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R. Talero - One of the best experts on this subject based on the ideXlab platform.
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synergic effect of friedel s salt from Pozzolan and from opc co precipitating in a chloride solution
Construction and Building Materials, 2012Co-Authors: R. TaleroAbstract:Abstract Two prior papers on this subject have shown, with XRD and SEM techniques, that almost all Pozzolanic additions can induce the rapid formation of Friedel’s salt in quantities in keeping with the reactive alumina, Al 2 O 3 r - (tetra- or penta-coordinated alumina) content of the Pozzolan. The formation rate of Friedel’s salt of Pozzolan origin has also been shown to be higher than the rate in the slower forming compound, whose origin is the C 3 A in OPC. Consequently, the plate-like hexagonal crystals are smaller and less perfectly shaped in fast- than in slow-forming Friedel’s salt. To describe the inter-relationships between these two non-expansive processes, a terminological analogy is drawn between the rapid and slow formation of Friedel’s salt and drug interaction. A common development in the treatment of certain diseases, drug interaction may be quantitative or qualitative and, depending on the end result, is typed under one of the following headings: additive synergy , partial antagonism , competitive antagonism , potentiating synergy , non-competitive antagonism or physiological and functional antagonism . Borrowing from this classification, the present study sought to determine whether the joint formation of Friedel’s salt from Pozzolan and from OPC in a common chloride solution is synergic , additive, antagonistic or able to invert the expected outcome. To this end, 14 binders, 2 PC (1 OPC and 1 SRPC) and 12 blended cements containing 20% or 30% of one of six Pozzolans, were analysed with XRD technique. Water resistance, capillary absorption and total porosity were also determined, along with the chemical composition and physical properties of some cement tested. The experimental results showed that fast- and slow-forming Friedel’s salt precipitated in a common chloride solution not separately but inter-dependently and the closer the Pozzolan particles were to the cement particles, the greater was that inter-dependence. Moreover, the joint precipitation – co-precipitation – of the Friedel’s salt from the Al 2 O 3 r - present in Pozzolans and the Friedel’s salt from the C 3 A present in OPC was, to use drug interaction terminology, consistently more synergic than additive . Furthermore, depending on the parameter considered and from a purely technological point of view, the practical implications of the Synergic Effect (SE) between the two types of Friedel’s salt were always beneficial. The experimental results showed, in addition, that the Pozzolanic activity of three of the Pozzolans tested, C, M1 and M0 specially, once again proved to be more specific than generic in chloride and water environments. This would induce speedier chloride hydration of all or part of the C 3 A in the OPC fraction than when the OPC was hydrated without the Pozzolan. Moreover, the Friedel’s salt from the Al 2 O 3 r - in these Pozzolans was the chief direct and indirect cause of the SE , in conjunction with the Friedel’s salt from the C 3 A in PC, due to their very specific Pozzolanic activity in such chloride media. In contrast, when the Pozzolan used was silica fume (SF), its Pozzolanic activity is not also more specific than generic for the same result but for the contrary result, that is, SF is unspecific for the same result.
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comparative and semi quantitative xrd analysis of friedel s salt originating from Pozzolan and portland cement
Construction and Building Materials, 2011Co-Authors: R. Talero, Viviana Fátima Rahhal, Lidia Natalia Trusilewicz, A Delgado, C Pedrajas, R Lannegrand, Raul Mejia, Silvio Delvasto, F A RamirezAbstract:Abstract The Friedel’s salt (Fs) is often formed when reinforced concrete is attacked by chlorides from marine environmental and/or thaw salts. In this investigation, a semi-quantitative analysis and study of the Fs (2θ range = 11.16–11.34°) in the solid phase of the Frattini test was made by XRD analysis. For this purpose, two Portland cements (PC) P1 (14% C3A) and PY6 ( 1. All the Pozzolans exhibited different Pozzolanic activity depending on the mineralogical composition of the Portland cement with which they were tested, although such differences were attributable more to their Al 2 O 3 r - (%) content than to their SiO 2 r - (%) content for the case of the Pozzolans A, C, M1 and M0 specially. Thus, M0, M1, C and A Pozzolans mainly, tend to sustain [OH−] content and react readily with Ca2+. On the contrary, for the SF and D Pozzolans was due to their SiO 2 r - (%) content only, which react with both, Ca2+ and OH− ions, in the same way. But despite what the physical state of D Pozzolan is like SF, vitreous mainly and its SiO 2 r - content as well (practically), the size and shape of their respective particles (“frustules” for D, empty, perforated