Determination of particle size, surface area, and shape of supplementary cementitious materials by different techniques

Abstract

The particle size distribution, surface area and shape are fundamental characteristics of supplementary cementitious materials (SCMs). Accurate measurement of these properties is required in computational efforts to model the hydration process, and the characterization of these parameters is also an important practical issue during the production and use of blended cements. Since there are no standard procedures specifically for the determination of physical properties of SCMs, the techniques that are currently used for characterizing Portland cement are applied to SCMs. Based on the fact that most of the techniques have been developed to measure cements, limitations occur when these methods are used for other materials than cement, particularly when these have lower fineness and different particle shape and mineralogical composition. Here, samples of fly ash, granulated blast furnace slag and silica fume were tested. Different results obtained using several methods for the determination of specific surface area are presented. Recommendations for testing SCMs using air permeability, sieving, laser diffraction, BET, image analysis and MIP are provided, which represent an output from the work of the RILEM Technical Committee on Hydration and Microstructure of Concrete with Supplementary Cementitious Materials (TC-238-SCM).

Synthesis of stoichiometrically controlled reactive aluminosilicate and calcium-aluminosilicate powders

“…The surface areas measured for the calcium-aluminosilicate powders an order of magnitude higher than those typically observed for ground granulated blast furnace slag (typically 0.2 -0.8 m 2 /g) [11,35], while the pore size distribution data for all calcium-aluminosilicate powders indicate a distribution of pore sizes centred at approximately 60 -70 nm for low-Ca samples C and E, and 20 -50 nm for highCa samples D and F.…”

Ability of Two Dam Fine-Grained Sediments to be Used in Cement Industry as Raw Material for Clinker Production and as Pozzolanic Additional Constituent of Portland-Composite Cement

“…The high SEP carbonate content (calcite and dolomite) presented [50]. BET is known to be more influenced than the air-permeability methodology by surface roughness, open porosity and micro-cracks [11,51]. Considering helium pycnometry density value, it can be observed that SEP is denser than STA.…”

Investigation of heat exchange in a blown dense layer of granular materials

“…First, the main geometric characteristics of the layer and particles were evaluated. Important characteristics of the layer of granular materials that are necessary for calculating thermal characteristics of the heat exchange process and analyzing the results obtained are as follows: porosity ε of the layer and the equivalent particle diameter e d [14]. It was established that the claydite layer porosity ε k =0.47, porosity of the gravel layer ε r =0.5.…”

“…The f i factor which characterizes deviation of the particle shape from spherical shape is equal to one for balls and can be found according to recommendations of [14] for particles of other shapes as follows:…”