Search results for "Pozzolanic reaction"
showing 5 items of 5 documents
Effect of superplasticizers on the rheological properties of fly ash suspensions containing activators of the pozzolanic reaction
2000
Rheological studies have been carried out on the effect of a superplasticizer from the sulphonated melamine formaldehyde (SMF) group upon the properties of fly ash suspensions containing a small quantity of mineral admixtures such as cement, lime and gypsum. The superplasticizers' efficiency has appeared to depend greatly on the admixture used. The highest liquefaction degree was found in fly ash suspensions containing both cement and gypsum together and the next it was, when only cement was added. These suspensions exhibit features of a newtonian fluid of low plastic viscosity, when the water to solid ratio (w/s) is 0.3 and a superplasticizer has been used. However, fly ash suspensions wit…
Analysis of the chemical and microstructural modifications effects on the hydro-mechanical behaviour of a lime-treated clay
2019
The paper presents the results of a characterization of kinetic characteristics of pozzolanic reaction with the aim to investigate the time-dependent modification of clay properties as a consequence of mixing with lime. Results of chemical analyses are in agreement with the increase of mechanical properties and with the observed microstructure modifications up to one year of curing time. The rate of development of pozzolanic reactions seems to be almost constant while the time required for their completion is dependent on the lime content. Pozzolanic products are responsible for the time reduction of swelling strain upon saturation as well as for the increases of yielding stress, stiffness …
On the hydro-mechanical behaviour of a lime-treated embankment during wetting and drying cycles
2018
Abstract The paper presents some experimental results obtained on samples extracted from a full-scale embankment obtained by compacting a lime-treated clayey soil. A comprehensive test programme was carried out in order to highlight the improvement of mechanical behaviour induced by lime treatment as well as to assess the durability of the improved material, which may be affected by severe seasonal wetting and drying cycles. Direct shear tests, triaxial compression tests, swelling potential measurement and oedometric tests were performed on samples cured in controlled environmental conditions for at least 18 months. Wetting and drying cycles were applied in a very wide range of suction valu…
Effect of some additives on the reactions in fly ASH-Ca(OH)2system
2004
Differential thermal analysis and thermogravimetry were used to evaluate the effect of some additives, such as CaSO4, CaCl2 and silica fume amorphous silica from ferrosilicon synthesis on the mechanism and kinetics of reactions occurring in fly ash-Ca(OH)2 system. The accelerating role of these additives was demonstrated from the data relating to Ca(OH)2 consumption in hydrated pastes, determined by TG measurements.
Petro-archaeology of Gallo-Roman lime mortar. Attempt to reconstruction and interpretation of the “chaînes opératoires”: from material to ancient cra…
2003
Petro-archaeological research on Gallo-Roman lime mortars is based on a simple analytical methodology: observations with optical microscopy in transmission, which brings us a maximum of data about the material and the various stages of the “chaîne opératoire”. This work enabled us to draw the general features of the craftmanship (common practices of the ancient structores and tectores), to establish the relations between mortar composition and its “primary” and “secondary” architectural function, then to perceive what are the markers and motivations of the formula adaptations. The importance of the geological environment is shown, because it induces economic and technical choices, requiring…