scholarly journals Comparison Study of Dynamic Elastic Moduli of Cement Mortar and No-cement Slag Based Cementitious Mortar Activated with Calcined Dolomite with Impulse Excitation Technique

2018 ◽  
Vol 186 ◽  
pp. 02004
Author(s):  
Herry Suryadi Djayaprabha ◽  
Ta-Peng Chang ◽  
Jeng-Ywan Shih
Keyword(s):  
Compressive Strength ◽  
Shear Modulus ◽  
Elastic Moduli ◽  
Cement Mortar ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Shear Moduli ◽  
Dynamic Young’S Modulus ◽  
Impulse Excitation ◽  
Dynamic Elastic Moduli

This paper presents the comparison of an experimental investigation on compressive strength and dynamic elastic moduli of mortars made of Ordinary Portland Cement (OPC) and ground granulated blast furnace slag (GGBFS) incorporating with calcined dolomite. Dolomite powder calcined at temperature 900°C emerged as a GGBFS activator for producing cementitious mortar binder. In this study, no-cement mortar is made by activating GGBFS with calcined dolomite by a fixed amount of 20 wt%. The compressive strengths and dynamic elastic moduli were measured at 7 and 28 days. Comparing with cement mortar, the compressive strength of no-cement mortar was found about 54.4 and 46.9% lower at ages of 7 and 28 days, respectively. Non-destructive evaluation of the dynamic elastic moduli was investigated by impulse excitation technique (IET). It measures the resonant frequencies of induced vibration signal in the flexural and torsional mode for determining the dynamic Young's modulus and the dynamic shear modulus. The Poisson's ratio was calculated by the dynamic Young's modulus and the dynamic shear modulus relationship. The results showed that the 28-day dynamic Young's and shear moduli of cement mortar were 31.91 and 14.43 GPa, respectively. The dynamic Young's and shear moduli of no-cement mortar were lower by 23.3 and 15.2% than that of cement mortar at the age of 28 days. The obtained results showed that the 28-day Poisson's ratio of no-cement mortar had a wider range between 0.177 and 0.209 than that of cement mortar which ranged from 0.180 to 0.185.

Variation in dynamic elastic shear modulus of sandstone upon fluid saturation and substitution

Geophysics ◽  
2003 ◽  
Vol 68 (2) ◽  
pp. 472-481 ◽  
Author(s):  
Jalal Khazanehdari ◽  
Jeremy Sothcott
Keyword(s):  
Shear Modulus ◽  
Elastic Moduli ◽  
Frequency Dispersion ◽  
Dynamic Shear Modulus ◽  
Ultrasonic Frequency ◽  
Dynamic Shear ◽  
Fluid Saturation ◽  
Dynamic Elastic Moduli ◽  
Rock Microstructure ◽  
Elastic Shear

Experimental acoustic measurements on sandstone rocks at both sonic and ultrasonic frequencies show that fluid saturation can cause a noticeable change in both the dynamic bulk and shear elastic moduli of sandstones. We observed that the change in dynamic shear modulus upon fluid saturation is highly dependent on the type of saturant, its viscosity, rock microstructure, and applied pressures. Frequency dispersion has some influence on dynamic elastic moduli too, but its effect is limited to the ultrasonic frequency ranges and above. We propose that viscous coupling, reduction in free surface energy, and, to a limited extent, frequency dispersion due to both local and global flow are the main mechanisms responsible for the change in dynamic shear elastic modulus upon fluid saturation and substitution, and we quantify influences.

Development of Mechanical Properties of Cement Paste with Different Addition of Polyvinyl Alcohol

2015 ◽  
Vol 732 ◽  
pp. 81-84 ◽  
Author(s):  
Jaroslav Topič ◽  
Pavel Tesárek ◽  
Václav Nežerka ◽  
Zdeněk Prošek ◽  
Tomáš Plachy
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Polyvinyl Alcohol ◽  
Cement Paste ◽  
Resonance Method ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Alcohol Content ◽  
Dynamic Young’S Modulus ◽  
Dynamic Young's Modulus

