Structural solution of the horizontal joint of floor slabs in girderless frame

Despite the widespread use of monolithic construction, precast concrete remains in demand in the construction of residential and administrative buildings. Regardless of the advantages in technology and the quality of work, it is necessary and appropriate to modernize the existing design solutions, which allows you to simplify and speed up the technological operations during construction. Moreover, in the construction of complex nodes and joints, the qualification of workers is important, so simplifying the work without losing the quality of construction and ensuring strength, stability and durability is an important task. This problem can be solved by using modern embedded parts in the joints that do not require welding and other complex technological operations. In this paper, a constructive solution of the horizontal joint of the floor slabs located in the zone of action of minimal forces is proposed on the example of a girderless frame. The purpose of the study is to determine the stress-strain state of the proposed structural solution of the horizontal joint of floor slabs using loopshaped embedded parts «PFEIFER» and to develop recommendations for determining the shear compliance. Based on the analysis of the results of numerical modeling, the features of the stress-strain state of the joint during shear operation are revealed. The results obtained can be used in the design of buildings with precast-monolithic ringless frames, in the modernization of existing standard solutions of precast-monolithic frames, as well as other load-bearing systems made of precast concrete.

Vocational Colleges and Small, Medium and Micro Enterprises Carry out “Horizontal Joint Innovation, Vertical Integration and Educating People” Cooperation under the Concept of “Innovation, Green and Sharing”

As a part of higher vocational graduates work for small, medium and micro enterprises, vocational colleges should regard serving small, medium and micro enterprises as one of the goal orientation of talent training, and establish a platform of mutual trust and cooperation with them, which can not only meet the employment needs of enterprises, but also enable the high-skilled compound talents trained by the school to achieve employment smoothly, thereby achieving the goal of education and teaching and achieving a win-win situation between the school and the enterprise. This article focuses on analyzing the benefit-driven mechanism that promotes the cooperation between vocational colleges and small, medium and micro enterprises, and proposes a cooperation mode of “horizontal joint innovation and vertical integration and educating people” to promote the benign development of vocational colleges and small, medium and micro enterprises’ production-study-research cooperation, strengthens the connotation construction of vocational colleges, provides a reference basis for small and medium enterprises to enhance their overall competitiveness, and achieves a good situation of mutual promotion and common development of education and industry.

Modernization of the design solution of the horizontal joint of the floor slabs in the beam-free frames using seamless loop-shaped embedded parts

There is proposed an updated design solution of horizontal joint of the floor slabs for CUB and UIKSS beam-free frames using PFEIFER loop-shaped embedded fixings. On the basis of numerical modeling, the features of its stress strain behavior during shear operation are revealed. The horizontal joint of prefabricated floor slabs with seamless looped-shaped embedded parts has been modernized and an analytical expression to determine its compliance based on the analysis of the results of numerical simulation of the shear has been obtained. There is presented a comparative analysis of the calculation results and experimental data, proving the adequacy and applicability of the proposed calculation expression and the applicability of the design solution. The new design solution of the horizontal joint of floor slabs simplifies the technology of slab installation, and its shear suppleness can be assessed as a positive factor for the construction industry.

The Experimental Investigation of the Internal Support Effects on Exhaust Casing Pressure Recovery

As is well known, the performance of the last stage of the low pressure part of a steam turbine is strongly influenced by the effectivity of the downstream exhaust casing. The efficiency of the exhaust hood depends on many structural factors such as the design of the diffuser parts, dimensions of the outer casing or arrangement of internal supports. The aim of this paper is the experimental study of the influence of the internal supports of the axial-radial exhaust hood on its pressure recovery factor. For one geometry of its diffuser parts a few different variations of internal supports such as T-rib, tube grid or BV were tested. The effect of reducing the width of exhaust hood in the horizontal joint and the changing of axial length of the diffuser were observed. The width of exhaust hood in horizontal joint and the axial length of the diffuser define the area in the horizontal joint of the exhaust hood. How the diffuser behaves when reducing this area is very important in retrofitting of old machines, where there are so many geometric constrains. The effect of wall jet blowing into the diffuser wall was also evaluated. In this paper we concentrate to examine the sensitivity of these certain geometrical parameters of exhaust hood on the pressure recovery of the whole exhaust system of the low pressure part of the steam turbine. The main purpose of our analysis and experimental measuring was optimising the axial-radial exhaust hood of the steam turbine. For this reason, wind tunnel facilities with relevant measuring and traversing systems were designed and built. The measurements have been performed on 1/5th scale test rig which enabled rapid and efficient evaluation of multiple geometrical variants. The observed exhaust hood was designed for an extra long 54inch last stage blade. For measurements of flow parameters was used multi-hole pneumatic pressure probes and wall pressure taps in conjunction with CFD tools to explore physics based alterations to the exhaust configuration.

THERMAL BEHAVIOR OF SINGLE-LEAF WALLS FOR BUILDINGS, MADE WITH LIGHTWEIGHT CERAMIC CLAY BRICKS

<p>In recent years, several studies about factors influencing the heat transfer in single-leaf walls composed by lightweight ceramic bricks of large format have been made, in order to reduce energy losses. Separate works have highlighted the relevance of some parts composing the wall such as the different types of internal voids in the brick, different types of tongue and groove system and different types of horizontal joint. This paper seeks to integrate these studies in order to give an overview of factors that influence the heat transfer and study the importance of each one of them, from an energy point of view. For this purpose, the influence of every factor in the equivalent thermal transmittance of the external walls of building is compared.</p><p>It is remarkable that a single-leaf wall built with a geometrically optimized brick and thin horizontal joint gives masonry wall many significant advantages, because the amount of heat flux dissipated through the horizontal mortar joint is greatly reduced. Better insulated walls mean that there is less need to use home heating and cooling systems. This means less energy consumption and a proportional decrease in GHG emissions, in line with the objectives for 2020 set in the EEP.</p>