News
1. New product: MERLIN Bulk Conductivity Tester
The Merlin is one of the newest developments by Germann Instruments. It is used to measure the bulk electrical conductivity, or its inverse, the bulk electrical resistivity, of saturated 100 by 200 mm concrete cylinders or cores.
The test is simple to perform and a test result is obtained within two seconds. The conductivity of a saturated concrete specimen provides information on the resistance of the concrete to penetration of ionic species by diffusion.
Merlin can be used for the following purposes:
| - | Research and development to characterize the influence of new materials on the electrical conductivity of concrete |
| - | Optimizing mixture proportions and supplementary cementitious materials to increase concrete service life |
| - | On-site quality control and quality assurance |
| - | Evaluation of in-place concrete (using cores). |
Download datasheet:
Merlin.pdf
2. New s'MASH system.
Click on the image to enlarge.
New features:
| - | Visual testing grid for instant test overview |
| - | Auto mode for testing at walking speed |
| - | s'MASH connected using USB technology |
A new generation of the s'MASH system has been developed. The system uses a new data acquisitioning board connected by USB instead of the earlier PCMCIA board configuration.
The software contains many new exciting features for immediate evaluation. One of them is the AUTO testing mode which enables the user to test at walking speed. The progress of the testing in the test grid chosen is shown on the laptop screen as illustrated above. The green dots represent already done tests, the yellow the present test location and the red dots unfinished test locations. After a test is done the software automatically change the test position allowing testing to be done very quickly at the same time as an overview in achieved when testing large surfaces.
3. New AVA system.
The new AVA-3000 is featuring:| - | Latest microprocessor technology |
| - | Only one USB cord connection |
| - | Mini balance that can stand rough treatments |
| - | Elimination the influence of external vibration and wind |
| - | Improved stirrer operation |
| - | Incorporates a 35-L temperature water bath tank for automated de-aerating and tempering of the water and the AVA release liquid |
| - | In addition to calculation of the spacing factor and the specific surface for chord length < 2mm (as in the AVA-2000), the AVA-3000 calculates the air-void parameters for cord length < 1mm, as required by the ASTM C 457-06 standard |
The system can be studied in the 'test systems' section "AVA - Air Void Analyzer"
4. New low-cost, portable Rheometer for concrete.
The new ICAR Rheometer features:| - | Portable and lightweight |
| - | Rugged and robust |
| - | Low-cost and versatile |
| - | Fast and accurate |
| - | Automated and simple to use |
| - | Improved description of workability |
| - | Accelerated use of new and cheaper high-performance concrete |
More ICAR Rheometer information can be found in the 'test systems' section "ICAR Rheometer".
5. Introducing the new generation of shear wave instruments.
Three instruments using ultrasound shear waves are now available:
5.1 SURFER for surface wave speed and depth of surface opening cracks
5.2 EyeCon for flaw detection and thickness measurements requiring only one-side access to the structure. Dry contact to the surface, providing 1D and 2D mapping with possibility of 3D images.
5.3 MIRA allowing 3-D tomography of internal defects in colors. Detection of all the classical defects in concrete structures by one-sided access, including air in injected cable ducts. B-, C- and D-Scans are available as well as imaging of layers in the 3D presentation. The MIRA features also wireless connection to the laptop.
The brochures can be downloaded from the 'test systems' section.
6. Impulse Response with the s'MASH.
The s'MASH is for rapid screening of flaws in structures. The parameters tested in structures are the dynamic stiffness and the dynamic mobility of the structure. Color plotting of these two parameters reveal anomalies readily available after the testing has been completed. Areas with anomalies are subsequently scrutinized by e.g. the DOCter Impact-Echo Test and/or by extracting a limited number of cores.Typical applications, as illustrated in the CASE section, are testing for debonding of overlays, voids below slabs, poor consolidation, extent of deterioration from e.g. freeze-thaw, ASR, reinforcement corrosion and fire damage, fastening/anchoring quality of claddings, panels or exterior walls, loss of stress transfer, poor supports, curling of plates and integrity of repairs.
6.1 Slide show of the s'MASH
The presentation used in the one-day course on the s'MASH can be downloaded from the DOWNLOAD section. The slide show outlines the applications, the method, the fundamentals and basics in structure testing, the parameters measured, examples of test output and testing examples.
6.2 New integrated s'MASH and DOCter test system
Germann Instruments has finished the development of an integrated system allowing quick flaw screening to be performed of a structure with the s'MASH Impulse Response System followed up by detailed analysis in areas showing anomalies with the DOCter Impact-Echo Test System. The computer used with attached amplifier unit and PCMCIA card allows both software to be utilized. Additionally is required for the s'MASH Impulse Response Test the instrumented impulse hammer and the geophone, and for the DOCter Impact-Echo Test the Longship transducer unit and the Star Support with attached impactors.
6.3 Latest practical experience with the s'MASH
Papers illustrating the benefits and practicality of the system are available from the DOWNLOAD section. In the latest paper, "Rapid Non-Destructive Test Method at the Taiwan High-Speed Rail Project" by Dr. Allen G.Davis of the CTL Laboratories in Chicago, the s'MASH Impulse Response Test System is illustrated for locating and quantifying deficiencies in post-tensioned box girder concrete such as poor compaction and delamination, as well as loss of post-tensioning caused by patching of partial exposures after post-tensioning and formwork stripping.
6.4 Impulse Response explained theoretically
The paper by N.S.Ottosen, M.Ristinmaa and A.G.Davis: "Theoretical interpretation of Impulse response tests of embedded concrete structures", Div. of Solid Mechanics, Lund University, Lund, Sweden, has been accepted for publication by the American Society of Civil Engineers.
