scholarly journals Diagnosing in Situ Concrete by Some Non-Destructive Test Methods

1994 ◽  
Vol 5 (1) ◽  
pp. 15-22
Author(s):  
Shoji Amasaki ◽  
Kazuhiro Kuzume ◽  
Toyoaki Miyagawa
2014 ◽  
Vol 605 ◽  
pp. 194-197
Author(s):  
Seung Hun Kim ◽  
Seong Uk Hong ◽  
Yong Taeg Lee ◽  
Seung Ho Lee

In order to maintain the existing concrete structures in a safe and usable state, an overall maintenance management is necessary regarding structure aging from quality management of new construction. Thus, non-destructive testing is needed to estimate the structure damage, defect, or proper construction without damaging the structure. In U.S., there is a standard for non-destructive test (ACI 228.2R-98), and also in Japan, the non-destructive test method and compressive strength estimation manual was prepared by the Architectural Institute of Japan in 1983, and there are active researches in the ground field, but it lacks verification in architecture field. Thus, in this study, a technique that can estimate the depth of concrete column member using the Impact Echo method which is one of the non-destructive test methods shall be reviewed and evaluated for applicability to the architecture field. The specimen was mixed with design strength of 30MPa. The equipment used in testing is Freedom Date Pc Platform Win.TFS 2.5.2 by company Olson of U.S., and the experiment involved leveling the top surface of the concrete member, installing the equipment and applying impact 9 times, and taking the average of the reverberation values obtained. The estimated average depth of concrete column member using Impact Echo method was 304mm for IEC-300, 398mm for IEC-400, and 484mm for IEC-500, and the relative error rate compared to the actual size was 1%~3%. Through this study, the applicability of estimation of depth in concrete column members using impact echo method could be confirmed.


2008 ◽  
Vol 8 (3) ◽  
pp. 120
Author(s):  
Supriadi Supriadi

<p>Application of standard for remaining life assessment at boiler tube of steam powered electrical generator unit by<br />non-destructive test (NDT), up to now has been very important. The condition of boiler tube used in electrical<br />generator in Indonesia has reached its design limit and even some of them have replaced. This research used nondestructive<br />test methods by SNI, JIS and API standard and was conducted at boiler unit II in Indonesia, that has<br />already in 25 years operated. This method consists of several technique approaches that are: replica methods<br />(microstructure), hardness test, outside diameter measurement (OD), and wall thickness measurement. After<br />assessment and analysis, the results of non destructive test methods showed that the remaining life of boiler tube<br />is 100.000 to 120.000 operation hours.</p>


Author(s):  
Zsuzsanna Kósa ◽  
Ákos Török

Construction materials of a partly ruined Medieval church of Central Hungary were studied in details to assess its conditions and to obtain information on the phases of construction. At first, digital images were taken to create a 3D model of the remaining walls. The material properties were measured in situ using non-destructive test methods. Strength parameters of stone and render were assessed by Schmidt hammer, while moisture content was measured by a portable moisture meter. According to lithological descriptions and thin-section analyses limestone prevail in the monument. The most common Miocene limestone is represented by various lithologies, such as cemented macro porous limestone, fine-grained porous limestone, oolitic limestone and bioclastic limestone. Mesozoic micritic well cemented limestone and Tertiary limonitic sandstone were also identified at the ruins. The most common weathering forms are selective dissolution, multiple flaking and biological colonisation. Renders used in the structure represents the long history of the structure from Medieval lime-based mortars to Portland cement containing latest applications. The former one is composed of quartz send in lime binder. According to Schmidt hammer tests, the rebound values of the replacement stone is higher than that of the original porous limestone. There is a distinct difference in the moisture content of the stone and render. Orientation/exposure of the wall also influences the moisture content. The gathered information allows for designing better repair methods and helps in the planning of the maintenance of the medieval stone heritage.


Author(s):  
Pradeep Lall ◽  
Nakul Kothari ◽  
John Deep

Field extracted electrical assemblies, subjected to harsh environments including storage, and transportation may have often sustained degradation in their material properties and physical structure, without exhibiting external signs of damage. The lack of macro-indicators of damage makes the quantification of sustained damage and the remaining useful life challenging for assessment of the reliability makes quantification of accrued damage and remaining useful life much difficult. The operation environment requires survivability under high-g loads often in excess of 10,000g-100,000g. The need of non-destructive test methods for determination of the internal damage and the assessment of expected operational reliability under the presence of accrued damage from prolonged storage is extremely desirable. While a number of non-destructive test methods such as x-ray, and acoustic imaging exist in the state-of-art — they are limited to the acquisition of imaging of the internal damage state without the ability of conducting measurement of deformation under the action of environment loads. There is scarcity of literature on studying progressive damage to the physical structure of fuze components when subjected to high g shocks. Previously, researchers have studied the reliability of fuze subjected to high-temperature and high-g mechanical shocks, measured redundancy and reliability of fuze electronics through prediction of failure rates and MTTF using MIL-HDBK-217F standard, and performed on fault diagnosis. In this paper, a full-field deformation measurement technique has been presented to monitor damage in key components of the fuze after exposure to multiple high G shocks. Fuze assembly has been subjected to 30,000g mechanical shock until failure. The fuze assembly is CT scanned at regular intervals and the scan data is compared to the pristine scan data to compute physical deformations and damage sustained during the mechanical shock event.


2012 ◽  
Vol 23 (3-4) ◽  
pp. 989-997
Author(s):  
Serdal Terzi ◽  
Mustafa Karaşahin ◽  
Süleyman Gökova ◽  
Mustafa Tahta ◽  
Nihat Morova ◽  
...  

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