{"title":"Assessment of multi-hazards affecting service life of existing reinforced concrete (RC) bridges of Barak valley region, Assam, India","authors":"Joydeep Das, Arjun Sil","doi":"10.1080/24705314.2020.1783123","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783123","url":null,"abstract":"ABSTRACT The probabilistic approach for estimating deterioration of existing RC bridges due to multiple hazards becomes an important subject for the bridge management system. In the present study, a multi-hazard approach as well as investigation proposed to assess how service life of the bridges affected due to the amalgamation of the physical deterioration (aging) along with earthquake hazards. In this approach, the Weibull distribution is found suitable and employed for determining deterioration in terms of hazard function ha(t) of the bridges due to aging. Conversely, the northeast (NE) region of India is highly tectonically active and prone to earthquakes of higher magnitude (Mw>8). Considering the high seismicity in the study region, respective active faults and their corresponding maximum PGA values are taken into account to evaluate the earthquake hazard of the region in a site specific manner. By applying this proposed approach, significant site specific in-depth ideas and facts about their service life span could be evaluated considering the condition of existing bridges for satisfactory performance that would be helpful in taking rational decisions for the bridge management system (BMS) in terms of safety, rehabilitation, repair and inspection strategies of the bridges available in the study region for sustainable growth.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"223 - 235"},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43404848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Keshav K. Sharma, A. Imam, F. Anifowose, Vikas Srivastava
{"title":"Compressive strength modeling of blended concrete based on empirical and artificial neural network techniques","authors":"Keshav K. Sharma, A. Imam, F. Anifowose, Vikas Srivastava","doi":"10.1080/24705314.2020.1783120","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783120","url":null,"abstract":"ABSTRACT This article exhibits an experimental study carried out to investigate the combined effect of Silica Fume (SF) and Metakaolin (MK) on the fresh and hardened properties of concrete. The replacement levels of SF were adopted as 5%, 10%, 15%, 20% while that of MK were 5%, 10%, 15%, 20% and 25%. The results for cube testing revealed that the use of SF and MK produces considerably good strength concrete. Based on the experimental observations, an approach to predict the compressive strength using regression modeling was suggested. The result of which rendered a reasonable agreement with the available test data. Moreover, two Artificial Neural Network (ANN) models have also been proposed to predict the compressive strength of concrete using the data obtained from the experimental exercise. Randomized stratification method was used to divide the data samples into training and testing subsets in line with machine learning best practices. The results of the ANN models were found to be in good agreement with experimental values. When compared with the results of empirical models, the respective ANN models gave a better prediction for the compressive strength. This substantiates the reliability of ANN over the empirical models.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"252 - 264"},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43572440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyeongi Lee, A. Hanif, M. Usman, Younghwan Kim, H. Oh, Seong-Kyum Kim
{"title":"Interfacial characteristics of cement mortars containing aggregate derived from industrial slag waste","authors":"Hyeongi Lee, A. Hanif, M. Usman, Younghwan Kim, H. Oh, Seong-Kyum Kim","doi":"10.1080/24705314.2020.1783124","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783124","url":null,"abstract":"ABSTRACT In this study, porosity assessment of cement mortars containing Precious Slag (PS) Ball – an industrial waste produced by rapid cooling of slag generated from steel making process by Slag Atomizing Technology – is done by Back-Scattered Electron (BSE) image analysis. PS incorporated mortars were fabricated and subsequently evaluated for compressive strength. BSE images were analyzed by pore segmentation method. Binarization on the images using Otsu’s thresholding method was done followed by the porosity determination. As the interfacial attributes were the primary concern, the porosity was determined from the aggregate surface to the 100 μm width. A total of 24 sections were analyzed and the mean values were plotted. Although the PS Ball incorporated mortar exhibited 10% lower strength at 28-day age, it showed stronger and less porous aggregate- matrix interface between (from particle surface up to 35 μm width) as compared to that of normal mortar containing sand, which is justifiable by the chemical composition of PS Ball attributed to the potential chemical binding. Further, the porosity decreased as the distance from aggregate surface increased. While the use of PS Ball is environmentally friendly, its enhanced interfacial properties with some strength loss of resulting cement mortars encourages its use in sustainable construction materials.