Schleibinger Testing Systems

Alkali-Silica-Reactor

 

Detection of Potential Alkali-Reactivity-60°C Accelerated method with the Schleibinger ASR-Reactor - Standards:

 

Alkali-Silica-Reactivity

Alkali-silica reactivity is the process in which certain minerals (mostly glass type silica) in the presence of moisture are broken down by the highly alkaline environment of concrete producing a gel that expands creating tensile forces in the concrete matrix which cause cracking of the concrete. The cracking then allows more water to infiltrate into the concrete creating more gel, more expansion etc. Ultimately the concrete fails or disintegrates. Typical indicators of ASR are random map cracking and, in advanced cases, closed joints and attendant spalled concrete. Cracking due to ASR usually appears in areas with a frequent supply of moisture, such as close to the waterline in piers, near the ground behind retaining walls, near joints and free edges in pavements, or in piers or columns subject to wicking action. Petrographic examination can conclusively identify ASR. http://www.cement.org/tech/cct_dur_AAR.asp

(** http://www.cement.org/tech/faq_ASR.asp Portland Cement Assosication, Skokie, IL, USA

 

Schleibinger developed the ASR tester. In this test chamber concrete specimen are stored at a temperature between 20°C and 70°C at nearly 100% rel. Humidity according to the French standard NF P18-454 (Décembre 2004) : Béton - Réactivité d'une formule de béton vis-à-vis de l'alcali-réaction - Essai de performance and the RILEM test method TC 101-ARP AAR-4 -Detection of Potential Alkali-Reactivity- Accelerated method for testing aggregate combinations using concrete prisms - . The temperature deviation herein is below 0.5K. The temperature is registered continuously and displayed graphically. Over an Internet interface, the Schleibinger ACR-tester maybe controlled remotely.

Standards

• Deutscher Ausschuss für Stahlbeton, DAfSTb (Hrsg.): Vorbeugende Maßnamen gegen schädigende Alkalireaktionen im Beton: Alkali-Richtlinie, Anhang B, Teil3, Berlin: Beuth, 2007
  
  
• Standard NF P18-454 (Décembre 2004) : Béton - Réactivité d'une formule de béton vis-à-vis de l'alcali-réaction - Essai de performance - Reactivity of concrete for alkali-silica Performance test 
  
  
• RILEM Test Method TC 191-ARP (Ed.): AAR-4.1: -Detection of Potential Alkali-Reactivity-60°C Accelerated method for testing aggregate combinations using concrete prisms - Bagneaux, 2006
  
  
• ASTM C1567 -8 : Standard Test Method for Determining the Potential Alkali-Silica Reactivity of Combinations of Cementitious Materials and Aggregate (Accelerated Mortar-Bar Method)
  
  
• ASTM C1293 - 08b: Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction

 

Benefits of the Schleibinger ASR machine

• inside 100% stainless steel against corrosion
• bath inside inert gas welded
• perfect insulation to ensure that the temperature outside is not over 30 °C
• free user programmable temperature curves from room temperature up to 80°C
• temperature deviation below 0.5K
• two stainless steel temperature sensors inside up to 4 extra sensors may be connected.
• fulfilling all RILEM and national standards
• graphical colour display showing all temperatures over time.
• SD card inside, and USB memory stick connector outside for registration of all temperatures over time.
• Network and Internet connection for checking all parameters and temperatures remotely, and if the customer likes world-wide!
• two 6 kW heating units with backup functionality (machine can run also with one unit)
• triple overheating protection: mechanical switch, electronically and by software
• contact-less and so wear less switching of the heating unit additional interrupter, if the electronic switch will fault.
• ground fault circuit interrupter for maximum electrical safety
• as option a fog generating system, realizing nearly 100% humidity at 38°C, 40°C, or even at room temperature.
• customer gets a list of all components and necessary spare parts including a complete electrical schematic
• free lifetime software update.
• Schleibinger is not only delivering the machine but also all accessories as the specimen containers, formworks, high precision length measuring gouge made of carbon fiber material, etc.
• the machine is running at very important key units and companies like: 
  
  • VDZ (German Central Cement Research Inst) Düsseldorf, Germany
  • basf Trostberg, Germany
  • University Bochum, Germany
  • IMP Switzerland
  • EMPA (Federal Swiss Material Testing Institute) Zürich, Switzerland
  • BAM (Federal German Materials testing institute) Berlin, Germany
  • Technical University Hamburg, Germany
  • CEMEX Germany
  • USG, USA
  • Erft Labor etc...