sheaths) are totally different, and as a consequence, their respective behaviour in the Frattini test has been different as well. 2. In this investigation, the Friedel’s salt (Fs) owns its formation to two different origins: the C3A of PC and to the reactive alumina, Al 2 O 3 r - , of Pozzolans which reaction with chloride ions, pointing the latter as a preferential (see point 3); but it is also possible C4AF reactivity involved at later ages. 3. The role of the reactive alumina, Al 2 O 3 r - , and reactive silica, SiO 2 r - , (vitreous and/or amorphous fractions of the Pozzolanic additions) during the Friedel’s salt formation has been specified and, as a result, the formation rate of Fs from Al 2 O 3 r - of Pozzolan turns out to be notably higher than the formation rate of Fs from C3A of PC. For this reason, both have been termed rapid forming Fs or Fs-rf and slow forming Fs or Fs-lf, respectively, but in any case, topochemical mechanism with prior dissolution must be preponderant over through-solution mechanism. 4. The Friedel’s salt formation in all the PC/Pozzolan blends have coincided quantitatively in the vast majority of the cases with the respective reactive alumina, Al 2 O 3 r - (%), content of each Pozzolan. The number of these coincidences was greater for the PY6 blends, due to its C3A practical absence in these samples, since its presence in the P1 blends can stimulate directly, non-directly, but above all, indirectly the chemical reaction of the C3A hydration with NaCl solutions (3.75% and 3.00% in this study) and influence like that in the velocity of the compound formation: Fs. 5. The physical state of the reactive alumina, Al 2 O 3 r - , in C natural Pozzolan must be more amorphous than vitreous, resembling metakaolin more than fly ash. That notwithstanding, Pozzolan composition must have conditioned the water/cementitious material ratios obtained for their respective P1 and PY6 blended cements (a finding that could be used in the future for speedy, easy, reliable, reproducible and inexpensive characterization of natural and artificial Pozzolans, and logically for this purpose, its previous physics-chemical analysis, Frattini test at 2 and/or 7 and/or 28 days-age and/or mechanical strengths will also be previously needed), as well as its specific Pozzolanic activity.
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Fast physics-chemical and calorimetric characterization of natural Pozzolans and other aspects
Journal of Thermal Analysis and Calorimetry, 2009Co-Authors: Viviana Fátima Rahhal, R. TaleroAbstract:This research reports on the effects of including natural Pozzolans in two Portland cements with different mineralogical compositions, with and without excess gypsum at amounts equivalent to 7.0% SO3. The main analytical techniques used to study these effects were: the amount of water needed to make a paste of normal consistency, the 2-day Frattini Pozzolanicity test and conduction calorimetry. The results obtained showed that these natural Pozzolans caused contradictory (accelerating and retarding) effects on the rheology of the resulting cements, depending on the mineralogical composition of the respective Portland clinkers as well as the reactive chemical composition of the Pozzolans, in particular their reactive alumina content (Al2O3r−). The addition of gypsum also caused acceleration and delays in the calorimetric evolution of the resulting pastes, which proved to be heavily dependent upon the more or less aluminic chemical character of the natural Pozzolans studied. This, in turn, was conditioned by the higher or lower Al2O3r− content (for the SiO2r− content was of a very similar order of magnitude in all three Pozzolans analyzed). The Al2O3r− content was likewise responsible for paste behaviour in the afore-mentioned trials and analyses, and the Pozzolanic activity exhibited by the compound was found to be more specific than generic, indirectly stimulating C3A hydration more intensely and rapidly than C3S hydration in PC1, one of the two Portland cements used. Indeed, when these natural Pozzolans exhibited such prior Pozzolanic activity in the second cement studied, PC2, the hydration of its 79.5% of C3S was not indirectly stimulated to the same degree; rather, the contrary effect was observed, i.e., this cement was physically diluted by the three Pozzolans. Pozzolan O stimulated hydration directly and non-directly more than indirectly, while Pozzolan C acted conversely, and A exhibited varying combinations of the two patterns. The physical state of the reactive alumina, Al2O3r−, in these three natural Pozzolans, must be more amorphous than vitreous, i.e., resembling metakaolin more than fly ash in this regard. That notwithstanding, the reactive alumina content in each Pozzolan must have conditioned the water/cementitious material ratio obtained for the respective blends with both types of Portland cement (a finding that could be used in future for speedy, simple, reliable and economical characterization), as well as their specific Pozzolanicity developed and the rate and total heat of hydration generated by such blended cements.
