scholarly journals The Los Angeles test in the European standardisation system

2002 ◽  
Vol 54 (4) ◽  
pp. 106-111
Author(s):  
Endre Árpás ◽  
Gyula Emszt ◽  
Miklós Gálos ◽  
László Kárpáti
Keyword(s):  
Los Angeles ◽  
Los Angeles Test

The Use of Recycled Aggregates in Continuously Reinforced Concrete Pavements (CRCP)

2013 ◽  
Vol 711 ◽  
pp. 391-395
Author(s):  
Hans de Backer
Keyword(s):  
Reinforced Concrete ◽  
Los Angeles ◽  
Drying Shrinkage ◽  
Recycled Aggregates ◽  
Concrete Layer ◽  
Los Angeles Test ◽  
Component Material ◽  
Ecological Importance ◽  
Natural Aggregates ◽  
The Impact

The use of recycled aggregates in concrete has increased in recent decades. Increasing scarcity of natural aggregates and the growing ecological importance promote this evolution. The first test section in Belgium of a two-layer continuously reinforced concrete pavement (CRCP) with recycled aggregates in the substrate layer was built on the highway E34/N49 in 2007. Horizontal cracking at the level of the reinforcement showed up after only a few years. This is a problem which was never seen before in CRCP and was probably due to the use of recycled aggregates. Therefore it is important to understand the impact of recycled aggregates on concrete. Recycled aggregates are a two-component material consisting of natural aggregates and adhering mortar. The adhering mortar is more porous than the rock particles which insures a higher water absorption and lower density. In addition, they have a lower abrasion loss in the Los Angeles-test and less resistance against weather and temperature changes. This is due to, respectively, the less strong mortar content, and the large pores of recycled granulates. A first cause of horizontal cracking can be found in the results of high drying shrinkage, high creep and low modulus of elasticity. These properties insure larger tensions in the concrete layer. In combination with a lower tensile strength it is a possible cause for the horizontal cracking. In addition, the paper reports on laboratory testing concerning the properties of concrete with recycled aggregates and discusses an alternative method to determine the concrete mixture which takes the influence of the adhering mortar into account.

scholarly journals Study Concerning Characterization of Some Recycled Concrete Aggregates

2016 ◽  
Vol 12 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Ion Robu ◽  
Claudiu Mazilu ◽  
Radu Deju
Keyword(s):  
Los Angeles ◽  
Road Construction ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Mechanical Resistance ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Los Angeles Test ◽  
Water Behavior ◽  
Natural Aggregates

Abstract Using recycled concrete aggregates (RCA) is a matter of high priority in the construction industry worldwide. In countries like the Netherlands, Denmark, Germany, USA, Japan, France recycled concrete aggregates obtained from demolition are valorized up to 90%, mainly for road construction and less in the manufacture of new concrete. Recycled concrete aggregates (RCA) generally result from a two-stage crushing of the concrete obtained from demolition followed by the screening and removal of contaminants (wood, plastic, metal, ceramics etc.). The literature review showed that the recycled aggregates concrete (RAC) are less resistant, with 15 to 40% versus concrete obtained using natural aggregates. The factors that play a role in the reducing of mechanical resistance are presented and analyzed in this study. This paper presents a study on the use of recycled aggregates, from a concrete of specified class, to acquire new cement concrete with different percentages of recycled aggregates. In order to evaluate the influence upon the properties of the new concrete obtained, recycled aggregates have been characterized in terms of the granulosity, the granule shape, the absorption of water, behavior to the Los Angeles test, the content of attached mortar etc.

scholarly journals Utilization of Oyster Shells as a Substitute Part of Cement and Fine Aggregate in the Compressive Strength of Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 150-156
Author(s):  
Bunyamin Bunyamin ◽  
Amir Mukhlis
Keyword(s):  
Compressive Strength ◽  
Los Angeles ◽  
Oyster Shell ◽  
Partial Substitution ◽  
Test Machine ◽  
Fine Aggregate ◽  
Cement Replacement ◽  
Los Angeles Test ◽  
Concrete Production ◽  
Compressive Strength Of Concrete

The compressive strength of concrete depends on the physical characteristics of the concrete forming materials. Oyster shells originating from Krueng Neng, Aceh Besar are very abundant, left unattended by fishermen, causing pollution of the surrounding environment. Oyster shell dust contains CaO, which can be used as a partial substitution of cement. Therefore, it is necessary to study oyster shell ash as cement replacement and fine aggregate in concrete production. This research aims to determine the compressive strength of concrete using shell ash as cement replacement and fine aggregate. The oyster shells were obtained from Krueng Neng, Lamjamee Village, Jaya Baru, Aceh Besar District. The oyster shells were crushed with a Los Angeles Test machine and sieved with sieve size 2.36 mm for fine aggregate and sieve #200 for cement replacement. The water-cement ratios (w/c) were 0.4, 0.5 and 0.6. The results showed that concrete's compressive strength with 5% cement replacement level was higher than the concrete with cement only. Meanwhile, for other replacement levels, the compressive strengths of concrete specimens were lower than control specimens.  

