Journal des structures en acier et de la construction

Kashmir lies in region where temperature in winter is very low. The temperature in Kashmir is often below 0°C during couple of months winter. Concrete mixed, transported and placed under low temperatures requires an understanding for the adverse effects of such environmental factors on the durability of concrete. The damage caused by extreme weather conditions can never be fully eliminated but efforts can be made to minimize these adverse effects. This research was undertaken to investigate the effects of Extreme weather on different properties of concrete and influence of early temperature on the strength of concrete. Three temperatures, two 5°C and one 25°C were selected and maintained for the first three days for freshly prepared concrete and during the early hardening state of concrete. After three days all the samples were cured at room temperature. The most common traditional mix of 1:2:4 was selected for the research work because it is used for maximum construction projects. Admixtures Sodium Nitrite was used to see useful effects of these during extreme weather conditions. After the conduct of research, it has been concluded that cold wheather concreting has serious effect on different properties of concrete, like strength, workability and rate of hardening, during the early hardening state.To eliminate the ill effects, it is the duty of the designer/engineer to plan in advance the selection of materials, types quality and quantity of admixtures and coordination of all phases of work so that conreting can be done safely without damage from freezing throughout the winter months in cold climates.

The surveillance programme (SP) calls upon to predict head reactor pressure vessel (RPV) material characteristics conservatively to guarantee RPV structural integrity without any compromise. General vice of existing SPs is an impossibility of SP changing and development during reactor operation (30, 60 and even more years). Up to day, approach based on initial hard nomenclature of surveillance specimens installed in capsules. Therefore, practically it is impossible to change anything in SP during RPV service life. Anachronistic principle of ahead of time, for some decades of years in advance fabrication and installation into reactor vessel the sets of surveillance specimens (SS) without taking into account quantitative and qualitative changes of norms; state of the present-day science, testing methods and technique contradict to request of RPV operational monitoring technologies innovative development during long-term light water reactor (LWR) operation. We propose to improve LWR SPs by means of passage from existing «hard» SPs to «flexible» manageable SPs (MSP) that would give the possibility of SP adaptation to requirements of time and to strengthen technical and scientific potential of investigators and researchers in the future. So, we believe that is no sense to leave present-day level of knowledge and technology in congeal state to next generation of researchers. Thus for new LWRs with the service life of 60 and more years we propose pass on from the SSs of routine nomenclature to MSP i.e., sets of archive materials coupons placed in non-hermetic containers and cooled directly by running water. It gives a perspective in case of need put into practice an innovative MSP taking into account the state-of-the-art safety standards, technical progress, present day level of science and technology.

Self-compacting concrete (SCC) has high flow ability and high resistance to segregation and bleeding. These characteristics facilitate the mixing, casting and finishing of SCC without using compacting or vibrating machines. Adding mineral admixtures, such as fly ash (FA), and superplasticizers improves SCC properties by preventing segregation and bleeding and by increasing rheological parameters. SCC requires high flow ability under the influence of self-weight to completely fill all mold parts for full compaction. This paper discusses the results of an experimental investigation on the properties of SCC and self-compacting fiber reinforced concrete (SCFRC) mixtures with the inclusion of polypropylene fibers (PFs) and containing FA at replacement rates of 0%, 20%, 40%, and 60 % cement mass. The compressive, flexural, and split tensile strengths of the prepared concrete samples were investigated at ages of 7, 14, 28, and 90 days. The workability of fresh concrete mixtures was also studied through segregation, bleeding, slump flow, slump flow T50, L-box V-funnel T5, and V-funnel tests. Results showed that the best properties of fresh SCCs were obtained when FA was added at replacement rates of 20% and 40% cement mass. In addition, the inclusion of PFs at a volumetric ratio of 0.22% decreased segregation and bleeding and improved the flexural and tensile strengths of SCFRCs.

Steel plate shear wall (SPSW) according extra ductility and high strength and lateral stiffness and improved behavior in plastic stage recognized as a good lateral system for building structure, particularly as it interests with earthquake resistant design. Improvise of opening is one advantage of this system. The researchers on perforated steel plate shear wall have shown that the shear strength and stiffness of an un-stiffened steel shear wall decrease due to perforation of the infill plate. So stiffener leads to increasing stability of structural system of buckling and strength, lateral stiffness. To this research still plate shear wall with opening that can be of different material such as rebar, steel plate also effect of increase and decrease of steel plate section area and effect of its dimension studied. Analysis result was observed that applying steel plate with similar area, leads to more ultimate strength. In additionally ultimate strength increase when area increased. With comparing of result of stiffeners dimension due maximum ultimate shear strength. Finally suggest optimum aspect ratio (b/t).

Safety Index has been considered as an important quantitative method used to track safety changes, ranking a problem and also helps in facilitating the decision-making process. The main objective of this research was to develop a new safety index for the workers of medium scale manufacturing industries of Punjab using Delphi method with involvement of means and weights of the factors. To check the validity of the factors content validity index (CVI) was used, by taking expert opinion. The reliability of safety index was also examined by the analysis of data collected from 30 medium scale iron and steel manufacturing industries of Punjab, 10 workers were selected from each industry in order to fill the questionnaire. After calculating the results the standard value of safety index was found to be equal to 21.02 and the analysis of survey data suggested that all the 30 medium scale industries were below the standards of safety index. It means very less safety measures are maintained in the industries of Punjab and the working environment is found to be dangerous and unsafe for the workers of these industries. The main reason behind this scenario is the lack of knowledge among the workers and the greed of owners who don’t want to spend money on maintaining the safety measures. It is recommended to management of industries to improve or maintain their safety factors, so that the workers should feel safe and comfortable at the workplace.

This paper reviews the applications of Industry 4.0 concepts within the aerospace manufacturing processes. A contextual overview of Robotics, Additive Manufacturing, Augmented Reality, Internet of Things, Simulation and Aircraft Industry is provided. Some applications of Robotics integrated with other Industry 4.0 principles are showed to present the trends of Industry 4.0 principles in different areas of aircraft manufacturing. This paper presents some innovations in aerospace industry related to Industry 4.0 and how its benefits and advantages can be reached dayby-day. Finally, it has been concluded that Industry 4.0 brings gains productivity, quality, costs reduction and increase the competitiveness of any business.

Reinforced concrete structures show a very good durability as it is capable of withstanding the different kind of environmental exposure. However, the main limitation of concrete, even of good quality, is that the penetration of chlorides, carbon dioxide (CO2 ), moisture, etc., can cause the corrosion of reinforcement bars (rebars). Corrosion of structure can be reduced by proper monitoring and taking suitable control measures at the proper time interval. Detailed review of corrosion of reinforced steel in concrete and its control has been studied and are presented in this paper.