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CALORIMETRY OF PORTLAND CEMENT WITH METAKAOLINS, QUARTZ AND GYPSUM ADDITIONS
Journal of Thermal Analysis and Calorimetry, 2008Co-Authors: Viviana Fátima Rahhal, R. TaleroAbstract:In this work two aluminic Pozzolans (metakaolins) and a non-Pozzolan were added to two Portland cements with very different mineral composition, to determine the effect on the rate of heat release and the mechanisms involved. The main analytical techniques deployed were: conduction calorimetry, Pozzolanicity and XRD.
Caijun Shi - One of the best experts on this subject based on the ideXlab platform.
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An overview on the activation of reactivity of natural Pozzolans
Canadian Journal of Civil Engineering, 2001Co-Authors: Caijun ShiAbstract:Natural Pozzolan is one of the oldest construction materials. Lime-Pozzolan cements have been used for several thousands of years and have an excellent reputation for their durability. Pozzolans are being widely used as a cement replacement in Portland cement concrete. The use of Pozzolans has the advantage of lower costs and better durability, but the disadvantage of a longer setting time and a slower early strength development. Different techniques have been tried to increase the reactivity of natural Pozzolans to overcome these disadvantages. This paper has reviewed various methods used to activate the Pozzolanic activity of natural Pozzolans. All activation methods can be classified into three catalogues: thermal, mechanical, and chemical activation. A comparison based on strengthcost relationship indicates that the chemical activation method is the most effective and cheapest one.Key words: activation, reactivity, natural Pozzolans, Pozzolanic reaction, calcination, elevated temperature curing, chem...
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Comparison of different methods for enhancing reactivity of Pozzolans
Cement and Concrete Research, 2001Co-Authors: Caijun Shi, Robert L. DayAbstract:Abstract This paper compares three methods for the activation of Pozzolanic reactivity of a natural Pozzolan: (1) prolonged grinding of natural Pozzolans (mechanical method), (2) elevated temperature curing of cement pastes containing a Pozzolan (thermal method), and (3) use of chemical activators such as Na2SO4 and CaCl2 (chemical method). The Pozzolanic reactivity of natural Pozzolans was evaluated using a mixture of 80% natural Pozzolan and 20% hydrated lime. Several parameters such as Ca(OH)2 consumption rate, strength development, ultimate compressive strength and cost were compared. All three activation methods accelerated both the Pozzolanic reaction and strength development rates of the lime–Pozzolan pastes. However, mechanical activation did not show a significant effect on the ultimate strength, while thermal activation decreased the ultimate strength and chemical activation (addition of 4% Na2SO4 or CaCl2·2H2O based on the mass of lime–Pozzolan blends) increased the ultimate strength of lime–Pozzolan mixtures significantly. The application of mechanical or thermal activation techniques needs extra equipment and energy, and thus increases materials costs significantly. Chemical activators can be added during the grinding of the natural Pozzolan or during the mixing of concrete containing a Pozzolan, so the requirement of extra equipment is minimal. Although the addition of chemical activator(s) increases the total material costs, the cost per unit strength development decreases. Based on current test results, chemical activation is the most efficient and feasible method for the activation of natural Pozzolans.
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Influence of the fineness of Pozzolan on the strength of lime natural-Pozzolan cement pastes
Cement and Concrete Research, 1994Co-Authors: Robert L. Day, Caijun ShiAbstract:Abstract The fineness of a cement is an important factor affecting the rate of strength development. This paper examines the importance of the fineness of natural Pozzolans to the strength development of lime-Pozzolan cements (LPCs). A natural Pozzolan from Bolivia, which is typical of natural Pozzolans found in South and Central America, was ground to various finenesses, blended with lime with a mass ratio of 80:20, and the resulting LPC was used to make hardened cement paste cylinders. In some pastes 4% sodium sulphate or 4% sodium chloride activator was used to enhance strength development. Strength of the cylinders were measured at ages from 3 to 90 days during continuous moist curing at 50°C. The experimental results show that there is a good linear correlation between the Blaine fineness of the natural Pozzolan and compressive strength at all ages and for all pastes. The fineness of the natural Pozzolan has its most significant effect on early strength gain. The addition of chemical activator increases both the rate of strength gain and the sensitivity of strength gain to fineness.