Sinusoidal Cells in Bone Marrow Take Up BSA-Au Conjugates in the Presence of an Artificial Blood Substitute

1985 ◽  
Vol 43 ◽  
pp. 700-701
Author(s):  
J.S. Geoffroy ◽  
R.P. Becker
Keyword(s):  
Bone Marrow ◽  
Los Angeles ◽  
Iliac Artery ◽  
Blood Substitute ◽  
Sprague Dawley ◽  
Coated Pits ◽  
Sinusoidal Cells ◽  
Artificial Blood ◽  
Left Common Iliac Artery

The pattern of BSA-Au uptake in vivo by endothelial cells of the venous sinuses (sinusoidal cells) of rat bone marrow has been described previously. BSA-Au conjugates are taken up exclusively in coated pits and vesicles, enter and pass through an “endosomal” compartment comprised of smooth-membraned tubules and vacuoles and cup-like bodies, and subsequently reside in multivesicular and dense bodies. The process is very rapid, with BSA-Au reaching secondary lysosmes one minute after presentation. (Figure 1)In further investigations of this process an isolated limb perfusion method using an artificial blood substitute, Oxypherol-ET (O-ET; Alpha Therapeutics, Los Angeles, CA) was developed. Under nembutal anesthesia, male Sprague-Dawley rats were laparotomized. The left common iliac artery and vein were ligated and the right iliac artery was cannulated via the aorta with a small vein catheter. Pump tubing, preprimed with oxygenated 0-ET at 37°C, was connected to the cannula.

Interprofessional Collaboration to Promote Culturally Engaged and Strengths-Based Practice

2020 ◽  
Vol 5 (6) ◽  
pp. 1410-1421
Author(s):  
Erica Ellis ◽  
Mary Kubalanza ◽  
Gabriela Simon-Cereijido ◽  
Ashley Munger ◽  
Allison Sidle Fuligni
Keyword(s):  
Los Angeles ◽  
Training Program ◽  
Interprofessional Education ◽  
Clinical Training ◽  
Interprofessional Collaboration ◽  
Communication Disorders ◽  
Outreach Program ◽  
State University ◽  
Diversity And Inclusion ◽  
Health Nursing

Purpose To effectively prepare students to engage in interprofessional practice, a number of Communication Disorders (COMD) programs are designing new courses and creating additional opportunities to develop the interprofessional competencies that will support future student success in health and education-related fields. The ECHO (Educational Community Health Outreach) program is one example of how the Rongxiang Xu College of Health and Human Services at California State University, Los Angeles, has begun to create these opportunities. The ultimate goal of the ECHO project is to increase both access to and continuity of oral health care across communities in the greater Los Angeles area. Method We describe this innovative interdisciplinary training program within the context of current interprofessional education models. First, we describe the program and its development. Second, we describe how COMD students benefit from the training program. Third, we examine how students from other disciplines experience benefits related to interprofessional education and COMD. Fourth, we provide reflections and insights from COMD faculty who participated in the project. Conclusions The ECHO program has great potential for continuing to build innovative clinical training opportunities for students with the inclusion of Child and Family Studies, Public Health, Nursing, and Nutrition departments. These partnerships push beyond the norm of disciplines often used in collaborative efforts in Communication Sciences and Disorders. Additionally, the training students received with ECHO incorporates not only interprofessional education but also relevant and important aspects of diversity and inclusion, as well as strengths-based practices.

Vorhersagbarkeit posttraumatischer Belastung bei Kindern und Jugendlichen nach traumatischen Ereignissen in der Schule

2008 ◽  
Vol 17 (4) ◽  
pp. 219-223 ◽  
Author(s):  
Barbara Frühe ◽  
Hans-Joachim Röthlein ◽  
Rita Rosner
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Los Angeles ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Reaction Index ◽  
Traumatische Ereignisse

Traumatische Ereignisse im schulischen Kontext treten vergleichsweise häufig auf. So ist die Bestimmung von Kindern und Jugendlichen, die aktuell und auch zu einem späteren Zeitpunkt einer psychologischen Betreuung bedürfen, im Rahmen der Fürsorgepflicht notwendig. 48 Jugendliche zwischen 12 und 17 Jahren wurden in der Schule zu zwei Messzeitpunkten zur akuten und posttraumatischen Symptomatik sowie zu verschiedenen Risikofaktoren befragt. Verwendet wurde die neu entwickelte Checkliste zur Akuten Belastung (CAB) und die deutsche Version des University of Los Angeles at California Posttraumatic Stress Disorder Reaction Index (UCLA CPTSD-RI). Eine Woche nach dem Ereignis betrug der Anteil klinisch bedeutsamer Belastung 21 % und nach 10 – 15 Wochen 10 %. Ein mittlerer Zusammenhang zwischen akuter und posttraumatischer Belastung konnte nachgewiesen werden. Als bedeutsame Risikofaktoren für die Entwicklung einer posttraumatischen Belastung stellten sich der Konfrontationsgrad, peritraumatisch erlebte Angst sowie akute Beeinträchtigung heraus. Im Kontext der Betreuung betroffener Jugendlicher nach traumatischen Ereignissen sollte den Risikofaktoren mehr Beachtung geschenkt werden.

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