Novel Analysis of Ultrasonic Pulse Propagation Tests for Characterization of Asphalt Concrete

2021 ◽  
Vol 50 (2) ◽  
pp. 20210239
Author(s):  
Pejoohan Tavassoti ◽  
Taher H. Ameen ◽  
Hassan Baaj ◽  
Giovanni Cascante
Keyword(s):  
Asphalt Concrete ◽  
Pulse Propagation ◽  
Ultrasonic Pulse

Ultrasonic pulse propagation in inhomogeneous one-dimensional media

1998 ◽  
Vol 104 (1) ◽  
pp. 57-63 ◽  
Author(s):  
N. Cretu ◽  
P. P. Delsanto ◽  
G. Nita ◽  
C. Rosca ◽  
M. Scalerandi ◽  
...  
Keyword(s):  
Pulse Propagation ◽  
Ultrasonic Pulse ◽  
One Dimensional

Characterization of Polypropylene Staple Yarns by Acoustic Dynamic Modulus

2013 ◽  
Vol 586 ◽  
pp. 3-7
Author(s):  
Dana Kremenakova ◽  
Jiří Militký ◽  
Juan Huang
Keyword(s):  
Dynamic Modulus ◽  
Pulse Propagation ◽  
Tensile Modulus ◽  
Polypropylene Fibers ◽  
Orientation Factor ◽  
Cross Sectional ◽  
Indirect Measure ◽  
Yarn Twist ◽  
Propagation Technique

The acoustic or sonic pulse-propagation technique for the measurement of dynamic elastic modulus has the advantage of not being dependent on the sample cross-sectional characteristics. This technique also gives a direct measure of modulus rather than the indirect measure in the form of load versus extension. The sonic tests are relatively simple to apply and are nondestructive. The values of sonic modulus of fibrous structures are dependent on the orientation of components and packing density as well. The main aim of this work is to quantify effect of yarn twist on the sonic modulus of staple yarns from polypropylene fibers. The results are compared with selected models of yarn twist influence on the mechanical properties of staple yarns. The correlation between yarn orientation factor defined by Pan and sonic modulus are shown. The sonic modulus is compared with tensile modulus of yarns.

scholarly journals Reología, comportamiento físico-mecánicos y de durabilidad de hormigones con nanosílice.

2012 ◽  
Vol 2 (2) ◽  
pp. 82-88
Author(s):  
E. Téllez Girón ◽  
A .N. Martín Acosta ◽  
A. Pérez Hernández ◽  
U. Verdecia Rodríguez
Keyword(s):  
Resistance Coefficient ◽  
Ultrasonic Pulse ◽  
Effective Porosity ◽  
Capillary Absorption ◽  
Water Absorption Coefficient ◽  
Characterization Methods ◽  
Natural Pozzolans ◽  
Chemical Admixtures ◽  
Microscopy Analysis

RESUMENLa nanosílice es una de las aplicaciones de la nanotecnologia en la construcción, a base de sílica amorfa nanométrica, que se emplea igual que la microsílice, pero con la ventaja que no produce contaminación al medio ambiente y la agresión a la salud por inhalación de ésta. Se dan los resultados de la caracterización física de dos compuestos de nanosílice comerciales mediante los métodos de la caracterización de aditivos y el empleo de la microscopia para la determinación de compuestos fundamentales, de sus actividades puzolánicas en morteros, así como la determinación de la absorción capilar, velocidad ultrasónica, masa volumétrica, coeficientes de resistencia a la penetración de agua, coeficiente de absorción de agua y porosidad efectiva en hormigones elaborados con los compuestos evaluados y en hormigones con aditivos superplastificantes y tobas zeolitizadas como patrones de comparación. Los valores demuestran un mejor comportamiento de durabilidad en los hormigones elaborados con nanosílice.Palabras Clave: nanotecnología; nanosílice; microsílice; aditivos químicos; adiciones.ABSTRACTNanosilice based in nanometric amorphous silica is one of the aplications of nanotechnology in the building industry, that has the same use than microsilica, but with the advantage that it does not produce environmental pollution or respiratory complains due to inhalation. We give the results of the physical characterization of two commercial nanosilice compounds by the admixtures characterization methods and electronic microscopy analysis to determine the fundamental compound, its pozzolanic activity in mortars, as well as its capillary absorption, ultrasonic pulse speed, volumetric mass, water penetration resistance coefficient, water absorption coefficient and effective porosity in concrete with nanosilice and in ordinary concrete with natural pozzolans and superplasticizer admixtures like comparative patterns. Results show a better behavior of durability in concretes with nanosilice.Keywords: nanotechnology; nanosilica; microsilica; chemical admixtures; additions.

scholarly journals Influence of the surroundings areas in the microclimates of Santo André City – Brazil and Indication of Bioclimatic Strategies for Buildings

2019 ◽  
Vol 111 ◽  
pp. 06005
Author(s):  
Helenice Maria Sacht ◽  
Andréa de Oliveira Cardoso ◽  
Victor Figueiredo Roriz
Keyword(s):  
Asphalt Concrete ◽  
Weather Data ◽  
Heat Island ◽  
Paulo State ◽  
Urban Heat ◽  
Air Circulation ◽  
The City ◽  
New Buildings ◽  
Great Absorption

The characterization of the climate of Santo André and its weather data are essential instruments for the study of implantation, both of new buildings and solutions of retrofit, as well as for the elaboration of projects of urban interventions or degraded areas occupation. In this study, meteorological weather data were obtained by meteorological stations in Santo André, a municipality located in the region of ABC Paulista (São Paulo State), for five different points of the city in order to evaluate the different micro climates and the influence of the surroundings in microclimates and an climate file in .epw format was developed for analysed bioclimatic strategies for buildings. Results show temperature and humidity variations among the five microclimates analyzed, as a consequence of the following actions: replacement of vegetation by constructions, asphalt, concrete and other impermeable surfaces, increased air pollution which cause a great absorption of solar radiation, forming a barrier for air circulation and of pollutant gases into the atmosphere creating urban heat island effects.

Influence of Clutch Disc Waste (Grinding Dust) on Portland Cement Hydration

2019 ◽  
Vol 803 ◽  
pp. 284-288
Author(s):  
José da Silva Andrade Neto ◽  
Tiago Assunção Santos ◽  
Raphael Dias Mariano ◽  
Marcio Raymundo Morelli ◽  
Daniel Véras Ribeiro
Keyword(s):  
Portland Cement ◽  
Propagation Velocity ◽  
Pulse Propagation ◽  
Cement Hydration ◽  
Setting Time ◽  
Reference Sample ◽  
Ultrasonic Pulse ◽  
X Ray Diffraction ◽  
Copper Zinc ◽  
Portland Cement Hydration

This paper evaluates the effect of grinding dust (GD), a waste generated in the clutch disc finishing process, on Portland cement hydration. For this, pastes with additions of 5%, 10% and 15% GD, relative to cement weight, were molded and compared with a reference sample. Tests of setting time determination by Vicat needle, calorimetry, monitoring the ultrasonic pulse propagation velocity and mineralogical analysis (X-ray diffraction) in pastes with 1 day of hydration were carried out. It was observed that GD, due to the presence of copper, zinc and phenolic resin in its composition, is responsible for retarding cement hydration and thus increases the setting time and delays the evolution of heat release and pulse propagation velocity. However, the formation of new crystalline phases was not observed.

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