The paper explain by means of analytical modeling typical impulse response field tests stemming from a void and a honeycomb.
7. Impact-Echo with the DOCter.
7.1 New Viking software for the DOCter Impact-Echo Testing
The impact-echo software has been upgraded to version 6.0 accommodating the new 2-channel PCMCIA card used for the testing. This card is also used for the s'MASH Impulse Response Test.
7.2 Testing examples
Presented at the conferences Structural Faults + Repair -2003 in London, U.K. and NDT-CE 2003 in Berlin, Germany, two case studies
| - | "DOCter Impact-Echo Testing for Delaminations in Marine Anchor Blocks" and |
| - | "DOCter Impact-Echo Testing of Steel Cable Ducts for Voids" |
8. Air Void Analysis of fresh concrete by the AVA.
The AVA allows the concrete practitioner to measure the air void spacing factor and specific surface of the fresh concrete in about half an hour, providing timely information of these important parameters for evaluation of the freeze-thaw durability of the concrete.8.1 New excellent video on the AVA.
This video named "Real Air Testing in Real Time" produced by the U.S. Kansas Department of Transportation (KDOT) describes the relationship between durability and the spacing of air voids, it shows an AVA testing example from paving, the detailed operation of the AVA and outlines the benefits of the AVA compared to the traditional methods for measuring the total air content of fresh concrete as well as the ASTM C 457 linear traverse method for the air void structure on hardened concrete.
The video can be obtained from Germann Instruments upon request.
8.2 The FHWA experience with the AVA.
The paper "A "Fresh" Perspective on Measuring Air in Concrete" discusses Federal Highway Administrationīs (FHWA) recent experience with the AVA. FHWA has employed the use of the AVA on numerous bridge and pavement projects throughout the United States with encouraging results. The paper by G.L.Crawford, L.G.Wathne and J.I.Mullarky can be downloaded from the DOWNLOAD section.
8.3 Presentation of the AVA by the AASHTO TIG (American Association of State Highway and Transportation Officials, Technology Implementation Group)
This very comprehensive presentation of the AVA can be downloaded from the DOWNLOAD section. Further information can be found on www.aashtotig.org
The presentation discuss why the entrained air in concrete should be measured, why a specific distribution of the air voids is needed, freeze/thaw damages experienced in the U.S., the necessary and sufficient conditions for obtaining such freeze/thaw damages, durability related to the spacing factor, methodologies for testing, purpose of the AVA, current U.S. practice, U.S. experience with the AVA, recommendations, how to improve the spacing factor, AVA advantages and limitations, benefits and the costs involved.
9. Timing of early loading operation with the LOK-TEST.
The LOK-TEST is gaining acceptance as a reliable means of measuring the compressive strength of early age concrete, not only in North America, but also in Europe, especially in the U.K.9.1 LOK-TEST presentation.
A power point presentation of the LOK-TEST has recently been made available. The presentation can be downloaded from the DOWNLOAD section or obtained from Germann Instruments.
9.2 New publications on LOK-TEST.
Three new publications dealing with LOK-TEST are now available from the U.K.:
| - | "Early age acceptance of concrete (Improved quality mangament) by J.H.Bungey, A.E.Long, M.N.Soutsos and G.D.Henderson, BRE (British Research Establishment) report 387, published by CRC Ltd. |
| - | "Early age strength assessment of concrete on site", in the series of Best Practice Guides for In-Situ Concrete Frame Buildings, BCA, BRE, Construct, Reinforced Concrete Counsil and DETR, ISBN 0 7210 1554 9, published by British Cement Association, Century House, Telford Avenue, Crowthorne, Berhshire RG45 6YS, U.K. (can be obtained from the Concrete Bookshop, Phone +44 (0)1344 725704) |
| - | "Guide to Flat Slab Formwork and Falsework", ISBN 0 046691 90 8, Order Reference CS 140, CONSTRUCT Concrete Structures Group 2003, Published by The Concrete Society on behalf of CONSTRUCT, The Concrete Society, Century House, Telford Avenue, Crowthorne, Berkshire RG45 6YS, U.K. (Phone +44 (0)1344 466007, Email: enquiries@concrete.org.uk, www.concrete.org.uk |
10. Corrosion investigation with the GalvaPulse.
10.1 Recent modifications of the GalvaPulse
The GalvaPulse for corrosion rate, half-cell potentials and electrical resistance has recently been modified to be able to operate in one of two modes:
| - | Only half-cell potentials and electrical resistance |
| - | All three measurements (corrosion rate, half-cell potentials and electrical resistance), |
In the first mode each measurement can be made as fast as the physical movement allows. In the second mode the corrosion rate measurement last 5-10 seconds.
In this manner the GalvaPulse can be applied quickly in large jobs in the first mode for a general overview of the corrosion condition, followed up by detailed analysis in hot-spot areas, where the corrosion rate is needed.
Furthermore, the GalvaPulse hand-held computer has been supplied with a FLASH card that allows reinstallation of the software should it be lost due to simultaneous removal of the main batteries and the back-up battery.
10.2 New information on the GalvaPulse
In addition to the earlier publications on the GalvaPulse listed in the DOWNLOAD section, the following paper is now also available:
"Pro's and Con's of half-cell potentials and corrosion rate measurements" by T.Frolund, O.Klinghofer and H.E.Sorensen, Force Technology, Brondby, Denmark.
The paper can be downloaded from the DOWNLOAD section.