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Effect of initial water curing on the hydration of cements containing natural Pozzolan
Cement and Concrete Research, 1994Co-Authors: Robert L. Day, Caijun ShiAbstract:Abstract This paper deals with the effect of initial curing conditions on the hydration process of Portland Pozzolan cements. Experiments were performed on pastes made with Canadian Standards Association (CSA) Type 10 (ASTM Type I) Portland cement (PC) and Portland Pozzolan cement (PPC) containing 30% natural Pozzolan by mass. PC pastes are more sensitive than PPC pastes to the period of initial water curing because the hydration of PC occurs more quickly than does the Pozzolanic reaction in PPC pastes. The hydration of Portland cement and the Pozzolanic reaction continue after specimens are removed to a dry environment (relative humidity ≈ 20%). The presence of natural Pozzolans retards the normal hydration of PC before an age of 1 day but accelerates it after 1 day. For the tests reported here, an excellent correlation exists between strength and the quantity of “hydrate” water. The measurement of pore structure shows that the measurable total pore volume is significantly decreased for specimens that are water-cured and then dried, compared with those that are water-cured only. The period of initial water curing does not have a significant effect on total pore volume at 28 days (measured by Hg porosimetry), but does affect the pore size distribution. Examination of strength is not a good indicator of the effect of initial water curing.
Eleni Aggelakopoulou - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Pozzolanic activity of natural and artificial Pozzolans by thermal analysis
Thermochimica Acta, 2004Co-Authors: A Moropoulou, A Bakolas, Eleni AggelakopoulouAbstract:Abstract In this research, the Pozzolanic activity of natural and artificial Pozzolan used for preparation of restoration mortars was evaluated. For this purpose, several pastes were prepared, by mixing two artificial Pozzolans and a natural one with commercial hydrated lime, in different ratios. The pastes were cured in standard conditions (RH = 98%, T = 25 °C). The Pozzolanic activity was evaluated by using simultaneous differential thermal and thermogravimetric analysis (DTA/TG) after curing for 3, 7, 14, 28 days. The obtained results revealed that the various lime/Pozzolan pastes displayed different reaction kinetics and therefore the various Pozzolans present different reactivity, in proportion to its mineralogical, physical and chemical characteristics.
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Evaluation of Pozzolanic activity of natural and artificial Pozzolans by thermal analysis
Thermochimica Acta, 2004Co-Authors: A Moropoulou, A Bakolas, Eleni AggelakopoulouAbstract:In this research, the Pozzolanic activity of natural and artificial Pozzolan used for preparation of restoration mortars was evaluated. For this purpose, several pastes were prepared, by mixing two artificial Pozzolans and a natural one with commercial hydrated lime, in different ratios. The pastes were cured in standard conditions (RH = 98%, T = 25degreesC). The Pozzolanic activity was evaluated by using simultaneous differential thermal and then nogravimetric analysis (DTA/TG) after curing for 3, 7, 14, 28 days. The obtained results revealed that the various lime/Pozzolan pastes displayed different reaction kinetics and therefore the various Pozzolans present different reactivity, in proportion to its mineralogical, physical and chemical characteristics. (C) 2004 Elsevier B.V. All rights reserved
Ali Akbar Ramezanianpour - One of the best experts on this subject based on the ideXlab platform.
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Effect of type, form, and dosage of activators on strength of alkali-activated natural Pozzolans
Cement and Concrete Composites, 2011Co-Authors: Dali Bondar, Cyril J. Lynsdale, Neil B. Milestone, Nemat Hassani, Ali Akbar RamezanianpourAbstract:Abstract It is possible to synthesize environmentally friendly cementitious construction materials from alkali-activated natural Pozzolans. The effect of the alkaline medium on the strength of alkali-activated natural Pozzolans has been investigated and characterised. This paper highlights the effect of the type and form of the alkaline activator, the dosage of alkali and the SiO2/Na2O ratio (silica modulus, Ms) when using water–glass solutions and different curing conditions on the geopolymerisation of natural Pozzolans. Activation of natural and calcined Pozzolan for production of geopolymeric binder was verified by using Taftan andesite and Shahindej dacite from Iran as a solid precursor. The optimum range for each factor is suggested based on the different effects they have on compressive strength. The concentration of dissolving silicon, aluminium and calcium in alkaline solution, the formation of gel phase and the factors affecting this have been studied by using leaching tests, ICP–AES, and FTIR.
