Effects of non-uniform shrinkage on the long-term behaviour of composite steel-concrete slabs

2015 ◽  
Vol 15 (2) ◽  
pp. 415-432 ◽  
Author(s):  
Safat Al-deen ◽  
Gianluca Ranzi
2021 ◽  
Vol 12 (1) ◽  
pp. 223
Author(s):  
Md Mahfuzur Rahman ◽  
Gianluca Ranzi

Composite steel–concrete slab is a floor typology widely used for building applications. Their design is usually governed by serviceability limit state requirements associated with the time-dependent response of the concrete. In this context, this paper presents a state-of-the-art review of research carried out to date on the long-term behavior of composite steel–concrete slabs. The particularity of this time-dependent response relies on the fact that the concrete cannot dry from the underside of the slab due to the presence of the profiled sheeting while it can dry from its upper surface. In the first part of the paper, a review of the work carried out on the identification of the time-dependent response of the concrete is presented by considering the peculiarities that occur due to the non-symmetric drying condition related to composite slabs. Particular attention is given to shrinkage effects and to the occurrence and influence of the non-uniform shrinkage gradient that develops in this form of construction over time. This is followed by the description and discussion of the experimental work performed on both simply-supported and continuous static configurations of composite slabs. In particular, the work published to date is summarized while highlighting the key parameters of the test samples and of the testing protocols adopted in the experiments. In the last part of the paper, available theoretical and design models proposed for the predictions of the shrinkage-induced behavior of composite slabs are presented and discussed.


2021 ◽  
pp. 41-59
Author(s):  
Gianluca Ranzi ◽  
Raymond Ian Gilbert

<p>This chapter presents a state-of-the-art review of work published to date on the time-dependent response of composite steel-concrete slabs. The key components of this form of construction are introduced in the first part of the chapter, followed by a review of the time-dependent behaviour of the concrete and how it affects the in-service response of composite slabs. Throughout the chapter, particular attention is given to recent experimental and modelling work related to concrete time effects, and how these affect the in-service response of composite slabs, including the development of non-uniform shrinkage gradients that have been recently shown to occur in composite floors due to the inability of the concrete to dry from its underside because of the presence of the profiled steel sheeting.</p>


2020 ◽  
Vol 310 ◽  
pp. 00061
Author(s):  
Sergej Priganc ◽  
Darina Kušnírová

The shrinkage is a significant phenomenon in concrete structures. The article is aimed at monitoring the shrinking of concrete slabs under laboratory conditions. The results of laboratory research aimed at unreinforced slabs strains affected by the non-homogeneity of concrete are mentioned in the article. According to these results another research of shrinkage influence on strains and deflection of concrete slabs reinforced by steel, resp. GFRP reinforcement has been prepared. The results of this research confirm the significant effect of concrete non-homogeneity on the formation of strains and deflections due to shrinkage.


2010 ◽  
Vol 636-637 ◽  
pp. 1059-1064 ◽  
Author(s):  
E.V. Pereira ◽  
R.B. Figueira ◽  
Manuela M. Salta ◽  
I.T.E. Fonseca

In this paper the efficiency of two organic corrosion inhibitors, a migratory and an admixture inhibitor, was evaluated by electrochemical techniques in solutions simulating the interstitial electrolyte of concrete and on concrete slabs exposed to natural environmental conditions over a five-year period. From obtained results, the usefulness of the two products is discussed aiming its application in new structures to prevent chlorides induced corrosion and as a curative method for repairing reinforced concrete structures contaminated with chlorides and affected by reinforcement corrosion.


Author(s):  
Sergey B. Krylov ◽  
Vladimir A. Semenov ◽  
Denis V. Konin ◽  
Alexey S. Krylov ◽  
Lidiya S. Rozhkova

The paper provides a brief overview of domestic and foreign guidelines (manuals) for the design of composite steel and concrete structures: steel-concrete slabs on profiled flooring, combined beams, and columns with rigid reinforcement. The necessity of creation of the actual manual corresponding to the modernlevel of development of construction science, normative documents and design practiceslinked to the new formulary SP 266.1325800.2016 is proved. It will facilitate the design, reduce labor expenditures and improve the reliability of composite steel and concrete structures. The new guidance provides general recommendations for the design of composite steel and concrete structures and the basic regulations for the calculations. The new guidance describes recommendations for modeling of composite steel and concrete structures and elements in the calculated complexes, the recommendations for calculation of combined beams fully concreting rectangular and T-section, partially concreting along with support slab on the lower flange of the beam, columns with rigid reinforcement, shear a connection of composite beams. Recommendations on the registration of creep, shrinkage and crack formation in the appointment of the modulus of elasticity are given. Recommendations on the use of diagrams of the state of concrete, reinforcement, and steel in the calculation of steel-concrete elements on a nonlinear deformation model are given. Recommendations on the use of the range of sheet flooring for steel-reinforced concrete slabs, as well as metal profiles as steel beams and rigid reinforcement in the cross sections of columns and combined beams, are presented. Recommendations on a design of units and details of composite steel and concrete structures are given, refined recommendations on buffer are presented. The examples of connection of steel beams with columns with rigid reinforcement are given. The examples of calculation of composite steel and concrete structures taking subject to the recommendations given in the Manual are presented.


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