 

Literature

• A short presentation about the Schleibinger ASR Reactor
• Website of  Dr. Hempel, Jena, about ASR (in German)
• Important papers from the EU PARTNER Program
• Alkali-Aggregat-Reaktion (AAR) Grundlagen und Massnahmen bei neuen und bestehenden Kunstbauten.
  La réaction alcalis-granulats (RAG) Données de base et mesures des ouvrages d’art nouveaux et existants.
  Swiss paper about ASR (in German and French)
  
• Survey about the US ASR tests.
• Alkali-Silica Reactivity - an exhaustive survey on the WEB site of the US Department of Transportation - Federal Highway Administration
• Experience with ASR test methods: advice on obtaining practical evaluation criteria for performance testing and aggregate testing
  Christoph Müller, Ingmar Borchers, Eberhard Eickschen, Düsseldorf, Germany
• Practical testing of alkali reactivity of concrete compsositions of the WF and WA moisture classes in ASR performance tests
  Ingmars Borchers, Christoph Müller, Dosseldorf
• Alkali Silica Reaction, Minimising the Risk of Damage to Concrete, Guidance Notes and Recommended Practice, (c) Cement and Concrete Association of New Zealand
  (Second Edition incorporating Amendment 1:2012)

• Influence by the cement (VDZ)

   

ASR Specimen Container

for 3 specimen with the size of 75 x 75 x 280 mm.  

Inner size (l x w x h): 280 x 130 x 400 cm. Made of 1.5 mm thick stainless steel, complete welded, pickled and passivated. Lid with drip-down tin. Removable grating for concrete specimen at 50 mm level. Specimen

spacers at 260 mm height. Two handhold's at the length sides. A maximum of 24 containers (in total 72 samples) fit into ASR reactor. Order code K0002.

ASR Fog Generating System with UVC Legionella Protection

For temperatures below 40°C we recommend the additionally power fog system which makes extreme fine fog and nearly 100% rel. humidity also at low water temperatures. With a high pressure pump and special stainless steel nozzles. The size of the droplets is smaller then 30 micron. The fog function may be controlled with the ACR control unit by duration and intensity. Fog power about 1.2 l /hour. Protected against Legionella and similar hazards by an automatic UV-C lamp embedded into the water reservoir. This lamp is only active when both lids are closed. Warranty pump 2 years, nozzles 2 years. Order code K0003.

ASR Mould

for specimen 75x75x280 mm. Made of 10mm thick stainless steel, weight 11 kg. Order code K0113.

ASR Shrinkage Gauge

for measuring the length change of the specimen 280 x 75 x 75 or cylinders 300 x 150mm or similar. There is a socket in the base plate for fixing a 10 mm ball. Including a digital probe. Resolution 0.5 mikron, accuracy 2.6 mikron. Including a carbon made reference bar 280 mm (or 300 mm, others on request) . Order code S0111. 

Reference Anchor for the Specimen

14 mm hexagon bolt, central hole M5 (5mm) with countersink 9 mm x 45°, stainless steel 1.4305. Order code S0115.
Figure below: Anchor-bolts for the specimen

 

 

 

 

Technical Data 

Application	Storing of ACR test containers at 60°C and nearly 100% rel. Humidity according to RILEM/TC-ARP/01/20 and ASTM C1293 and modifies ASTM C1293 at 60°C
Net. size (lxwxh)	1500 x 1100 x 950 mm
Water level	190 mm
Shelfs for the test container	two
Inner cabinet	stainless steel
Lid	2 ca 750 * 120 with torque compensated hinge
Sensors	RTD PT100 1/10 DIN B
Heating	2 x 6 kW 3*230V(or 400V) with over-temperature protection
Controller - heating	2 solid state relays 3 phases
Controller	Remote cabinet for wall mounting
User interface	Colored touch-screen with online graphic
Interfaces	Ethernet /TCP/IP for control and data recording.
Weight	ca. 500 kg
Mains connection	3 * 32 A / 230/400 V, CEE plug (please ask for other voltages and frequencies)

Order codes: 

 

AAR/ASR Tester	K001
AAR Specimen Container	K002
AAR Fog System	K003
AAR mould	K0113
AAR shrinkage gauge	S0111
AAR reference anchor	S0115

 

Resources

Datasheet

User Manual