44 research outputs found
Chalk putty: specimen preparation and aging properties
No full textChalk putty is a soil-like material that is formed when intact chalk is disturbed. Recently, it has become of special interest due to the development of offshore wind farms in the North and Baltic Seas, where in a number of sites piles are driven into chalk strata. Several pile tests reported in the literature show increased shaft capacity up to 4 months after driving. Although it is a widespread remark in the scientific publications that chalk properties improve over time, laboratory replications of this phenomenon are scarce and the results are inconclusive. The aim of this thesis is to develop a specimen preparation technique yielding representative specimens as well as feasible for commercial purposes. Thereafter, the evolution of the characteristics of chalk putty over time is assessed through laboratory tests. Triaxial with Bender Elements, Direct Simple Shear, Constant Rate of Strain and Thixotropy have been conducted on specimens aged up to 3 months. Finding that the behavior of chalk putty cannot be classified among the classic types of soils. On one hand, Constant Rate of Strain tests have shown that the response is comparable to silty soil, with a gradual transition between re-loading and virgin compression lines, leading to difficulty in the determination of the yield point. On the other hand, in shear, the critical state friction angle is in the range of dense sand. Regarding the volumetric response, there is an initial compressive response, succeeded by a constant volume phase during destructuration and eventual dilation or contraction at larger strains. Furthermore, it was determined that the material possesses thixotropic properties when mixed with de-ionized water. Finally, no increase in the shear strength or was recorded while the initial shear stiffness decreases with aging time -due to unconfined preservation of the samples. However, the ultimate dilatancy of the specimens increases over time, this may be a result of dissolved calcium carbonate during crushing and saturation which re-precipitates or re-cements around the grains.Applied Earth Science
On the Utilities of Putty and "Shippi" as Air-tight Materials in Woodenship Building
No full textThe author examined the strength of putty and "Shippi", which was locally used at Kushikino in Kagoshima prefecture, and proved that Shippi was superior in utility to putty as air-tight materials in wooden-ship building
The Effect of Mechanical Activation of Lime Putty on Properties of the Autoclaved Calcium Hydrosilicate Materials
No full textAbstractThe lime putty is a non-Newtonian fluid that can be either thixotropic or rheopectic depending on burning process of the lime, the presence of the quartz sand and other parameters. One of the most important lime putty characteristics is its plasticity which affects its workability and use. It is possible to increase the lime putty plasticity by mechanical activation. This work focuses on the effect of the mechanical activation of the lime putty on its rheological behavior and on properties of lime hydrosilicate autoclaved materials. Fresh lime putty was activated in a high-speed mixer at 1000 RPM for 1, 3, 5 and 10minutes. Non-activated lime putties show rheopectic behavior. Rheopectic behavior becomes slightly more distinct after 1min. of activation and then less distinct with increasing time of activation. After 10min. of activation, the system shows no time-dependent properties, nor even slight thixotropic behavior. This trend can be related to process where smaller and smaller aggregates are fragmented in the suspension. The hydrosilicate materials were prepared in two series from quicklime and finely ground sand with the ratio C/S 0.85, under hydrothermal conditions. The amount of xonotlite in hydrosilicate material increases with activation time as the increased amount of portlandite particles retards the reaction. 11.3 Å tobermorite crystallizes more slowly and formation of xonotlite is accelerated
The influence of slaking time on lime putty
No full textA new interest in the preservation of mortars, plasters and decorative finishings in façades has emerged in certain European countries in the past thirty to forty years, with a view to understanding how they have evolved throughout History. There is a growing interest in learning about the composition and execution techniques of original surfaces and a number of Heritage Institutions have encouraged the systematic application of conservation in this area.
Up to the XX century, limes were often used in work as lime putty. After the transformation of quicklime into lime putty the latter was stored to maintain its characteristics. Tanks or large pits were used to store the lime putty, always covered with water in order to prevent its carbonation. The quality of the material was guaranteed for many years with this process.
The evolution of the storage processes for materials has led to a change in this procedure and in most cases binders are now used as powders.
