Sharif Digital Repository

This study presents the experimental investigation, the effect of cement based chemical materials (Portland cement as a repair material No1. and 2 other cement base chemical materials) to upgrade the structural behavior of reinforced concrete slabs built with low quality (porous) concrete. Because materials used in this study are cement base it is expectable to behavior same as base concrete that its result is better compatibility with base structure against external factors. Other advantages of the use of these materials are consideration of economical and construction aspects. A total of four reinforced concrete column (200x200x800 mm) with low quality (porous) concrete have been built,... 

This study presents the experimental investigation, the effect of cement based chemical materials (Portland cement as a repair material No1. and 2 other cement base chemical materials) to upgrade the structural behavior of reinforced concrete slabs built with low quality (porous) concrete. The main issues focused in this investigation are: (i) the effect of repair on the flexural behavior of RC slabs in terms of ultimate capacity and ultimate mid-span deflection and ductility of specimens, (ii) the influence of repair materials on failure modes and (iii) evaluating the efficiency of different materials on decreasing the porosity of concrete by ultrasonic test. Because materials used in this... 

In this thesis, overall design of a multi-purpose vehicle for transportation, repair and cleaning missions in hydro power station water ways during overhaul is presented. Design process is divided into several parts. The main challenges of the project and customer requirements are discussed first. A brief review of electric vehicles history is presented. The conceptual design including initial dimensional calculations, energy analysis and component selection are described in subsequent sections. Finally the structural and dynamic analysis of chassis and suspension system are carried out. To avoid pollution and life hazards to workers, a battery and electric motor drive system is utilized.... 

Due to well mechanical properties and high resistance to environmental conditions, metal pipes are used to transport oil and gas products, water and sewage, as well as hydraulic systems in aircraft or aerospace systems. Therefore, maintenance of oil and gas transmission lines in energy-related industries and pressurized tanks in the aviation industry has always been a concern of engineers. Due to the problems of old methods for repairing damaged pipelines or aerial structures, it seems necessary to provide new, safe and cheap methods for repairing them. Various engineering standards for pipelines and their repairs have been presented so far which have analytical solutions to determine the... 

The development of the methods to evaluate the seismic resilience of communities, infrastructures, and structures has attracted many researches. To estimate the resilience with accuracy, developing a model that can simulate the events during the recovery time is very important. For the same, modelling the aftershocks with their accumulative effects on the damaged buildings during the recovery time has been the main focus of the current study. The proposed approach to simulate the aftershocks’ effect utilizes the Monte-Carlo sampling, in which each sample includes the two following steps. The first step is the simulation of the cumulative damage caused by the mainshock-aftershocks sequence... 

The repair of pipes that deteriorate over time or due to various factors is a critical issue in engineering. Consequently, effective and novel repair methods, especially using FRP (Fiber-Reinforced Polymer) composites, have gained significant importance. In this research, the repair and connection of pipes using FRP are examined. In the pipe repair section, through hydrostatic testing, various factors such as the damaged area, the number of sharp corner points, the width of the sheets, the number of layers, and the pre- stress condition of the FRP are studied for their impact on the pipe's ultimate pressure tolerance. Also, in the pipe connection section, with hydrostatic tests, the ultimate...