توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱APPLICATION OF EXPANSIVE AGENT (EA) TO PRODUCE POST TENSIONING FORCE IN FRP JACKETS FOR LATERAL RETROFITTING OF RC COLUMNS
نویسنده(ها): ، ،
اطلاعات انتشار: سومین کنفرانس بین المللی بتن و توسعه، سال
تعداد صفحات: ۷
Repair and strengthening of RC structures using FRP materials is one of the new and effective techniques ever used. With this respect, strengthening of structural elements by external lateral confinement can lead to increased strength and ductility. In this way, using an efficient and optimized method for lateral confinement is of great importance. A novel, economic and simple technique for the repair and strengthening of RC members by means of expansive agent(EA) to produce post tensioning force, has been proven to perform well following experimental work undertaken at the University of Sheffield. The aim of the technique is to ensure the enhancement of
the member strength and ductility by localized strengthening. The above technique is equivalent to increasing the effectiveness of the composite confinement and it becomes possible to strengthen large columns with smaller amounts of composites, which are utilized earlier at much higher strengths. In addition, the level of axial strain achieved at failure is improved significantly. The paper will present details of experimental work with different types of confining material (glass and carbon), amounts of reinforcement and levels of initial prestressing.<\div>

۲INFLUENCE OF WATERPROOFING ADMIXTURE IN WATER PENETRATION OF CONCRETE
نویسنده(ها): ، ، ،
اطلاعات انتشار: سومین کنفرانس بین المللی بتن و توسعه، سال
تعداد صفحات: ۹
Nowadays, concrete plays an outstanding role in construction industry and variety of engineering infrastructures such as bridges, dams, jetties, piers and channels which are made of concrete. Since from one hand, these huge and critical concrete structures in which some cases are of lifelines of a country are of great importance and on the other hand, the necessity of conservation and durability of these
structures is inevitable, the importance of concrete durability will become vividly apparent. One of the factors that can deteriorate the reinforced concrete condition by corrosion and cause cracking in severe cold weather, has turned out to be water penetration into concrete. With this respect, one of the practical and efficient ways ever used to countermeasure this situation is to use water proof additives in concrete mix in order to reduce water and waste water absorption and penetration into concrete. In this investigation, PN gel, PN liquid and PN liquid along with micro silica powder as waterproofing additives, were used in separate mix designs to make specimens and then these specimens and the witness were tested by two methods in order to determine water absorption and penetration depth in concrete. in one of these two methods, water absorption percentage was just determined and in the other one which was more accurate and was implemented by triaxial apparatus, both water absorption and penetration depth in the specimens were investigated. Finally, the tables and diagrams for gained results concerning specimens containing PN additives and witness were prepared and compared. The
results showed about more than 50% improvement in water penetration reduction.<\div>
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