The influence of the maturation time of lime putty has been studied. The aim of this paper is to present the physical and microstructural changes on lime putty due to the effect of ageing, focusing on the particle size of the portlandite crystals and on the reorganization of the internal structure.The authors thankfully acknowledge the support of the National Laboratory of Civil Engineering, in Lisbon, where the experimental work presented here was performed, of the ICIST Research Institute from IST, Technical University of Lisbon and of the Interface Analysis Centre, University of Bristol. They also thank the support of the Portuguese Foundation for Science and Technology (FCT) which partially financed this research, within Research Project PTDC/ECM/100234/2008 - Conservation and durability of historical renders: compatible techniques and materials and of the Portuguese Foundation Calouste Gulbenkian that supported the PhD scholarship of the first author.213697-704 ppDM/NMM201112 a 15 de Abri
MANURE BMP ADOPTION AMONG NORTH DAKOTA ANIMAL FEED OPERATIONS
Full text linkRegulations governing animal waste storage are primarily a state-level issue. Protecting water resources from animal waste contamination will depend upon how effective state-level animal waste regulations are in encouraging livestock producers to handle waste appropriately. Survey results from North Dakota indicate beef cattle feeding operations do not always comply with state regulations requiring adoption of manure storage BMP's. This is most likely due to incomplete inspection schedules by the regulatory agency. Statistical results suggest herd size plays a much larger role than regulation in promoting adoption of manure storage BMP's.Livestock Production/Industries,
パテ及びしっぴの効用比較に就て(予報)
No full textThe author examined the strength of putty and "Shippi", which was locally used at Kushikino in Kagoshima prefecture, and proved that Shippi was superior in utility to putty as air-tight materials in wooden-ship building
Cartilage putty: A novel use of fibrin glue with morselised cartilage grafts for rhinoplasty surgery
No full textCartilage grafts have multiple purposes within rhinoplasty surgery. The senior author has previously used wrapped diced cartilage grafts but found it difficult to maintain the integrity of the graft "package" during placement. Introduction of Tisseel fibrin glue stabilises the cartilage fragments producing a rubbery mass that can be used like "cartilage putty." This malleable construct can be inserted and moulded with less risk of dispersal.This technique has now been used on nineteen patients. It has provided a valuable method of reconstruction especially in complex cases such as revision rhinoplasty and patients with a thin dorsal skin envelope. There has been no evidence of graft absorption or requirement for additional surgery to date.The addition of Tisseel to wrapped diced cartilage grafts, has proven in this series of complex rhinoplasty patients, to be a useful adjunct which aids insertion and contouring. Furthermore, beneficial effects on healing have been demonstrated which contributes to good quality long-term cosmetic results.Level of Evidence V. (C) 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved
(the Effects Temperature and RotationSpeed of Mollen Dryer on the Characteristic S of Aloe Vera Co-crystalization)
No full textThe research is aimed to study the effect of temperature and rotation speed of mollen dryer on the characteristic of (aloe vera linn)co-crystalization.The temperature usedwere 55 degree C,60 degree C,and 65 degree C.The rotation speeds of mollen dryer are 12 rpm, 18 rpm, and 24 rpm respectively.The experimental design was the factorial random design with two replications. The result showed the best product was obtained from temperature of 60 degree C and 18 rpm rotation speed of mollen dryer.The composition of the dried aloe vera is :total sugar 56.18%,moisture content 0,84%,fiber content 0.92% and the solubility is 98.31%.While organoleptically (taste,texture,aroma,and appearane)the product was acceptabl
Experimental analysis of lime putty and pozzolan-based mortar for interventions in archaeological sites
Full text linkThe study aims at defining and characterizing a specific restoration mortar for archaeological
masonry structures made with traditional materials
and to assess the suitability of the mixture compared to
other mortars; such a goal is crucial to develop and
define interventions in the archaeological sites. The
mixture was defined to ensure compatibility with
ancient materials and following frequently adopted
recommendations at the site, specifically by using: (1)
raw materials as similar as possible to the ancient ones;
(2) traditional mix design. Therefore, the mixture was
made with commercial lime putty CL 90-S type and
natural Phlegrean pozzolan, i.e. volcanoclastic material collected from the volcanic area located in the
West of Naples in Italy. The precious and limitedly
available natural pozzolan used in the experiments
resulted in an exclusive mortar which is very similar to
the archaeological ones. The mortar has a binder to
aggregate ratio 1:3 by volume, according to traditional
techniques typically encountered in the ancient
Roman city of Pompeii and Vesuvius surrounding
area. The evolution of the flexural and compressive
strength, elastic modulus, bulk density, open porosity
and ultrasonic pulse velocity has been monitored for
up to 200 days, based on standard procedures. Moreover, the hardening process was monitored with
Differential Thermal Analysis up to 90 days, through
the evaluation of phase transitions associated with
dehydroxylation and decarboxylation, considering
different depths from the external surface of the
mortar. The achieved mechanical properties were
compatible with those of lime-based mixtures for
repair interventions of ancient masonry structures.
Moreover, the mortar was found to be well-suited to
mitigate cracking, showing a low ratio between its
stiffness and load capacity compared to other typologies of mortars used for masonry restoration. Ultrasonic pulse velocity test proved to be a reasonable
complementary method to monitor the evolution of the
hardened properties of the mortar. Carbonation was
found to be still progressing at 90 days. The data
presented provide useful and reliable information to
approach the complex process of restoration in
archeological sites.Open access funding provided by Universita degli Studi di Napoli Federico II within the CRUI-CARE Agreement. This study was supported by the PhD research program in Industrial Product and Process Engineering, at the University of Naples Federico II attributed to the first author. Grants were also provided by the Portuguese Foundation for Science and Technology FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020 and by national funds through FCT-Foundation for Science and Technology, under grant agreement (SFRH/BD/137358/2018) attributed to the second author
The Role of Aging on Rheological Properties of Lime Putty
No full textAbstractThe role of aging on rheological properties of lime putties was investigated by rotational rheometry, scanning electron microscopy and particle size distribution analyzes. Disaggregation of large clusters during aging and resulting microstructural enrichment of micron-sized particles was found to be one of the possible reasons for the continuous increment of plasticity and yield stress of lime putties during long-term aging. The extent of thixotropic and rheopectic behavior is affected by both calcination process and microstructure development during aging