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Effect of heat treatment on reactivity-strength of alkali-activated natural Pozzolans
Construction and Building Materials, 2011Co-Authors: Dali Bondar, Cyril J. Lynsdale, Neil B. Milestone, Nemat Hassani, Ali Akbar RamezanianpourAbstract:Abstract Natural Pozzolans can be activated and condensed with sodium silicate in an alkaline environment to synthesize high performance cementitious construction materials with low environmental impact. The nature of the starting materials including mineral composition, chemical composition and crystal structure groups affects the formation of the geopolymer gel phase. In this paper, the Pozzolanic activities of five natural Pozzolans are studied. From XRD and XRF results, most of the raw materials contain zeolite clay minerals and have a high loss on ignition. Therefore, before use, samples were calcined at 700, 800 and 900 °C, respectively. The improvement in Pozzolanic properties was studied following heat treatment including calcinations and/or elevated curing temperature by using alkali solubility and compressive strength tests. The results show that Pozzolan containing sodium zeolite clinoptilolite can be used to prepare a moderate to high strength binder by heat treatment and calcinations can impart disorder hornblende as a constituent of Pozzolan with no amorphous phase to prepare a moderate strength binder.
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Engineering Properties of Alkali-Activated Natural Pozzolan Concrete
ACI Materials Journal, 2011Co-Authors: Dali Bondar, Cyril J. Lynsdale, Neil B. Milestone, Nemat Hassani, Ali Akbar RamezanianpourAbstract:The development of alkali-activated binders with superior engineering properties and longer durability has emerged as an alternative to ordinary portland cement (OPC). It is possible to use alkali-activated natural Pozzolans to prepare environmentally friendly geopolymer cement leading to the concept of sustainable development. This paper presents a summary of an experimental work that was conducted to determine mechanical strength, modulus of elasticity, ultrasonic pulse velocity, and shrinkage of different concrete mixtures prepared with alkali-activated Iranian natural Pozzolans—namely Taftan andesite and Shahindej dacite, both with and without calcining. Test data were used for Taftan Pozzolan to identify the effects of water-binder ratios (w/b) and curing conditions on the properties of the geopolymer concrete, whereas the influence of material composition was studied by activating Shahindej Pozzolan both in the natural and calcined states. The results show that alkali-activated natural Pozzolan (AANP) concretes develop moderate-to-high mechanical strength with a high modulus of elasticity and a shrinkage much lower than with OPC.
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Effect of adding mineral additives to alkali-activated natural Pozzolan paste
Construction and Building Materials, 2011Co-Authors: Dali Bondar, Cyril J. Lynsdale, Neil B. Milestone, Nemat Hassani, Ali Akbar RamezanianpourAbstract:Natural Pozzolans are raw materials from geological deposits with a range of chemical compositions that when combined with suitable alkali activators can be converted to geopolymer cement for concrete production. In this paper the concept of adding mineral additives to enhance the properties of geopolymer cement is introduced. Taftan andesite, a natural Iranian Pozzolan, was used to study the effect of adding mineral additives such as kaolinite, lime and other calcined Pozzolans on the compressive strength of geopolymer cement under both normal and autoclave curing. Scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) was used to determine the composition of the gel phase in both alkali-activated Taftan Pozzolan with and without mineral additions. The work has shown that deficiencies in SiO2, Al2O3 and CaO content in the raw natural Pozzolan can be compensated for by adding mineral additives for enhanced properties.
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Effect of Four Iranian Natural Pozzolans on Concrete Durability against Chloride Penetration and Sulfate Attack
2010Co-Authors: Ali Akbar Ramezanianpour, E. Aramun, M. Peidayesh, Peter A. Claisse, E Ganjian, F CanpolatAbstract:Sulfate attacks and chloride corrosion are the most important problems concerning the durability of concrete structures in hot regions of the Persian Gulf and Oman Sea. Natural Pozzolans are natural mineral admixtures which can improve concrete durability against sulfate attacks and chloride corrosion. This paper presents the results of experimental study on the effect of natural Pozzolans: Jajrood Truss, Eskandan Pumice, Abyek Tuff, and Khash Pumice, on the ordinary structural concrete durability. Concrete specimens were made of three Pozzolan replacement levels, and Rapid Chloride Penetration test, Electrical Resistance test, and Half Cell Potential test were conducted at different ages. In addition, strength reductions and mass changes of concrete specimens immersed in sodium sulfate solution and expansion of concrete prisms immersed in sodium sulfate solution and magnesium sulfate solution were studied. Generally, the results indicate that natural Pozzolans have positive effects on concrete specimen resistance to the chloride ions penetration and bars corrosion in comparison with concretes containing ordinary cement.
