Influence of the Parameters of Formulation on the Fresh Properties of Cementing Materials with Admixtures

Abstract

The use of mineral admixtures in cementing materials can generate significant modifications in the fresh and hardened mixes, which can depend on the parameters of formulation. To study the influence of the parameters of formulation on the rheological properties of cementing materials with admixtures, we used seven admixtures different by their mineralogical natures, their fineness, and their morphological characteristics, two types of cements and two types of superplasticizers. The experimental methodology used is based on the volume substitution of the cement by admixtures in mixtures whose the absolute volume of the solid phases and workability are preserved constant. The main results achieved showed that the rheological properties of the fresh mortars with admixtures are very influenced by the amount and the properties of admixtures, and the nature of the superplasticizer, but depended rather on the nature of the cement used.

Valorization of Local Mineral Admixtures in Concretes

“…The action of the studied admixtures could cause a decrease or an increase in the consistency of concretes. These favorable or unfavorable effects on the rheological properties of fresh concretes, depended on the nature, quantity and granular characteristics (fineness and morphology) of the admixtures in the mixtures [1,[3][4]9]. In what follows, we used in the reference concretes a quantity of water lower than that required for mixing concretes with admixtures with a favorable granular effect on the rheological properties.…”

“…These modifications depend on several parameters such as, the nature, quantity and fineness of the incorporated admixture, as well as nature of cements and super-plasticizers used [8][9][10][11][12][13][14]. In this study, the main objective is to evaluate the benefit of mineral admixtures and super-plasticizers on the fresh and hardened properties of concretes.…”

“…We could show that the combined use of mineral admixtures with super-plasticizers in mortars could have a positive contribution on compressive strengths. [4,[9][10]. For the used admixtures, the contribution of the mineral admixtures and super-plasticizers, compared to the reference mortar, remained favorable up to 20% of the rate of cement substitution for limestone and pozzolan admixtures with fineness more than 5000 cm²/g.…”

Influence of the Parameters of Formulation on the Chemical Activity of Admixtures in Mortars

“…In purpose of allowing more accurate assessment of the own chemical activity of each admixture, which influence the mechanical properties of the cementing materials, we had to master the granular effect and to maintain constant the compactness of the solid skeleton of the mixtures with admixtures [1][2][3]. To ensure these conditions, the effects as defined were evaluated by following a specific experimental methodology based on three essential conditions:…”