Two novel demountable shear connectors for precast steel-concrete composite bridges are presented. The connectors use high-strength steel bolts, which are fastened to the steel beam with the aid of a special locking configuration that prevents slip of bolts within their holes. Moreover, the connectors promote accelerated construction and overcome typical construction tolerances issues of precast structures. Most importantly, the connectors allow bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (1) precast deck panels can be rapidly uplifted and replaced; (2) connectors can be rapidly removed and replaced; and (3) steel beams can be replaced, while precast decks and shear connectors can be reused. A series of push-out tests and a beam test were conducted to assess the behavior of the connectors and quantify the effect of important parameters. The experimental results showed that shear resistance and slip capacity can reach 2.5 and 2.7 times respectively of those of welded shear studs along with superior stiffness and strength against slab uplift. Additionally, shear stiffness of M16 mm LNSC was equal to that of M19 mm welded studs. Identical tests reveal negligible scatter in the shear load – slip displacement behavior. Design equations are proposed to predict the shear resistance with minimum deviations.
This research is divided into a process of classifying and filtering most of the studies that dealt with sustainable professional development and dividing them into several sections to determine the categories for which sustainable professional development is measured, which categories did not address it, the extent to which the samples deal with and their number of the target variable, as well as the variables that suit sustainable professional development and the variables that did not Study it yet. And also the quality of studies in terms of the methodology used so that there is a reference for every researcher who intends to study sustainable professional development with studies, their characteristics, categories, tools and methodology
... Show MoreTo move forward on the path of goodness and peace, we must realize that, in the midst of the great diversity of cultures and forms of human life in the world, that we form one human nation, which God Almighty created to worship Him on His earth and under His heavens and to enjoy His bounties and natural resources that God Almighty has bestowed upon that nation. On one land, and it is governed by one common destiny. Every country has been endowed with a natural resource by God Almighty that distinguishes it from the other country to live in prosperity if these wealth are distributed equally among the members of the same society and societal justice is achieved. We must join together to work for the establishment of a sustainable global commu
... Show MoreThe unbalanced distribution of investments in the economic fields of the 1950s had a negative impact on the overall economic life of the country in that period and subsequent periods. Since the 1960s, the planning agencies have tried to reduce the negative impact of imbalance in regional development and the emergence of disparities in development between the regions of the country and to identify disparities in levels of spatial development. At the planning level, there have been many studies and mathematical and statistical models to analyze variance and clarify its dimensions and to measure the degree of developmental disparity between Regions and means of narrowing this problem and the development of policies and strategies for develo
... Show MoreThe research is a vision of the future of industry in Iraq, so it is may be outside the ceiling of the capabilities of the Iraqi economy, and therefore it is exaggerated. Therefore, future plans must be applicable through the availability of capabilities. Everyone knows that the financial and administrative corruption and mismanagement of resources are the main cause of the inefficiency of the industrial sector, and the failure to exercise its real role in achieving economic development.; as well as the political situation and the dominance of parties and their insistence on addressing positions that have a strong relationship in managing the economic sector that has a significant impact on drawing the economic map in its current
... Show Morethe regional and spatial dimension of development planning must be taken as a point of departure to the mutual of the spatial structure of the economy , development strategy and policies applied 'therein such as the location principles and regional development coordination of the territorial problems with the national development planning and timing of regional vis-a-vis national development plan_. Certain balance and integration is of sound necessity' between national _regional and local development objectives through which the national development strategy should have to represent the guidelines of the local development aspirations and goals. The economic development exerts an impact on the spatial evolution, being itself subje
... Show MorePlay constitutes a significant means for children to figure out the world around. Play helps children to have a healthy brain that increase their creativity via developing emotional, cognitive, physical strength. Thus, the current research aims to identify the role of play in psychological development of children. The findings of study revealed that play develops children’s cognitive, emotional abilities and enhances their self-confidence. Play forms a major approach for learning that promotes children to get rid of stress. Additionally, it supports language development of children
Urbanization can not be seen as a modern phenomenon. It has led people to live and live in cities for thousands of years. It should be noted here that the oldest villages and large cities have emerged after the crystallization of civilization, that the emergence of cities was one of the phenomena of civilization. There is no doubt that the cities after the emergence has contributed to the development of civilization effective contribution. There has been a civilizational progress when the man practiced agriculture and used metal tools and invented the wheels and went to write in the New Stone Age. In this period, many changes in the field have taken place in economic, cultural and social life. In the economic and cultural aspect, this tr
... Show MoreThis paper has investigated experimentally the dynamic buckling behavior of AISI 303 stainless steel Aluminized and as received long columns. These columns, hot-dip aluminized and as received, are tested under dynamic buckling, 22 specimens, without aluminizing (type 1), and 50 specimens, with hot-dip aluminizing at different aluminizing conditions of dipping temperature and dipping time (type 2), are tested under dynamic compression loading and under dynamic combined loading (compression and bending) by using a rotating buckling test machine. The experimental results are compared with Perry Robertson interaction formula that used for long columns. Greenhill formula is used to get a mathematical model that descripts the buckling behavior
... Show MoreThe present investigation aims to study the effect of heat treatment by quenching in different quenching media (salt water, water and oil) following by tempering on wear resistance of EN25 steel. EN25 steel is an alloy of medium carbon low alloy steel which is used for many applications requiring high tensile strength and wear resistance such as connecting rods, adapters and in power sectors extensively. The specimens are machined to 20 mm in length and 10 mm in diameter. This study is done by two stages: The first stage is done by austenitizing EN25 steel to 850 for 1 hr by quenching the specimens in three different quenching media and then tempered at 300 in air. While the second stage is performed by wear
... Show MoreCooling towers is one of the most important unit in industry, they are used to dispose heat from cooling media used in the integrated units. The choice of the cooling media plays recently an important rule due to fresh-water scarcity. The use of saline as a cooling media become of growing interest, but the corrosion problem has to be taken in consideration. In this study the simultaneous effect of cooling tower operation parameters on the corrosion rate of mild-steel is considered. The role of NaCl content is found to be pronounced more than the working solution temperature and flowrate. The corrosion of mild-steel in these studied factors had shown an interesting result especially with the NaCl% content. Firstly, there was an increase in t
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