The current widespread use of calcium silicate or aluminate hydrate binder systems in the construction industry finds its roots in the Antique world where mixtures of calcined lime and finely ground reactive (alumino-)silicate materials were pioneered and developed as competent inorganic binders. Architectural remains of the Minoan civilization (2000-1500 BC) on Crete have shown evidence of the combined use of slaked lime and additions of finely ground potsherds to produce stronger and more durable lime mortars suitable for water-proof renderings in baths, cisterns and aqueducts (Spence and Cook 1983). It is not clear when and where mortar technology evolved to incorporate volcanic pumice and ashes as a functional supplement. A plausible site would be the Akrotiri settlement at Santorin (Greece), where archeological indications of strong ties with the Minoan culture were found and large quantities of suitable highly siliceous volcanic ash were present. This so-called Santorin earth has been used as a pozzolan in the Eastern Mediterranean until recently (Kitsopoulos and Dunham 1996). Evidence of the deliberate use of this and other volcanic materials by the ancient Greeks dates back to at least 500-400 BC, as uncovered at the ancient city of Kamiros, Rhodes (Efstathiadis 1978; Idorn 1997). In the subsequent centuries the technological knowledge was spread to the mainland (Papayianni and Stefanidou 2007) and was eventually adopted and improved by the Romans (Mehta 1987). The Roman alternatives for Santorin earth were volcanic pumices or tuff found in neighboring territories, the most famous ones found in Pozzuoli (Naples), hence the name pozzolan, and in Segni (Latium). Preference was given to natural pozzolan sources, but crushed ceramic waste was frequently used when natural deposits were not locally available. The exceptional lifetime and preservation condition of some of the most famous Roman buildings such as the Pantheon or the Pont du …

Supplementary Cementitious Materials

Compositions and methods for manufacturing composite laminate structures incorporating sheets having a moldable matrix are disclosed. Suitable compositions are prepared by mixing together a water dispersable organic binder, water, and appropriate additives (such as aggregates and fibers) which impart predetermined properties so that a sheet formed therefrom has the desired performance criteria. The compositions are formed into sheets by first extruding them into a sheet and then calendaring the sheet using a set of rollers. The calendered sheets are dried in an accelerated manner to form a substantially hardened sheet. The drying process is performed by heated rollers and/or a drying chamber. The inorganically filled sheets so formed may have properties substantially similar to sheets made from presently used materials like paper, cardboard, polystyrene, or plastic. Such sheets can be rolled, pressed, scored, perforated, folded, and glued before or after being incorporated into composite laminate structures. Such composite laminate structures have especial utility in the mass production of containers, particularly food and beverage containers.

Articles of manufacture and methods for manufacturing laminate structures including inorganically filled sheets

Mechanisms and Parameters Controlling the Tricalcium Aluminate Reactivity in the Presence of Gypsum

6 – Hydration, Setting and Hardening of Portland Cement

10 – Pozzolana and Pozzolanic Cements

Tricalcium aluminate hydration in the presence of lime, gypsum or sodium sulfate

Combined effect of lignosulfonate and carbonate on pure portland clinker compounds hydration. I. Tetracalcium aluminoferrite hydration

The influence of calcium sulfate on the hydration of 3CaO· Al2O3 in the presence of Ca(OH)2 was studied using conduction calorimetry, differential thermogravimetry, and X-ray diffraction. Sodium sulfate was also used instead of calcium sulfate. A substantial retardation of tricalcium aluminate hydration in the presence of sulfate occurs only when calcium sulfate is used and enough ettringite is formed. When ettringite disappears due to the consumption of gypsum, tricalcium aluminate hydration is renewed. Sodium sulfate does not significantly retard this hydration. The results confirm the hypothesis that ettringite formation is essential for coating 3CaO·Al2O3 grains and then retarding their hydration.

Giorgio Baldini

Papers

Tricalcium aluminate hydration in the presence of lime, gypsum or sodium sulfate

Combined effect of lignosulfonate and carbonate on pure portland clinker compounds hydration. I. Tetracalcium aluminoferrite hydration

Retardation of Tricalcium Aluminate Hydration by Calcium Sulfate

The effect of pozzolanas on the tricalcium aluminate hydration

A reply to S. Chatterji's discussion on “tricalcium aluminate hydration in the presence of lime gypsum or sodium sulfate”