钢结构与建筑学报

Fire-resistant and high temperature behavior of high strength steels (HSS) for structural engineering applications has become an important research topic in recent years. In this paper, a succinct review of HSS behavior under and after high temperature exposure is provided. The review addresses the following aspects of HSS: (1) their mechanical properties under and after fire exposure, (2) residual stress in welded HSS sections, and (3) high temperature performance of HSS columns. Recent studies have demonstrated that different grades of HSS can exhibit noticeable differences in their mechanical properties under and after fire exposure, and different cooling methods could have an effect on the post-fire mechanical properties of HSS. Because current design standards for steel structures under elevated temperature were developed based on mild steel, care must be exercised when applying these standards to HSS as they are not necessarily applicable.

In traditional power engineering hydrogen may be one of the first primary sources of equipment damage. This problem has high actuality for both nuclear and thermonuclear power engineering. Study of radiation-hydrogen embrittlement of the steel raises the question concerning the unknown source of hydrogen in reactors. Later unexpectedly high hydrogen concentrations were detected in irradiated graphite. It is necessary to look for this source of hydrogen especially because hydrogen flakes were detected in reactor vessels of Belgian NPPs. As a possible initial hypothesis about the enigmatical source of hydrogen one can propose protons generation during beta-decay of free neutrons поскольку inasmuch as protons detected by researches at nuclear reactors as witness of beta-decay of free neutrons.

Modular construction methods have been adapted globally for the past few decades and are becoming more common due to their ease of use and flexibility. Structural connections between modules are required for integrity and robustness but details vary depending on the form of the module and the particular application. The behaviour of connections in analysis and design of modular buildings should particularly be taken into account in detail because of their effects on the distribution of internal forces and on structural deformations. The purpose of this paper is to present and analyse the behaviours of an innovative steel bracket connection. Experiments, including shear loading and simply supported tests, were carried out to establish directly the ultimate resistance as well as failure modes of the connections. The finite element software, Strand7, was subsequently utilised to produce models for comparison with test results. A parametric study has been carried out to investigate the effects of varying bolthole dimension and bolthole spacing on the structural behaviours of the steel bracket connection using linear analysis. The model presented in this paper was formed as a baseline for future in-depth investigations to ensure design optimisation of the steel bracket connection.

With the movement of cities toward a more industrial urban structure, they need of green environment is increasing. One of the solutions is creating the green roofs which the interest on them is increasing. However, having a green roof requires some technical guidelines to provide the desired environment. The technical guidelines for the instruction of green roof aim to provide an adapted, environmentally friendly and suitable material for offering the optimal operation. This focus of this document is mainly on the technical aspects of the material in need for insulation, roofing membranes and protection material, moisture-retention material and water proofing.

This paper examines the twisting anxieties of steel web decreased I segment cantilevers. Cantilevers with different level of decrease web broke down. The anxiety design along an I segment is recognized and the area and extent of the most extreme bending anxiety are talked about. The basic activity of a customary web decrease I segment under immediate or offbeat stacking is prevalently twisting, with different impacts, for example, distorting, pivot and parallel torsional clasping. The web decreased steel segment cantilever shaft is a broadly utilized auxiliary component as a part of numerous fields of use in light of its various great properties. FEA study on the conduct of steel I-segment (200 mm × 100 mm and 5 m length with a vertical heap of 500 kg) with straight web under stacking is displayed in this course. The examination is made with I segment having same dimensioned level web. The study incorporates bending execution, sidelong torsional clasping. It is presumed that steel bar with decreased web segment has higher imperviousness to twisting, sidelong torsional clasping contrasted with that of an area with level web segment cantilever bar. The point of turn is likewise diminished with increment in decreased proportion. 3:2 decrease proportions are reasonable as the proportionate anxiety is less for this proportion.

Persian gardens are well known for the integration of indoors and outdoors. Shazdeh Garden reflect the profound metaphysical importance of natural beauty in Persian culture. There exists the special relation between sensible heritage and insensible of the humane spirit of the garden of Shazdeh. The Garden was not only a sensible invention but also an important carrier of the Iranian traditional culture. The Garden of Shazdeh showing the people to pursue the profound spiritual comfort of the living environment also were interrelated to the local custom. The Insensible heritage of humane spirit is a good example that the people and nature are in perfect harmony. Also it is impacting on the sensible and spiritual requirements of today

Construction practices involving the rehabilitating, retrofitting, and reinforcing of concrete structures using fiber reinforced polymer (FRP) fabrics have been well documented. Experimental efforts to characterize the effectiveness of this technology, however, have included many large scale FRP-concrete tests for strength/stiffness evaluations which do not detect delamination effects; small-scale tests, on the other hand, only provide average interface strength properties that neither describe failure mechanisms nor provide fracture toughness data. In this paper, the experimental fracture mechanics specimen known as the single contoured-cantilever beam (SCCB) was used to obtain important quantitative results of FRP-concrete interfaces as subject to a host of conditions: dry, freezingthawing, wetting-drying, fatigue, and surface roughness effects on the integrity of the interface bond. The findings of this research effort demonstrate both the importance of surface preparation towards achieving an optimal bond as well as offering a means of gaging rates of degradation of the interface under a variety of commonly encountered construction environments.

In the present study the effect of sodium citrate, calcium nitrate, and hexamine on corrosion of steel was analyzed. The effect of inhibitor on normal consistency of cement, initial and final setting time of cement, compressive strength of cement, soundness of cement and compressive strength of concrete were also analyzed. The results of the study also concluded that hexamine and calcium nitrite are more efficient inhibitor. It showed 45% and 25% inhibitor efficiency at the denseness of 0.5% hexamine and 0.5% calcium nitrite by weight of cement respectively. Further, sodium citrate also prevents the hydration of cement, but it is not suitable as an inhibitor. The addition of Inhibitor acts as retarder for the initial and final setting period of the cement and retard the compressive strength at initial days. After 180 days strength is improved significantly.