This paper deals with using resonance method for determine the development of the mechanical properties of cement paste with different polyvinyl alcohol content. Main properties which were monitored are the dynamic Young’s modulus and dynamic shear modulus. Those properties were measured during 161 days for better understanding of influence of Polyvinyl Alcohol (PVA) added in the cement paste. Difference between this paper and already published articles is in several parameters. Main difference is that samples in this paper were cured on air, not in water. Moreover was used higher amount of polyvinyl alcohol on modification of cement paste.

scholarly journals Novel 2D Dynamic Elasticity Maps for Inspection of Anisotropic Properties in Fused Deposition Modeling Objects

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1966 ◽  
Author(s):  
Yuqi Jin ◽  
Teng Yang ◽  
Hyeonu Heo ◽  
Arkadii Krokhin ◽  
Sheldon Q. Shi ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Fused Deposition Modeling ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Fused Deposition ◽  
Dynamic Young’S Modulus ◽  
Deposition Modeling ◽  
3D Printed ◽  
Dynamic Young's Modulus ◽  
Non Destructive

In this study, a novel ultrasonic non-destructive and non-invasive elastography method was introduced and demonstrated to evaluate the mechanical properties of fused deposition modeling 3D printed objects using two-dimensional dynamical elasticity mapping. Based on the recently investigated dynamic bulk modulus and effective density imaging technique, an angle-dependent dynamic shear modulus measurement was performed to extract the dynamic Young’s modulus distribution of the FDM structures. The elastographic image analysis demonstrated the presence of anisotropic dynamic shear modulus and dynamic Young’s modulus existing in the fused deposition modeling 3D printed objects. The non-destructive method also differentiated samples with high contrast property zones from that of low contrast property regions. The angle-dependent elasticity contrast behavior from the ultrasonic method was compared with conventional and static tensile tests characterization. A good correlation between the nondestructive technique and the tensile test measurements was observed.

Rubber-Thermoplastic Compositions. Part III. Predicting Elastic Moduli of Melt Mixed Rubber-Plastic Blends

1981 ◽  
Vol 54 (1) ◽  
pp. 91-100 ◽  
Author(s):  
A. Y. Coran ◽  
R. Patel
Keyword(s):  
Shear Modulus ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Material Selection ◽  
Adjustable Parameter ◽  
Dynamic Shear Modulus ◽  
Torsion Pendulum ◽  
Molten State ◽  
Dynamic Shear ◽  
The Individual

Abstract Blends prepared by mixing rubbers with plastics in the molten state have been known and used for a number of years. The stiffness of such blends vary widely with both the proportions of rubber to plastic and with material selection, even at equivalent rubber to plastic proportions. This report describes correlations between blend stiffness and the properties of the individual blend components. Dynamic shear modulus G′, determined by torsion pendulum measurements, was used to characterize the stiffnesses of the blends. Values of G′ were related to the moduli of the hard and soft (plastic and rubber) phases, G′H and G′S, and the volume fraction of plastic ϕH through a single adjustable parameter by means of a recently proposed relationship. The adjustable parameter was then correlated with other properties of the blend components. In contrast with the work reported in the first two papers of this series, this report is on compositions in which the rubber is not crosslinked.

Shear moduli and damping in frozen and unfrozen clay by resonant column tests

1996 ◽  
Vol 33 (3) ◽  
pp. 510-514 ◽  
Author(s):  
M O Al-Hunaidi ◽  
P A Chen ◽  
J H Rainer ◽  
M Tremblay
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Frozen Soil ◽  
Test Method ◽  
Dynamic Shear Modulus ◽  
Resonant Column ◽  
Dynamic Shear ◽  
Column Test ◽  
Shear Moduli ◽  
Resonant Column Test

The resonant-column test method was used in this study to determine the dynamic shear moduli and damping ratios of frozen and unfrozen soil samples. Naturally frozen soil specimens were obtained in-situ during the winter. A series of tests were carried out on the frozen soil specimens in a cold room at –9°C. The same specimens, after allowing them to thaw, were then tested at room temperature. Test results show that at low-amplitude shear stains the damping ratio of frozen soil specimens is roughly twice that of unfrozen samples. In addition, the dynamic shear modulus for soil specimens while frozen is significantly greater (30 or 50 times) than that of unfrozen specimens. These results provide a basis for explaining an observation that bus-induced vibrations in buildings while the top soil is frozen in winter are about one-half those induced while the soil is not frozen. Key words: resonant-column test, shear modulus, damping ratio, frozen soil, ground vibration.

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