Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods.

Acoustic emission (AE) technique is used for monitoring and evaluating the influence of corrosion on the structural behaviour of steel reinforced concrete (RC) beams under three-point flexure test. In this study, steel corrosion was accelerated by electro-chemical method utilising a direct current (DC) power supply and 5% sodium chloride (NaCl) solution. The steel corrosion that was induced into beam specimens casting were estimated at 0%, 4.55% and 32.37%, respectively, according to mass loss of steel reinforcement. Based on observations during static load test, the damage developed in the specimens could be classified into four different stages, namely, micro-cracking, first visible cracks, cracks distribution, as well as damage localization and yielding. Analysis of the AE data reveals distinguishable trends for RA value and average frequency (AF) registered for different corrosion levels, respectively. Moreover, the index of damage (ID) derived from the AE energy parameters obtained during the first stage of damage was found to be useful as an indicator for evaluating the extent of corrosion damage of RC beam specimens at initial loadings. In addition, to provide a practical application of AE toward life span estimation of corroded beam specimen, a Weibull damage function was introduced to estimate the remaining flexural capacity of the beam specimens. Based on analysis as well, it is noted that tensile fracture became more dominant with an increase in corrosion level.

Corrosion of steel reinforcement is a major cause of structural damage that requires repair or replacement. Early detection of steel corrosion can limit the extent of necessary repairs or replacements and costs associated with the rehabilitation works. The ground penetrating radar (GPR) method has been found to be a useful method for evaluating reinforcement corrosion in existing concrete structures. In this paper, GPR was utilized to assess corrosion of steel reinforcement in a concrete slab. A technique for accelerating reinforcement bar corrosion using direct current (DC) power supply with 5% sodium chloride (NaCl) solution was used to induce corrosion to embedded reinforcement bars (rebars) in this concrete slab. A 2 GHz GPR was used to assess the corrosion of the rebars. The analysis of the results of the GPR data obtained shows that corrosion of the rebars could be effectively localized and assessed.

Abstract-The applicability and reliability of Infrared (IR) spectroscopy to distinguish normal and abnormal cells has opened this research to obtain new features from IR spectral of cervical cells to be fed into multilayered perceptrons (MLP) networks. In order for neural networks to be used as cervical precancerous diagnostic system, the features of cervical cell were used as inputs for neural networks and the classification of cervical cell types were used as output target. For cervical cell classification, this study proposes new features of cervical cell spectrum that are suitable and can be used as inputs for neural networks. The new cervical cell features were extracted from ThinPrep® spectrum and their applicability were tested by using seven types of MLP training algorithm. The MLP network trained using Levenberg-Marquardt Backpropogation (trainlm) algorithm presented the highest accuracy with percentage of 97.3%. The result shows that the proposed features i.e. area under spectrum at 1800-1500 cm -1 , area under spectrum at 1200-1000 cm -1 , area under spectrum at 1800-950 cm -1 , height of slope at 1650-1550 cm -1 , corrected area of protein band at 1590-1490 cm -1 , corrected area of glycogen band at 1134-985 cm -1 , corrected peak height protein (H1545) and corrected peak height glycogen (H1045) are applicable to be fed as input to neural network for cervical spectra classification in cervical precancerous diagnostic system.

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The steel corrosion of concrete structures has been one of the primary causes of structural degradation. Early identification of the steel corrosion might help minimize the location and the duration of the repair required and the cost associated with restoration work. The acoustic emission (AE) technique is more effective for assessing the corrosion of the steel reinforcement in the concrete structures. The AE technique successfully monitors and analyses energy signals released from the crack of the concrete matrix by the corrosion activity using AE sensors placed on the concrete surfaces. The main objective of this research is to assess the flexural behaviour of the corroded concrete beam specimens under the loading test using the AE technique. Three concrete beams were performed for the evaluation of corroded concrete beam specimens using the AE technique. During the experiments, the corroded beam specimens were flexural loaded together with data acquisition by the AE technique. The data obtained were processed, and AE parametric-based analysis was carried out. The AE technique was successfully conducted for fracture monitoring of the corroded beam specimen under flexure load. The AE parameters include the AE hits, and the Ib-value of the AE data was successfully introduced to assess the flexure behaviour of the corroded concrete beam specimens. It can be found that fluctuation follows a rising pattern in the Ib-value and then a declining trend in the Ib value. The lowest Ib-value exists at the damage stage IV for all beam specimens except the HC beam specimen. The lowest Ib-value occurs at the beginning of the damage stage III for the HC beam specimen.

Sering kali kita mendengar istilah ramah difabel dilekatkan pada berbagai sarana prasarana maupun layanan publik. Sehingga sering kali pula kita jumpai istilah puskesmas ramah difabel, sekolah atau kampus ramah difabel, kantor pemerintah ramah difabel, dan sebagainya. Salah satu ciri kampus ramah difabel adalah terbukanya dengan luas akses belajar dengan baik, misalnya, tersedianya jalur pedestrian dengan guiding block, ramp (jalan miring) untuk masuk ke sebuah gedung, adanya tangga dengan pegangan tangan (hand-rail), lift dengan tombol huruf braille, dan toilet khusus difabel di setiap gedung. Syarat-syarat mengenai sarana prasarana ramah difabel secara detail telah diatur pada Peraturan Menteri Pekerjaan Umum dan Perumahan Rakyat (PermenPUPR) Republik Indonesia No 14 Tahun 2017. Untuk membangun aksesbilitas yang prioritas bagi mahasiswa difabel UMY akan dilaksanakan beberapa kegiatan seperti survei untuk pendataan mahasiswa difabel Universitas Muhammadiyah Yogyakarta (UMY), diikuti dengan seminar, dan dilanjutkan dengan evaluasi dan sarana prasarana untuk aksesbilitas mahasiswa difabel UMY melalui survei lapangan. Melalui survei tersebut, Gedung kembar AR Fachruddin UMY memang sudah mempunyai akses jalan miring, tangga dengan hand-rail, dan lift dengan tombol huruf braille, namun belum memiliki toilet khusus difabel yang sesuai standar untuk mereka yang mempunyai kebutuhan khusus sesuai PermenPUPR No 14 Tahun 2017 tersebut. Survei juga dilakukan pad Gedung Admisi, Gedung Siti Walida F3, serta jalur pedestrian antara Gedung AR Fachruddin, Gedung Admisi, dan Gedung Siti Walida.

Corrosion of steel reinforcement in the reinforced concrete (RC) members contribute to structural damage and failure. This study proposes a damage classification method for corroded reinforced concrete (RC) beams subjected to flexural loading by linear discriminant analysis (LDA) of acoustic emission (AE) data. The structural behavior of RC beam specimens induced with varying steel corrosion levels was evaluated by AE monitoring during the flexural load test. Analysis of primary AE data, RA value (ratio of rise time to amplitude of the waveforms) could be correlated and used to classify the fracture type. It was found that the proposed LDA could achieve good accuracy in damage classification of corroded RC beams.