Optical and Electronic Microscope for Minero-Petrographic and Microchemical Studies of Lime Binders of Ancient Mortars

In this paper, the advances in the use of optical and electronic microscope for study of the minero-petrographic and microchemical features of lime binders of ancient mortars are discussed for various case studies. Mortars belonging to several historic periods and with different functions in building structures and archaeological sites were selected in order to verify the complementarity of optical and electronic microscope analyses applied to these artificial materials. The data obtained with the application of optical and microscope analyses were able to provide detailed and more precise information on the composition, structure, and texture of lime binders, highlighting the features of air hardening calcitic lime binder, air hardening magnesian lime binder, natural hydraulic lime binder, and air hardening binders with materials providing hydraulic characteristics added. Furthermore, a complete analysis and classification of the lime lumps was determined.

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Mechanical and physical performance of natural hydraulic lime mortars

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123272 ◽

2021 ◽

Vol 290 ◽

pp. 123272

Author(s):

Maria Apostolopoulou ◽

Asterios Bakolas ◽

Meletis Kotsainas

Keyword(s):

Physical Performance ◽

Hydraulic Lime ◽

Natural Hydraulic Lime ◽

Lime Mortars ◽

Natural Hydraulic Lime Mortars

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Bond Properties of NHL-Based Mortars with Viscosity-Modifying Water-Retentive Admixtures

Minerals ◽

10.3390/min11070685 ◽

2021 ◽

Vol 11 (7) ◽

pp. 685

Author(s):

Tomáš Žižlavský ◽

Patrik Bayer ◽

Martin Vyšvařil

Keyword(s):

Water Content ◽

Adhesive Strength ◽

Water Retention ◽

Minor Role ◽

Clay Brick ◽

Hydraulic Lime ◽

Natural Hydraulic Lime ◽

Binder Ratio ◽

Paste Viscosity ◽

A Minor

This article studies the influence of biopolymeric viscosity-modifying admixtures with water-retentive function on the physico-mechanical properties of natural hydraulic lime-based mortars and their adherence to the traditional fired-clay brick substrate. The use of admixtures increases the water/binder ratio, which in turn leads to a decrease in the strength of the mortars. The viscosity-modifying function improves the adhesive strength between mortar and pre-wetter brick by increasing the binder paste viscosity, while the water-retentive function along with increased water content may lead to a decrease in adhesive strength. On the contrary, water retention and increased water content are beneficial on a dry surface, while paste viscosity plays only a minor role. When subjected to temperature-varying cycles, the mortars are more prone to in-mortar failure during the pull-off test. The air-entraining function of some admixtures improves the frost resistance of the mortars; however, it would negatively affect the adhesive strength by incorporating pores into the contact zone between the mortar and brick substrate. This study showed that the use of some of the studied admixtures may improve the adhesion of mortar to the brick substrate.

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Influence of Sample Thickness and Capping on Characterization of Bedding Mortars from Historic Masonries by Double Punch Test (DPT)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.624.322 ◽

2014 ◽

Vol 624 ◽

pp. 322-329 ◽

Cited By ~ 10

Author(s):

Enrico Sassoni ◽

Elisa Franzoni ◽

Claudio Mazzotti

Keyword(s):

Compressive Strength ◽

Poor Quality ◽

Sample Thickness ◽

Mortar Sample ◽

Hydraulic Lime ◽

Punch Test ◽

Natural Hydraulic Lime ◽

Wide Range ◽

Surface Capping

For determination of compressive strength of bedding mortar used in historic masonries, a promising moderately-destructive technique is double punch test (DPT). DPT consists of loading prismatic samples of mortar (about 4×4×1 cm3) by means of two circular steel platens (typically 2 cm diameter) and then calculating mortar compressive strength as the ratio of the failure load to the cross section of the circular platens. In this study, the influence of mortar sample thickness and mortar sample capping on the reliability of results obtained by DPT was systematically investigated. The influence of sample thickness was assessed by comparing DPT results obtained for samples with 5, 10, 15 and 20 mm thickness with compressive strength determined by testing reference 4 cm-side cubes. Different mortars were considered (cement, lime-cement, natural hydraulic lime), in order to investigate a wide range of mortar mechanical characteristics. The influence of surface capping was evaluated on a lime-cement mortar by comparing compressive strength determined on reference cubes with strength obtained by DPT on proper samples, without capping and after capping with rubber, gypsum and cement. The results of the study indicate that sample thickness substantially influences mortar compressive strength determined by DPT, which may vary by up to three times depending on sample thickness. A good estimation of the actual mortar compressive strength was obtained when samples with thickness similar to the loading platens diameter were tested, which suggests that choosing the size of the loading platens for DPT based on the thickness of mortar joints under investigation may be an effective way for obtaining reliable estimations. As for the influence of surface capping, in those cases where no mortar sample regularization is possible, because of the poor quality of the mortar, the results of the study indicate that sample capping actually seems necessary in order to avoid significant underestimations of mortar compressive strength. Considering the higher practicality offered by gypsum with respect to rapid-setting cement for surface capping, the use of gypsum seems preferable.

