Influence of metakaolin on the properties of mortar and concrete: A review

The origin of the pozzolanic activity of calcined clay minerals: A comparison between kaolinite, illite and montmorillonite

Metakaolin as cementitious material: History, scours, production and composition – A comprehensive overview

Development of a new rapid, relevant and reliable (R3) test method to evaluate the pozzolanic reactivity of calcined kaolinitic clays

The pozzolanic activity of calcined clays depends on the type and amount of clayed minerals, the nature and amount of impurities, the thermal treatment used for its activation and the specific surface obtained after calcination. In this paper, four test methods for assessment the pozzolanic activity on seven calcined clays (five kaolinites and two bentonites) were analyzed. Natural clays were calcined and investigated by two direct tests (Frattini and saturated lime) and two indirect tests (strength activity index and electrical conductivity). Frattini test and the strength activity index (SAI) were found to be the most accurate and reliable methods to assess pozzolanic activity over time. Frattini test evaluates accurately the calcium hydroxide (CH) consumption by pozzolanic reaction, and SAI test discriminates the real contribution of pozzolanic reaction to densification of microstructure. The electrical conductivity (EC) and the lime consumption (LC) tests evaluate the ability of pozzolanic material to fix CH during the first time of contact and their results are correlated with the specific surface of calcined clay.

Assessment of pozzolanic activity of different calcined clays

The effect of dehydroxylation/amorphization degree on pozzolanic activity of kaolinite

The influence of the chemical and phase composition of different mineral admixtures on pozzolanic activity was studied. Local kaolin clay, activated kaolin clay, porcellanite, activated porcellanite, pumice, fly ash, silica fume and ground quartz were used as components of blended binders for various mortars. Thermal treatments were performed as a means for activation of the minerals. The phase transformations during heat treatment were studied by X-ray diffraction services (XRD) and differential thermal analysis/thermogravimetric analyses (DTA/TGA). The pozzolanic activity of these materials as a function of heat treatment parameters was investigated.

A. Shvarzman

Papers

The effect of dehydroxylation/amorphization degree on pozzolanic activity of kaolinite

Influence of chemical and phase composition of mineral admixtures on their pozzolanic activity