Showing papers by "Francisca Puertas published in 2008"
TL;DR: In this article, the authors explored the reactivity and burnability of clinker made with fired red or white ceramic wall tile wastes and combinations of the two as alternative raw materials.
Abstract: The cement industry has for some time been seeking procedures that would effectively reduce the high energy and environmental costs of cement manufacture. One such procedure is the use of alternative materials as partial replacements for fuel, raw materials or even clinker. The present study explores the reactivity and burnability of cement raw mixes containing fired red or white ceramic wall tile wastes and combinations of the two as alternative raw materials. The results showed that the new raw mixes containing this kind of waste to be technically viable, and to have higher reactivity and burnability than a conventional mix, providing that the particle size of the waste used is lower than 90 μm. The mineralogical composition and distribution in the experimental clinker prepared were comparable to the properties of the clinker manufactured with conventional raw materials. Due to the presence of oxides such as ZnO, ZrO 2 and B 2 O 3 in tile glazing, the content of these oxides was higher in clinker made with such waste. The mix of red and white ceramic wall tile waste was found to perform equally or better than each type of waste separately, a promising indication that separation of the two would be unnecessary for the purpose described above.
210 citations
TL;DR: In this paper, a naphthalene derivative admixture was used in waterglass-activated slag pastes and mortars to reduce the yield stress of the saliency.
Abstract: The rheology of waterglass-(Na 2 O·nSiO 2 ·mH 2 O) and NaOH-activated slag pastes and mortars depends on the nature of the alkaline activator used: in waterglass-activated slag pastes and mortars, the extensive structural breakdown under shear makes the Herschel-Bulkley model a better fit to the down ramp of the flow curve, whereas NaOH-activated pastes and mortars, such as portland-cement pastes and mortars, behaved like Bingham fluids. Admixtures were unable to reduce the yield stress of waterglass-activated slag pastes, but the inclusion of a naphthalene derivative admixture in NaOH-activated slag pastes reduced the yield stress by 80%. The problem of undesirably short setting times for waterglass-activated slag mortars and concretes could be overcome by an extended mixing time, giving an initial set of nearly 3 hours.
155 citations
TL;DR: In this paper, the performance of concrete made with waterglass (Na 2 SiO 3 •nH 2 O + NaOH)-activated Colombian granulated blast furnace slag was compared to the properties of ordinary Portland cement concrete (OPC) with the same proportion of binder.
Abstract: This article reports the results of related to on the performance of concrete made with waterglass (Na 2 SiO 3 •nH 2 O + NaOH)-activated Colombian granulated blast furnace slag. The mechanical strength and durability properties this alkali-activated slag concrete (AAS) were compared to the properties of ordinary Portland cement concrete (OPC) with the same proportion of binder, which ranged from 340 to 512 kg per m 3 of concrete. The results indicated that increasing the proportion of slag led to improvements in the properties studied.
76 citations
TL;DR: In this paper, a number of techniques and methods were used to study hydration: compressive strength, thermogravimetric, X-ray diffraction, mercury intrusion porosimetry, backscattered electron imaging, and nuclear magnetic resonance (NMR).
58 citations
TL;DR: In this article, the effect of adding 0.5 and 2% ZnO, ZrO2 and B2O3 to the raw mix, separately and jointly, on clinkerization and the distribution and morphology of the mineral phases in the clinker was explored.
Abstract: The use of clay-based product waste as an alternative prime material in Portland cement raw mixes raises the ZnO, ZrO2 and B2O3 content in the clinker. These compounds are found in the enamelled surface of the tile added to the raw mix. The present study explores the effect of adding 0.5 and 2% ZnO, ZrO2 and B2O3 to the raw mix, separately and jointly, on clinkerization and the distribution and morphology of the mineral phases in the clinker. The findings showed that while ZnO and ZrO2 are fixed in the clinker, B2O3 is partially volatized. Zinc oxide acted as a flux, while neither ZrO2 nor B2O3 increased the molten phase. The addition of the oxides to the raw mix changed the content of the main mineral phases in the clinker. Zinc oxide lowered the C3S and C3A contents, ZrO2 reduced the ferritic phase and B2O3 stabilized C2S. New mineral phases, namely 3CaO·ZnO·2Al2O3 and CaZrO3, were identified in the clinkers obtained when 2% ZnO and ZrO2 were added to the raw mix.
3 citations
TL;DR: In this paper, a revision of the most influential scientifi c journals on building materials is presented, focusing on the evolution, actual situation and future perspectives of the journal "Materiales de Construccion".
Abstract: In this communication a revision of the most infl uence scientifi c journals on building materials will be presented. Special attention would be paid in historic evolution, actual situation and future perspectives of the journal "Materiales de Construccion". This journal is edited by CSIC and manages in the Eduardo Torroja Institute of Construction Science. The infl uence of its presence on the journal on Journal Citation Reports data base will be examined. Also more data about the presence of the journal on others data base and the origin the different papers will be presented.
1 citations