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CURRENT ASSETS OF THE ENTERPRISE: THEORETICAL AND PRACTICAL ASPECTS

Food Industry Economics ◽

10.15673/fie.v10i1.863 ◽

2018 ◽

Vol 10 (1) ◽

Cited By ~ 2

Author(s):

N. Kuprina ◽

I. Chernenko

Keyword(s):

Food Industry ◽

Working Capital ◽

Accounts Receivable ◽

Concepts And Categories ◽

Composition Structure ◽

The Relationship

In the article the concepts and categories of nature of the categories "current assets", "workingcapital", "current funds" have been examined and investigated the relationship between these categoriesand approaches to classification of current assets of enterprise that are presented in the publications ofdomestic and foreign scientists. The have been investigated analysis of composition, structure anddynamics of the working capital of an enterprise and its separate elements were made for four years,which is invested in its current assets based on the data of food industry enterprises of Odesa region.Estimation of the effect of turnover of enterprise working capital invested in accounts receivable andreserves on liquidity of current assets has been was made. The ways of increasing efficiency of currentassets use in PLC “Odesaconditer” were proposed.

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Natural hydraulic lime versus cement for blended lime mortars for restoration works

Construction and Building Materials ◽

10.1016/j.conbuildmat.2015.06.058 ◽

2015 ◽

Vol 94 ◽

pp. 346-360 ◽

Cited By ~ 49

Author(s):

B.A. Silva ◽

A.P. Ferreira Pinto ◽

A. Gomes

Keyword(s):

Hydraulic Lime ◽

Natural Hydraulic Lime ◽

Lime Mortars

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Design and evaluation of restoration mortars for historic masonry using traditional materials and production techniques

MRS Proceedings ◽

10.1557/proc-712-ii2.7 ◽

2002 ◽

Vol 712 ◽

Author(s):

Antonia Moropoulou ◽

Asterios Bakolas ◽

Petros Moundoulas ◽

Eleni Aggelakopoulou ◽

Sofia Anagnostopoulou

Keyword(s):

Mechanical Strength ◽

Water Absorption ◽

Mechanical Tests ◽

Hydraulic Lime ◽

Historic Masonry ◽

Natural Hydraulic Lime ◽

Total Percentage ◽

Lime Mortars ◽

Production Techniques ◽

Absorption Measurements

ABSTRACTCement based mortars used for historic masonry restoration presented unsatisfactory results, due to their chemical and physico-mechanical incompatibility to original buildings. In the present research, several syntheses of restoration mortars are produced using traditional techniques and materials such as binders (aerial and natural hydraulic lime), pozzolanicadditives (natural and artificial pozzolanas) and aggregates (sand and crushed brick). The technical characteristics of the mortars were determined using mechanical tests (compressive and flexural) and mercury intrusion porosimetry measurements at the time of 1, 3, 9, 15 months of curing. Water absorption measurements were performed at the time of 9 and 15 months curing, in order to evaluate mortars microstructural characteristics, their rate of water absorption and the total percentage of absorbed water. The aerial lime - artificial pozzolana mortar presented the best mechanical and microstructural performance. Hydraulic mortars acquired the maximum of the mechanical strength in 1 month, lime - pozzolana mortars in 3 months while aerial lime mortars continue to gain mechanical strength even in 15 months curing. Furthermore, the use of ceramic aggregates produces lightweight and elastic mortars, compatible to historicones.

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Shaking Table Tests on Multi-Leaf Stone Masonry Structures: Analysis of Stiffness Decay

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.133-134.647 ◽

2010 ◽

Vol 133-134 ◽

pp. 647-652 ◽

Cited By ~ 5

Author(s):

Nicola Mazzon ◽

Cano M. Chavez ◽

Maria Rosa Valluzzi ◽

F. Casarin ◽

Claudio Modena

Keyword(s):

Dynamic Behaviour ◽

Shaking Table ◽

Stone Masonry ◽

Mode Shapes ◽

Masonry Structures ◽

Shaking Table Tests ◽

Grout Injection ◽

Hydraulic Lime ◽

Natural Hydraulic Lime ◽

Before And After

The influence of the natural hydraulic lime-based grout on the dynamic behaviour of injected multi-leaf stone masonry elements is discussed in the paper. Shaking table experiments on two stone masonry buildings, tested before and after grout injection, have been performed. The paper focuses on the analysis of both the recorded accelerations and related displacements, at the bottom and at each further storey. This leads to evaluate the stiffness of the unstrengthened and injected structures. The input at increasing PGA allowed the stiffness decay to be studied, simulating a gradual damaging of the structures. These results were also interpreted in the light of both computed frequencies and mode shapes. Finally, the comparison among these results, obtained from all the models, allows to deepen the knowledge concerning the effects induced by the lime-based grout injection and on its capability to modify the dynamic behaviour, when intervening on a damaged (repairing) or on an undamaged (strengthening) structure.

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