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"236 - 243"},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47010067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bending strength diagnosis for corroded reinforced concrete beams with attendance of deterministic, random and fuzzy parameters","authors":"Thanh-Hung Nguyen, A. Le, D. Nguyen","doi":"10.1080/24705314.2020.1765268","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765268","url":null,"abstract":"ABSTRACT The concrete reinforced beams, especially in coastal zones, usually show the signs of degradation due to the steel reinforcement corrosion after a period of serving. It causes the strength of the concrete reinforced structures decreasing. Remaining strength of corroded reinforced structures is needed to assess in a specific time. However, it is not easy to have all input data for assessing the service life of reinforced concrete structures because many parameters have been also changed along with the corrosion of steel reinforcements. An algorithm is developed for forecasting the strength remains of the beams in which the reinforcement corrosion is considered. The reinforcement corrosion is assumed as effecting on the diameter of steel bars and the bond between steel bar and concrete. In case of incomplete data, statistical analysis of the corrosion percentage was conducted using Monte Carlo simulations. The results of the algorithm are verified with the published results.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"183 - 189"},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765268","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48441161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Memon, Muhammad Zain, Dichuan Zhang, Sardar Kashif Ur Rehman, M. Usman, Deuckhang Lee
{"title":"Emerging trends in the growth of structural systems for tall buildings","authors":"S. Memon, Muhammad Zain, Dichuan Zhang, Sardar Kashif Ur Rehman, M. Usman, Deuckhang Lee","doi":"10.1080/24705314.2020.1765270","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765270","url":null,"abstract":"ABSTRACT Tall buildings are being built for more than a century now, but there has been an exponential growth in the development of convoluted tall buildings with distinctive architecture. A tall building with a unique structural form, brings forth admonishing challenges for the structural designers to deal with. Such a contemporary inclination towards the fabrication of free-form structures has posed enormous challenges to the modern-day structural engineering community, and consequently, has faced reactions in the form of tremendous researches pertaining to complex building specific issues. This paper extensively reviews six case studies of recent tall buildings that possess a challenging architecture with tortuous structural features to cope with the gravity and lateral loadings. Six representative tall buildings have been chosen from all over the world, which have distinctive features in terms of their structural systems. This paper discusses the fundamental characteristics of these tall buildings in the world and presents the challenges faced during the modelling, analysis, design, and construction of these skyscrapers, along with the brief of methodologies which were eventually adopted to cope with these challenges.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"155 - 170"},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47070698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of a hydraulically controlled conveyor belt clamp for heavy-duty drift belt installation in underground applications: a case study","authors":"G. Wheatley","doi":"10.1080/24705314.2020.1765267","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765267","url":null,"abstract":"ABSTRACT The following paper provides a summary of the design and operating parameters for the Dynamic Belt Clamp. The Dynamic Clamp is hydraulically controlled to apply braking force on a belt via reference from an operator input. Belt braking force is proportional to hydraulic pressure applied. The clamp is not designed to be “fail safe” with the clamp opening when hydraulic system pressure is lost. Hand calculations were used along with finite element analysis to determine the structural stresses induced by the combined clamping force and belt tension. A 20 Metric Tonne belt tension capacity (196.1 kN lateral load) has been nominated for design purposes. A belt thickness of 50 mm has been assumed as a worst case for design purposes. In addition, a dynamic coefficient of friction of 0.2 has been assumed for the contact surfaces between the belt and the clamping beam surfaces. Australian Standard AS1418.1 – Cranes, Hoists and Winches General and AS3990 Mechanical Equipment – Steelwork have been utilized for determining the suitability of the design. The design meets the requirements of the standards for the proposed clamping loads and belt tensions. The combined stresses do not exceed allowable stress or displacement recommendations.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"171 - 182"},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765267","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42490791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Health assessment based on dynamic characteristics of reinforced concrete beam using realtime wireless structural health monitoring sensor","authors":"A. Danish, Faran Tayyab, M. U. Salim","doi":"10.1080/24705314.2020.1765271","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765271","url":null,"abstract":"ABSTRACT The uses of dynamic estimations on existing structures are numerous: evaluation of their seismic vulnerability, structure’s abilities in post-quake circumstances or after changes in the region, and so on. At present, this sort of estimation enables auxiliary conclusion on a global scale, while the identification and the assessment of local damage (each element of the structure) needs to be investigated. Additionally, we begin to co-exist and interact with smart interconnected devices known as the Internet of Things (IoT). The IoT brought new opportunities for our society. Yet, most of the existing Structural Health Monitoring (SHM) systems are not connected to the IoT. Hence, this article studies the integration of complete real-time SHM platform with the Iot system, which can provide structural health of a structure and the performance of this sensor was check on a reinforced concrete (RC) beam. The RC beam was loaded in the central part in several stages corresponding to different damage states. Displacements were measured simultaneously using displacement sensors. After each load/unload cycle, dynamic measurements were taken using accelerometers. The perceptions from investigation were displayed, with the presence of damage and the reduction in natural frequencies that occurred in conjunction with reduction in stiffness.