scholarly journals Effects of transient creep strain on post-tensioned concrete slabs in fire

2017 ◽  
Vol 69 (7) ◽  
pp. 337-346 ◽  
Author(s):  
Ya Wei ◽  
Francis T. K. Au ◽  
Jing Li ◽  
Neil C. M. Tsang
Keyword(s):  
Creep Strain ◽  
Transient Creep ◽  
Concrete Slabs ◽  
In Fire ◽  
Transient Creep Strain ◽  
Post Tensioned

scholarly journals Unbonded Post Tensioned Concrete Slabs in Fire - Part II - Modelling Tendon Response and the Consequences of Localized Heating

2011 ◽  
Vol 2 (3) ◽  
pp. 155-172 ◽  
Author(s):  
John Gales ◽  
Luke Bisby ◽  
Martin Gillie
Keyword(s):  
Concrete Slabs ◽  
Localized Heating ◽  
In Fire ◽  
Post Tensioned

Tensile Properties and Creep Behavior of Compositional Modified Orthorhombic Ti2AlNb Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 1549-1552 ◽  
Author(s):  
Yong Mao ◽  
Masuo Hagiwara
Keyword(s):  
Tensile Properties ◽  
Creep Strain ◽  
Room Temperature ◽  
Transient Creep ◽  
Steady State Creep ◽  
Plasma Arc ◽  
Steady State Creep Rate ◽  
Arc Melting ◽  
Cr Addition ◽  
Transient Creep Strain

Several beta stabilizing elements such as Mo, Cr, W, V and Fe have been added to Ti- 22Al-27Nb alloy for substituting a portion of Nb in order to further improve the tensile properties and creep resistances of orthorhombic Ti2AlNb-based alloys. Six compositional modified alloys Ti- 22Al-19.2Nb-2Cr, Ti-22Al-12.5Nb-2W-2Cr, Ti-22Al-10.8Nb-2Mo-2Cr, Ti-22Al-16Nb-2Cr-2V, Ti-22Al-11Nb-2Mo-1Fe, Ti-22Al-16.3Nb-2V-1Fe were prepared by plasma arc melting. The phase constitutions of these alloys were found to be B2+O or B2+O+α2 phases. The tensile properties were investigated at room temperature, and the creep behaviors were investigated under 650oC/310MPa and 650 to 750oC/200MPa. The results showed that Mo+Fe and W+Cr addition improved effectively the 0.2% yield strength and creep resistance. Ti-22Al-11Nb-2Mo-1Fe alloy exhibited the lower transient creep strain and steady-state creep rate, and longer 1% creep-strain lifetime than Ti-22Al-27Nb alloy at 650 to 700oC creep. The dislocation-controlled creep deformation mechanism was suggested to the creep behaviors of the Mo+Fe-modified alloy.

Modelling of bonded post-tensioned concrete slabs in fire

2008 ◽  
Vol 161 (6) ◽  
pp. 311-323 ◽  
Author(s):  
E. A. M. Ellobody ◽  
C. G. Bailey
Keyword(s):  
Concrete Slabs ◽  
In Fire ◽  
Post Tensioned

An Analytical Theory of the Creep Deformation of Materials

1953 ◽  
Vol 20 (2) ◽  
pp. 245-252
Author(s):  
Yoh-Han Pao ◽  
Joseph Marin
Keyword(s):  
Creep Strain ◽  
Creep Deformation ◽  
Elastic Strain ◽  
Transient Creep ◽  
Analytical Theory ◽  
Simultaneous Action ◽  
Creep Recovery ◽  
The Past ◽  
Short Time ◽  
Transient Creep Strain

Abstract This paper reports on the formulation of an analytical theory of creep. This theory is proposed for an idealized material and may be applied to those materials whose behavior conforms to that of this ideal material. The theory takes into account the initial elastic strain, the transient creep strain, and the minimum rate creep strain. Unlike previous theories, this theory is capable of representing the simultaneous action of creep and creep recovery and may be used for conditions of varying as well as constant stresses. In this respect the theory is more general than those presented in the past. The new theory is of particular importance in the design of many new military and domestic applications where high temperatures over short periods of time make the initial short-time creep strains of importance.

Interaction diagrams and failure criteria for RC columns subjected to high temperature

2020 ◽  
Vol 11 (3) ◽  
pp. 347-378
Author(s):  
Khaled Ahmed Mahmoud
Keyword(s):  
Creep Strain ◽  
Elevated Temperatures ◽  
Failure Criteria ◽  
Transient Creep ◽  
Limit Strain ◽  
Experimental Results ◽  
Content Type ◽  
Proposed Model ◽  
Ultimate Limit ◽  
Transient Creep Strain

Purpose Previous works in constructing interaction diagrams have only focused on incorporating transient creep strain implicitly in the ultimate limit strain. The present paper aims to use different approaches to define concrete ultimate limit strain (failure strain) envelops at high temperatures for preloaded and unloaded, confined and unconfined, columns during heating are proposed. These approaches are chosen to understand the effect of using different techniques to determine transient creep strain on the resulted Nu–Mu diagrams. Design/methodology/approach Transient creep strain is included within the concrete ultimate limit strain relationships, implicitly and explicitly, by four different ways, and accordingly, four different failure criteria are suggested. To define the concrete ultimate limit strain, studies are conducted to evaluate the compression strain corresponding to the maximal flexural capacity at elevated temperatures. In the analysis, the thermal and structural analyses are decoupled and, based on the resulted ultimate limit strain, the Nu – Mu diagrams are constructed at different fire exposures. Findings The validity of the proposed model is established by comparing its predictions with experimental results found in the literature. Finally, comparative calculations regarding interaction diagrams obtained by the proposed model and by other methods found in the literature are performed. It was found that the proposed model predictions agree well with experimental results. It was also found that the suggested approaches, which include simplifications, reasonably predicted the exact column capacity. Originality/value The model.

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