scholarly journals IDENTIFIKASI DEGRADASI MUTU BETON PADA STRUKTUR BANGUNAN GEDUNG DI JAKARTA

Author(s):  
Henny Wiyanto

Concrete quality degradation is a concrete quality downgrade from the perspective of concrete tension. Concrete quality degradation on concrete structure can happen either on new buildings (buildings that are still being constructed/in construction phase) or existing buildings (buildings that are already operational/in operational phase). The possible causes of concrete quality degradation on new buildings are, among others: incorrect implementation process such as readymix concrete quality that isn’t according to plan, lack of compacting, inadequate maintenance. Concrete quality degradation examination is done by examining concrete tension. On new buildings, one of the ways concrete tension can be identified is through test object examination. Concrete is a construction material that has a unique tension trait, where if it’s examined with a number of test objects, the value will spread around one particular average value. The value number depends on the field implementation perfection level. If the concrete tension of test object isn’t according to plan, installed concrete assessment with destructive and non destructive method can be performed. This research is done to identify the amount of concrete quality degradation on building structure based on tension value of concrete test object at the construction phase. Analysis results show the occurrence of a large concrete quality degradation, necessitating the determination of characteristics and categories until the worst possible concrete condition for concrete condition assessment needs.  AbstrakDegradasi mutu beton adalah penurunan kualitas beton dilihat dari kuat tekan beton. Degradasi mutu beton pada struktur beton dapat terjadi baik pada bangunan baru (bangunan yang sedang dibangun/tahap konstruksi) maupun bangunan existing (bangunan yang sudah beroperasi/tahap operasional). Penyebab degradasi mutu beton pada bangunan baru diantaranya ada bagian pada proses pelaksanaan yang kurang tepat seperti mutu beton readymix tidak sesuai rencana, kurangnya pemadatan, perawatan beton kurang baik. Pemeriksaan degradasi mutu beton dilakukan dengan memeriksa kuat tekan beton. Pada bangunan baru, kuat tekan beton dapat diketahui salah satunya melalui pengujian benda uji. Beton adalah suatu bahan konstruksi yang mempunyai sifat kekuatan tekan yang khas, yaitu apabila diperiksa dengan sejumlah besar benda uji, nilainya akan menyebar sekitar suatu nilai rata-rata tertentu. Besar atau kecil nilai bergantung pada tingkat kesempurnaan pelaksanaan di lapangan. Apabila kuat tekan beton dari benda uji tidak sesuai rencana maka dapat dilakukan pengujian beton terpasang dengan metode non destruktif dan destruktif.  Penelitian ini dilakukan untuk mengetahui besarnya degradasi mutu beton pada struktur bangunan gedung bertingkat berdasarkan nilai kekuatan tekan benda uji beton pada tahap konstruksi. Hasil analisis menunjukkan terjadi degradasi mutu beton yang besar, sehingga perlu ditetapkan karakteristik dan kategori sampai kondisi beton terburuk untuk kebutuhan penilaian kondisi beton.

1983 ◽  
Vol 27 ◽  
Author(s):  
L. Salamanca-Riba ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
T. Venkatesan

ABSTRACTRutherford backscattering spectrometry (RBS) is used to characterize the stoichiometry of graphite intercalation compounds (GIC). Specific application is made to several stages of different donor and acceptor compounds and to commensurate and incommensurate intercalants. A deviation from the theoretical stoichiometry is measured for most of the compounds using this non-destructive method. Within experimental error, the RBS results agree with those obtained from analysis of the (00ℓ) x-ray diffractograms and weight uptake measurements on the same samples.


Author(s):  
Prong Kongsubto ◽  
Sirarat Kongwudthiti

Abstract Organic solderability preservatives (OSPs) pad is one of the pad finishing technologies where Cu pad is coated with a thin film of an organic material to protect Cu from oxidation during storage and many processes in IC manufacturing. Thickness of OSP film is a critical factor that we have to consider and control in order to achieve desirable joint strength. Until now, no non-destructive technique has been proposed to measure OSP thickness on substrate. This paper reports about the development of EDS technique for estimating OSP thickness, starting with determination of the EDS parameter followed by establishing the correlation between C/Cu ratio and OSP thickness and, finally, evaluating the accuracy of the EDS technique for OSP thickness measurement. EDS quantitative analysis was proved that it can be utilized for OSP thickness estimation.


2018 ◽  
pp. 44-47
Author(s):  
F.J. Тurayev

In this paper, mathematical model of nonlinear vibration problems with fluid flows through pipelines have been developed. Using the Bubnov–Galerkin method for the boundary conditions, the resulting nonlinear integro-differential equations with partial derivatives are reduced to solving systems of nonlinear ordinary integro-differential equations with both constant and variable coefficients as functions of time.A system of algebraic equations is obtained according to numerical method for the unknowns. The influence of the singularity of heredity kernels on the vibrations of structures possessing viscoelastic properties is numerically investigated.It was found that the determination of the effect of viscoelastic properties of the construction material on vibrations of the pipeline with a flowing liquid requires applying weakly singular hereditary kernels with an Abel type singularity.


1968 ◽  
Vol 51 (4) ◽  
pp. 752-755
Author(s):  
Edward L Pratt ◽  
Morris E Auerbach

Abstract Raceophenidol in feed at concentration levels intended for growth promotion of poultry can be estimated by a curvature inversion measurement related to the ultraviolet spectrum of derived p-methylsulfonylbenzaldehyde. The drug can be accurately measured at the 0.0005% level. Collaborative studies on the method showed an average value of 94 ± 10% of claim. The method is recommended for adoption as official, first action.


2015 ◽  
Vol 72 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Marko Igic ◽  
Nebojsa Krunic ◽  
Ljiljana Aleksov ◽  
Milena Kostic ◽  
Aleksandra Igic ◽  
...  

Background/Aim. The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals ?O? and ?E? with the control of values o btained by applying cognitive functions. Methods. This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words ?OLO? and ?ELE?. Checking the correctness of the particular value for the word ?OLO? was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values i n determining the vertical dimension of occlusion and the ?OLO? and ?ELE? in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. Results. The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word ?OLO? for the entire sample was 5.51 mm and for the word ?ELE? for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, ?ELE? and ?OLO?. There was a statistically significant difference between the values f or the vertical dimension at rest, ?OLO? and ?ELE? for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, ?OLO? and ?ELE?, for both groups of subjects. Conclusion. Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word ?OLO? or 7.5 mm in pronunciation of the word ?ELE?.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 18
Author(s):  
Rahel Jedamski ◽  
Jérémy Epp

Non-destructive determination of workpiece properties after heat treatment is of great interest in the context of quality control in production but also for prevention of damage in subsequent grinding process. Micromagnetic methods offer good possibilities, but must first be calibrated with reference analyses on known states. This work compares the accuracy and reliability of different calibration methods for non-destructive evaluation of carburizing depth and surface hardness of carburized steel. Linear regression analysis is used in comparison with new methods based on artificial neural networks. The comparison shows a slight advantage of neural network method and potential for further optimization of both approaches. The quality of the results can be influenced, among others, by the number of teaching steps for the neural network, whereas more teaching steps does not always lead to an improvement of accuracy for conditions not included in the initial calibration.


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