Natural cement as the precursor of Portland cement: Methodology for its identification

Varas, María José; Buergo, Mónica Álvarez de; Fort, Rafael

doi:10.1016/j.cemconres.2004.10.045

Cited by 77 publications

(41 citation statements)

References 4 publications

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“…This band decreased in size as the curing time was extended in the spectra of FA10, SF10 and specifically in the FTIR spectrum of NS10 after 28 days reminding lesser extent of ettringite formation in NS10 [44,46,47] . The strong band observed at 949 cm -1 and the band observed at 719 cm -1 were associated with the bending-in-plane vibrations of the Si-O bonds in tricalcium silicates (C 3 S) and dicalcium silicates (C 2 S) [1,40,42,47] . The intensity of these bending-in-plane vibrations of the Si-O Figure 5.…”

Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

“…The broad bands appearing at 3648-3650 cm -1 in the spectra of all mortar specimens including OPC (control) corresponded to the overlapping stretching vibrations of the structural -OH groups (ν 3 ) of Ca(OH) 2 formed during the hydration of C 3 S and C 2 S, and the free -OH groups (ν 1 ) of water molecules present in the mixture 41,42 . This band diminished for all samples as the hydration process proceeded, implying a decrease in free water due to C-S-H bond formation 43 .…”

Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

“…This band shifted slightly to 3410-3390 cm -1 and became broader and smaller in the IR spectra of the NS10 and SF10 specimens. This phenomenon indicated a decrease in the amount of bonded -OH groups and free water, signifying reduction in Ca(OH) 2 content, and increase in C-S-H content in NS10 and SF10 [1,[41][42][43][44] . The bending-in-plane vibrations of the -OH groups (ν 2 ) of free water molecules are characterized by a small broad band at 1671 cm -1 .…”

Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

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Comparative study of the characteristics of nano silica - , silica fume - and fly ash - incorporated cement mortars

2014

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The structural characteristics of cement mortars, impregnated with nano silica (NS), silica fume (SF) and fly ash (FA), were comparatively studied using Fourier transform infrared spectrometer (FTIR), thermogravimeter-differential thermogravimeter (TG-DTG) and scanning electron microscope (SEM). The mechanical strengths of the specimens were determined at early (7th day) and standard (28th day) curing ages. The compressive strengths and flexural strengths developed in the mortar specimens containing NS particles were found considerably higher than those of the corresponding specimens of SF and FA over and above the control at both ages. FTIR, TG-DTG and SEM analyses results were consistent with the remarkable increase in the mechanical strength of the mortars with NS. These increases in the strengths of the mortars with NS are attributable to the nano sized particles and extensive surface area of NS. The nano sized particles, as nucleating agents, promoted the hydration of C 3 S and C 2 S and the formation of C-S-H phase. Plenty of active sites on the surface of NS particles induced their pozzolanic reactivity and the extent of bond formation between NS particles and free CH.

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Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

Section: Characterization Of the Mortar Specimensmentioning

confidence: 99%

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Comparative study of the characteristics of nano silica - , silica fume - and fly ash - incorporated cement mortars

2014

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“…Recent studies have been also focused on characterisation of some XIX and XX century mortars. Methodologies have been defined in order to identify the nature of binders and to distinguish between natural hydraulic mortars, natural cements and Portland cements [4,5]. FTIR, XRD analysis and SEM observation have been employed to identify gehlenite and C 3 S, as characteristic hydraulic phase respectively of natural hydraulic lime and cements.…”

Section: Introductionmentioning

confidence: 99%

Investigation of commercial ready-mixed mortars for architectural heritage

Gulotta¹,

Toniolo²,

Binda³

et al. 2009

WIT Transactions on the Built Environment

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In conservation practice, operations aiming to restore structural functionality of historical buildings are of primary relevance. Partial rebuilding, the substitution of damaged bricks or blocks and the integration of deteriorated joints are, among others, interventions that require the introduction of new materials in a heterogeneous and aged masonry system. An appropriate durability of these interventions can only be assured if a deep knowledge of the original materials and of their state of conservation is combined with reliable understanding of the behaviour of new materials introduced. The present paper reports the results of the investigation of four commercial ready-mixed mortars based on NHL binders. The mineralogical composition of each product has been evaluated by XRD and polarization-and-fluorescence microscopy (PFM). The molecular composition of the mixes has also been evaluated by FTIR spectroscopy and the morphological features have been studied by SEM observations. The mechanical behaviour has been tested as well. Although supposedly comparable products, the mortars show different compositional features, microstructures, additives and mechanical behaviour. These are essential to evaluate compatibility with historic materials, and should be stated on the technical data sheets, or be determined.

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“…The broad band detected at 3711 cm -1 in the infrared spectroscopy of OPC linked to overlap stretching vibrations of both the structural and free hydroxy groups of CH and water respectively. FTIR spectra of RC, CA, FA20CA which have been defined as fingerprint evidence for the degree of polymerization with the formation of calcium-silicate-hydroxide phase due to hydration [24] having strong band observed at 900 cm -1 and the band observed at 520 cm -1 were associated with the bending-in-plane vibrations of the Si-O bonds in C3S (tricalcium silicates) and C2S (dicalcium silicates) [25][26][27][28]. The intensity of these bending-in-plane vibrations of the Si-O bonds decreased as calcium-silicate-hydroxide crystals formed [24,29].…”

Section: Microstructural Analysismentioning

confidence: 99%

Self-Healing Ability of High-Strength Fibre-Reinforced Concrete with Fly Ash and Crystalline Admixture

Reddy

Theja²,

Sashidhar

2018

CivileJournal

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The aim of this study is to analyse the self-healing capability of high-strength fibre-reinforced concrete (M70) with fly ash and crystalline admixture (CA) in four types of environmental exposures i.e. Water Immersion (WI), Wet-Dry Cycles (WD), Water contact (WC) and Air Exposure (AE). Specimens for four mixes are cast, one mix containing 1.1% of CA and three mixes with 10%, 20% and 30% partial replacement of cement with fly ash and additions of 1.1% CA. The specimens were pre-cracked at 28 days, in the range of 0.10-0.40 mm and the time set for healing was 42 days. The result shows that all the mixes have considerable amount of closing ability and strength-regaining capability for all exposure conditions. The concrete with 20% fly ash and 1.1% CA has complete crack closing ability and 100% strength-regaining capability for WI and WD cycle conditions. From SEM analysis, it is confirmed that self-healing products are CaCO3 and C-S-H gel.

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Natural cement as the precursor of Portland cement: Methodology for its identification

Cited by 77 publications

References 4 publications

Comparative study of the characteristics of nano silica - , silica fume - and fly ash - incorporated cement mortars

Comparative study of the characteristics of nano silica - , silica fume - and fly ash - incorporated cement mortars

Investigation of commercial ready-mixed mortars for architectural heritage

Self-Healing Ability of High-Strength Fibre-Reinforced Concrete with Fly Ash and Crystalline Admixture

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