The growing need for building material resources, and the requirements to preserve the environment, in a vision of sustainable development, has become necessary to study reinforcement techniques, using composite materials. Using local organic or inorganic materials in construction fields and public works is particularly important. Polymer mortar composites (PMC) are usually employed in the building industry as finishing materials, tile adhesive (mortar-adhesive) or façade coating. In repair applications, the addition of soluble polymer (latex) allows improving the adhesion properties of the materials used as coating. The use of mineral additives as partial substitutes for cement, in construction sites as well as in ready-to-use mortars, is an unknown practice in our country. For this reason, we thought it is crucial to study and assess the influence of these additions on the properties of cured composite. Supplementary cementitious materials (SCM) used in this study are silica fume and natural pozzolan, which necessarily need to be valorized.The present research work aims to use a specific experimental methodology that is able to identify the relationship between the degree of substitution by the mineral additives, the polymer and the modifications to the properties of fresh and hardened cement mixtures. Therefore, five PMC combinations were formulated from different percentages of additions, i.e. natural pozzolan (NP: 25%w), silica fume (Sf: 5%w) and polymer latex (P: 0, 5, 7.5, 10, 12.5 and 15%w). Their durability factors, such as the porosity accessible to water and capillary absorption rate (sorptivity), were characterized, at different maturities. An attempt was also made to determine the thermal coefficients. The results obtained were compared with those of the reference mortars, made with Portland cement (CEMI). They showed that the decrease in porosity, sorptivity and thermal conductivity depends on the pair “SCMs/polymer”. But overall, the addition of polymer latex and pozzolanic additions have a beneficial effect on the durability and thermal properties of the composite materials.

The thermal properties of mortars modified by the effect of combining polymers and SCMs

“…These results could be attributed to the overall porosity of the cementitious matrix, to the density decline of the polymer-based composite (lightness of the composite mortar), and especially to the formation of the polymer film (Belbachir, 2017). These results corroborates with those obtained by Latroch et al (2016).…”

“…The thermal insulating effect of Latex polymer is most attractive and indicates a high and promising potential for development. These results corroborates with those obtained by Latroch et al (2016).…”

“…Their thermal properties are therefore better. As a result, several authors (Aattache et al, 2013;Benosman et al, 2013;Elalaoui, 2012a,b;Fu et al, 1997;Latroch et al 2016) reported that the thermal conductivity decreases as the polymer content in the composite increases. Because, the thermal conductivity of the polymer is lower than plain cement or SCMs.…”

Durability of mortars modified by the effect of combining SPA polymers and supplementary cementitious materials

“…Certaines proportions clés sont également étudiées, contrairement à ce qui a été entrepris dans les travaux antérieurs [5,[7][8][9][10][11][12]. Un complément d'information sur la microstructure a été effectué par la spectrométrie IRTF.…”

Durability of mortars modified by the effect of combining SPA polymers and supplementary cementitious materials

“…Le but de cette étude est de présenter les résultats d'un travail de recherche portant sur la durabilité des mortiers composites à base de l'effet de la combinaison de l'ajout du polymère SPA et des SCMs telles que la pouzzolane naturelle et la fumée de silice, comme substituant au ciment et ceci pour la réalisation des mortiers de réparation conçus au développement durable. Certaines proportions clés sont également étudiées, contrairement à ce qui a été entrepris dans les travaux antérieurs [5,[7][8][9][10][11][12]. Un complément d'information sur la microstructure a été effectué par la spectrométrie IRTF.…”