The nature of limestone filler and self-consolidating feasibility—Relationships between physical, chemical and mineralogical properties of fillers and the flow at different states, from powder to cement-based suspension

Abstract

The nature of limestone filler and self-consolidating feasibility Relationships between physical, chemical and mineralogical properties of fillers and the flow at different states, from powder to cement-based suspension. a b s t r a c t Keywords: Powder flow Tribo-electrification Shear of powder Rheological test Kendall's coefficients Wet packing densityThis paper is a part of a large study aimed at identifying the physical and chemical properties of limestone fillers (LF) that govern their behaviour towards self-consolidating flow. Five LF were studied, complying with the standards and selected for their significant differences in properties on the basis of the supplier's database. Despite their specific manufacturing, a thorough characterization showed that the selected LFs had very different properties in terms of surface charges, morphology, wettability and size distribution. Then, relationships were sought between these properties and the flow of LF in powder form and suspended in water, or water + polycarboxylate type High Range Water Reducer Admixture (HRWRA), or water + HRWRA + cement (OPC or slag blended cement). The flow measurements concerned flowability, floodability and shear under consolidation in the dry state, and static yield stress and apparent viscosity in the suspension state. The main results show that the LFs act in the same way on the flow as long as cement is not incorporated into the suspension. From the dry state to the water + HRWRA suspensions, the flow is dependent on the fineness of the LF. The significant relationships between the surface charges, wettability and fineness of LFs show that impurities like clays are key factors in the flow of LF suspensions. When cement was incorporated into the suspension, the flow was dependent on the interactions existing among all the constituents. Then, with a view to self-consolidating applications, it becomes possible to identify how best to incorporate LF in a cement-based matrix through the measurement of the arrangement of cement and filler particles in suspension.

Formation of C-S-H in calcium hydroxide–blast furnace slag–quartz–water system in autoclaving conditions

“…In addition, the excessive grinding promotes the formation of electrostatic charges of particles, which produces flocculation. As with the cement case, the phenomenon of over-grinding leads to flocculation phenomena attributed to electrostatic charges, which agglomerate the extremely fine particles (Diederich et al, 2012). In addition, the hydration product of the mechanically activated slag depends not only on the initial specific surface area of the slag but also on the surface activation, as manifested by the change in the zeta potential of the slag during the milling process (Kumar et al, 2005).…”

Rheology of Alkali-Activated Mortars: Influence of Particle Size and Nature of Aggregates

“…The following tests were conducted in the different mortars: 4, and voids content as per Equations (5) and (6) for each mortar [38][39][40];…”

Rheology of Mortar With Portland-Limestone Cement Cem Ii/A,b-Ll in Relation to Properties of Cement

“…Authors of works [3,10] showed a decrease in the yield stress and an increase of plastic viscosity with an increase in the limestone content. The results of tests are usually only related to the chemical and physical properties of limestone, whereas the influence of clinker or Portland cement itself is rarely taken into account [3,8,9,11]. Seeing as rheological properties of the mortars and concrete mixes are important for predicting the workability and workability loss in time, this discrepancy should be a subject of further in-depth research.…”