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"204 - 210"},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765271","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41531459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of cementing efficiency factor on the mechanical properties of concrete incorporating silica fume","authors":"Rahul Biswas, B. Rai","doi":"10.1080/24705314.2020.1765269","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765269","url":null,"abstract":"ABSTRACT Silica fume is a recognized pozzolan which can contribute unique properties to Portland cement products. The use of silica fume in cement and concrete technology has unexpectedly increased over the most recent couple of years with the advent of high-performance concrete. All the previous researches in estimating the cementing efficiency factor of silica fume have been built on the strength prediction of concrete at different w/c ratio for different percentage replacement of silica fume. In the present work, the cementing efficiency factor for silica fume at different percentage replacement level has been assumed, and at the constant water to binder ratio, the compressive strength has been obtained. Further, the results of 28-day compressive strengths of silica fume concrete have been examined using a response surface model and a relationship has been projected. This model, which relates compressive strength with water to binder ratio, cementing efficiency factor and percentage silica fume, might find a useful application in the strength prediction of silica fume concretes.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"190 - 203"},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48737758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deterministic deterioration modeling of wind turbines toward the failure identification – a modal curvature approach","authors":"Yung-Chiang Lin, C. Chiang, Chih-Peng Yu, K. Hsu","doi":"10.1080/24705314.2020.1729518","DOIUrl":"https://doi.org/10.1080/24705314.2020.1729518","url":null,"abstract":"ABSTRACT The amount of built wind resource has greatly increased since wind turbines have started to get installed offshore in order to power much of the world. Topics relating to wind turbine have encouraged researchers to put in greater efforts towards developing modeling methodologies, analytical theories, assessment techniques. Through the establishment of certain models and new findings, potential ideas regarding structural health monitoring and non-destructive evaluations may be proposed and worthy of exploration. Based on the spectral formulation of a Timoshenko member with the consideration of soil–structure interaction, the simulated model of a wind turbine was investigated in this work in order to quantify the various effects due to defects as well as foundation stiffness on the dynamic responses of the tower. This paper focuses on the analysis of the tower structure using the modal curvature data of the first vibration mode. Preliminary results show that the curvature index defined in the proposed method is capable of indicating not only the damaged region of the tower, but also the degree of stiffness softening that the foundation system may have encountered. The presented methodology demonstrates potential as a feasible analysis method to be applied in a vibration-based assessment scheme for the wind turbine tower.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"104 - 112"},"PeriodicalIF":2.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1729518","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42261774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A data-driven probabilistic model for well integrity management: case study and model calibration for the Danish sector of North Sea","authors":"S. Miraglia","doi":"10.1080/24705314.2020.1746013","DOIUrl":"https://doi.org/10.1080/24705314.2020.1746013","url":null,"abstract":"ABSTRACT The correct functioning of well completion in oil and gas facilities is eminently important to assure continuity of production operations together with an adequate safety level. To enhance the performance of production wells and reduce maintenance expenditures, a paradigm shift from corrective maintenance to proactive risk based maintenance is necessary. The feasibility of fully probabilistic risk-based inspection planning approach for oil wells has been investigated as pilot study carried out at Danish Hydrocarbon Research and Technology Centre (DHRTC). After establishing a baseline for the system taxonomy, failure modes and their dependencies on deterioration mechanisms, a data collection and analysis lead to the calibration of a corrosion probabilistic model, based on pit size measured from tubing inspections. This manuscript presents the results of the feasibility study, the calibration of a bespoke corrosion model for wells in the Danish sector of North Sea, the reliability analysis and the identification of a threshold value for the pit penetration to be compared with current oil & gas (O&G) regulations. The model is further used to compare expected maintenance costs for corrective maintenance and condition-based maintenance. Results show how the condition-based maintenance policy results in lower maintenance costs and potential extension of well lifetime.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":"5 1","pages":"142 - 153"},"PeriodicalIF":2.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1746013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47096545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}