María Victoria Borrachero - One of the best experts on this subject based on the ideXlab platform.
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new method to assess the Pozzolanic reactivity of mineral admixtures by means of ph and electrical conductivity measurements in lime Pozzolan suspensions
Materiales De Construccion, 2014Co-Authors: M M Tashima, María Victoria Borrachero, José Monzó, L Soriano, Jorge Luis Akasaki, J PayaAbstract:A very simple method based on electrical conductivity and pH measurements was proposed for assessing reactivity of Pozzolans. Calcium hydroxide:Pozzolan water suspensions were monitored by means of measurements of electrical conductivity and pH values. In these suspensions, Ca(OH)2 in solid state was initially present, being them, thus, saturated in this reagent. Three testing temperatures were selected (40, 50 and 60 °C). In the experiments carried out, calcium hydroxide was suspended in deionized water for yielding a lime saturated suspension. The addition of siliceous Pozzolan (two types of rice husk ash RHA and two types of densified silica fume DSF were tested) to the saturated lime suspension can produce the unsaturation of the system, depending on the testing time, testing temperature and reactivity of Pozzolan. When unsaturation was reached, the loss of electrical conductivity was higher than 30% and the variation of pH was higher than 0.15 units. These threshold values were selected for characterizing the reactivity of Pozzolans by means of a proposed template, classifying the Pozzolan in three different reactivity levels.
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Assessment of Pozzolanic Activity Using Methods Based on the Measurement of Electrical Conductivity of Suspensions of Portland Cement and Pozzolan.
Materials (Basel Switzerland), 2014Co-Authors: Sergio Velázquez, José Monzó, María Victoria Borrachero, Jordi PayáAbstract:The use of methods based on measuring electrical conductivity to assess Pozzolanic activity has recently been used primarily in aqueous suspensions of Pozzolan: calcium hydroxide. However, the use of similar methods in suspensions of cement with Pozzolans has not been widely studied. This paper proposes a new method for rapid assessment of the Pozzolanic activity of mineral admixtures in aqueous cement suspensions. In this study, the conditions for the application of the method were optimized, such as time, temperature, w/c ratio and dosage procedure. Finally, results are presented from the application of this method for characterizing the Pozzolanic activity of the spent catalytic cracking catalyst. These results corroborate as previously reported, namely the high reactivity of this Pozzolan obtained by other methods, such as thermogravimetry or evolution of the mechanical strength. In addition, the Pozzolanic activity of the catalyst was compared with other Pozzolans such as metakaolin and silica fume.
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effect of Pozzolans on the hydration process of portland cement cured at low temperatures
Cement & Concrete Composites, 2013Co-Authors: L Soriano, José Monzó, M M Tashima, J Paya, M Bonilla, María Victoria BorracheroAbstract:Abstract The aim of this paper is to study hydration processes in cement pastes and mortars, blended with either metakaolin (MK) or a catalyst used in catalytic cracking (FCC), and cured at low temperature. The amounts of hydrates and portlandite in pastes have been determined for 3–28 days curing at 5–20 °C. Microstructural study, using thermogravimetric analysis of the pastes, has shown that FCC acts mainly as a Pozzolan at low temperatures (5–10 °C), whereas MK also accelerates Portland cement hydration. Mechanical strengths of a control mortar, and mortars made with 15% replacement of cement by these two Pozzolans, have been measured. Both mortars containing Pozzolans exhibited a relative increase in compressive strength when cured at 5 °C. A limestone filler (LF) has been used to compare the effects of adding inert or Pozzolanic materials. Finally, mortars were prepared by partially replacing aggregates with either MK, FCC or LF. The MK and FCC are effective materials even for low curing temperatures, especially when they are used to replace a fraction of the aggregates in mortars.
