scholarly journals A Micro-Scale Investigation on the Behaviors of Asphalt Mixtures under Freeze-Thaw Cycles Using Entropy Theory and a Computerized Tomography Scanning Technique

Entropy ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 68 ◽  
Author(s):  
Huining Xu ◽  
Hengzhen Li ◽  
Yiqiu Tan ◽  
Linbing Wang ◽  
Yue Hou
Keyword(s):  
Computerized Tomography ◽  
Asphalt Mixtures ◽  
Entropy Theory ◽  
Freeze Thaw ◽  
Micro Scale ◽  
Scanning Technique ◽  
Tomography Scanning

Degradation of asphalt mixtures with glass aggregates subjected to freeze-thaw cycles

2017 ◽  
Vol 141 ◽  
pp. 8-15 ◽  
Author(s):  
Éric Lachance-Tremblay ◽  
Daniel Perraton ◽  
Michel Vaillancourt ◽  
Hervé Di Benedetto
Keyword(s):  
Asphalt Mixtures ◽  
Freeze Thaw

Effectiveness of Loaded Wheel Tracking Test to Ascertain Moisture Susceptibility of Asphalt Mixtures

2021 ◽  
pp. 036119812110363
Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Moisture Susceptibility ◽  
Freeze Thaw ◽  
Wheel Tracking ◽  
Mixture Samples

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.

Measurement Method of X-ray Focus Projection Coordinates of Three-Dimensional Micro-Computerized Tomography Scanning System

2009 ◽  
Vol 29 (5) ◽  
pp. 1275-1280
Author(s):  
杨民 Yang Min ◽  
刘静华 Liu Jinghua ◽  
李保磊 Li Baolei ◽  
吴文晋 Wu Wenjin ◽  
王钢 Wang Gang
Keyword(s):  
Computerized Tomography ◽  
Measurement Method ◽  
Three Dimensional ◽  
Scanning System ◽  
X Ray ◽  
Tomography Scanning ◽  
Focus Projection

scholarly journals Study on Viscoelastic Properties of Asphalt Mixtures Incorporating SBS Polymer and Basalt Fiber under Freeze–Thaw Cycles

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1804
Author(s):  
Wensheng Wang ◽  
Guojin Tan ◽  
Chunyu Liang ◽  
Yong Wang ◽  
Yongchun Cheng
Keyword(s):  
Viscoelastic Properties ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Asphalt Mixtures ◽  
Freeze Thaw ◽  
Static Creep ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Static Creep Test ◽  
Butadiene Styrene

This study aims to study the viscoelastic properties of asphalt mixtures incorporating styrene–butadiene–styrene (SBS) polymer and basalt fiber under freeze–thaw (F-T) cycles by using the static creep test. Asphalt mixture samples incorporating styrene–butadiene–styrene (SBS) polymer and basalt fiber were manufactured following the Superpave gyratory compaction (SGC) method and coring as well as sawing. After 0 to 21 F-T cycles processing, a uniaxial compression static creep test for the asphalt mixture specimens was performed to evaluate the influence of F-T cycles. The results indicated that the F-T cycles caused a larger creep deformation in the asphalt mixtures, which led to a decrease in the rut resistance of the asphalt mixtures incorporating SBS polymer and basalt fiber. Besides, the resistance to deformation decreased significantly in the early stage of F-T cycles. On the other hand, the viscoelastic parameters were analyzed to discuss the variation of viscoelastic characteristics. The relaxation time increased with F-T cycles, which will not be conducive to internal stress dissipation. Compared with lignin fiber, basalt fiber can improve the resistance to high-temperature deformation and the low-temperature crack resistance of asphalt mixtures under F-T cycles.

A simple, inexpensive technique for accurate mass localization by computerized tomography

1980 ◽  
Vol 52 (5) ◽  
pp. 733-735 ◽  
Author(s):  
John I. Moseley ◽  
Steven L. Giannotta ◽  
Justin W. Renaudin
Keyword(s):  
Computerized Tomography ◽  
Accurate Mass ◽  
Content Type ◽  
Accurate Localization ◽  
Relationship Of ◽  
The Relationship ◽  
Inexpensive Technique ◽  
Tomography Scanning ◽  
Fine Print

✓ A simple wire template is placed on the patient's head during computerized tomography scanning, and the results of the scan are later reproduced on the scalp prior to surgery. Measurements of the distance between the wires and the relationship of the mass provide the key to accurate localization of the mass on the scalp surface.

Fatal subarachnoid hemorrhage after endoscopic third ventriculostomy

1999 ◽  
Vol 90 (1) ◽  
pp. 153-155 ◽  
Author(s):  
Henry W. S. Schroeder ◽  
Rolf W. Warzok ◽  
Jamal A. Assaf ◽  
Michael R. Gaab
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Computerized Tomography ◽  
Endoscopic Third Ventriculostomy ◽  
Obstructive Hydrocephalus ◽  
Balloon Catheter ◽  
Third Ventriculostomy ◽  
Safe Procedure ◽  
Content Type ◽  
Tomography Scanning ◽  
Fine Print

✓ In recent years, endoscopic third ventriculostomy has become a well-established procedure for the treatment of various forms of noncommunicating hydrocephalus. Endoscopic third ventriculostomy is considered to be an easy and safe procedure. Complications have rarely been reported in the literature. The authors present a case in which the patient suffered a fatal subarachnoid hemorrhage (SAH) after endoscopic third ventriculostomy.This 63-year-old man presented with confusion and drowsiness and was admitted in to the hospital in poor general condition. Computerized tomography scanning revealed an obstructive hydrocephalus caused by a tumor located in the cerebellopontine angle. An endoscopic third ventriculostomy was performed with the aid of a Fogarty balloon catheter. Some hours postoperatively, the patient became comatose. Computerized tomography scanning revealed a severe perimesencephalic—peripontine SAH and progressive hydrocephalus. Despite emergency external ventricular drainage, the patient died a few hours later.Although endoscopic third ventriculostomy is considered to be a simple and safe procedure, one should be aware that severe and sometimes fatal complications may occur. To avoid vascular injury, perforation of the floor of the third ventricle should be performed in the midline, halfway between the infundibular recess and the mammillary bodies, just behind the dorsum sellae.

Dermoid tumors occurring at the site of previous myelomeningocele repair

1986 ◽  
Vol 65 (6) ◽  
pp. 779-783 ◽  
Author(s):  
R. Michael Scott ◽  
Samuel M. Wolpert ◽  
Louis E. Bartoshesky ◽  
Seymour Zimbler ◽  
George T. Klauber
Keyword(s):  
Differential Diagnosis ◽  
Lower Extremity ◽  
Computerized Tomography ◽  
Neurological Deterioration ◽  
Bladder Function ◽  
Content Type ◽  
Surgical Exploration ◽  
Myelomeningocele Repair ◽  
Tomography Scanning ◽  
Fine Print

✓ Four children with previously repaired myelomeningoceles presented toward the end of the first decade or early in the second decade of life with deteriorating lower-extremity and bladder function. Myelography and computerized tomography scanning demonstrated irregular filling defects at the area of the myelomeningocele repair, and surgical exploration disclosed dermoid tumors that were adherent to the placode and adjacent roots. Dermoid tumors should be considered in the differential diagnosis of neurological deterioration in children with a repaired myelomeningocele.

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