Experimental and numerical analysis of SFRC ground slabs under point loading on elastic sub-base

Author(s): I. Gokalpl, O.T. Turan, M. Aydogan, M.A. Tasdemir
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: 1409 - 1418
Total Pages: 9
Language: English

Abstract: 
Steel fibre reinforced concrete (SFRC) has a wide range of applications such as: pavements and overlays, industrial floors, precast elements, hydraulic and marine structures, repairing and retrofitting of reinforced concrete structures, tunnel linings and slope stabilization works. Especially, major applications of SFRCs are pavements and other types of slabs and decks. Small industrial floors are mainly subjected to impact and other mechanical loads, however, large industrial floors and large airport runways have to resist shrinkage and thermal cracking, as well as the mechanical loads.

In comparison with non-reinforced floors, the addition of steel fibres results in a significant increase in impact resistance and toughness. In the assessment of the behaviour of slabs on an elastic subbase, toughness plays a decisive role in the load bearing and deformation behaviour. The aim of this study is to investigate the influence of the fibre content and elastic sub-base modulus on SFRC ground slabs under punching load on an elastic sub-base.

The full scale investigations were carried out on eight slabs with the dimensions of 3.0 m. x 3.0 m. x 0.15 m. The steel fibres are provided with hooked ends and have a minimum tensile strength of 1050 N/mm2. The fibres used in tests were 60 mm in length and 0.75 mm in diameter. In the production of SFRC ground slabs, three steel fiber volume fractions (0.19%, 0.26%, and 0.32%) and four types of elastic sub-base with different elasticity moduli were used. The properties of concrete, type and aspect ratio of steel fibers, and properties of sub ground were kept constant. To obtain different elastic sub-base moduli, different types of extruded polystyrene foam plates, and a rubber sheet in different thicknesses were used.

The slabs were tested under an increasing punching load via a 0.15 m. x 0.15 m steel plate with an hydraulic jack. This single load leads to a comparatively unfavorable slab loading, and simulates for example a vehicle load or the load exerted by a rack storage system. The load was applied in steps of 10 kN until the failure of the slab. The vertical displacements were recorded for each loading step at 16 points on the surface of the slabs by using transducers with a 1/1000 mm precision. Measurements related with crack openings were also performed at different loading steps during the test process.

The tests were modeled with a special software to perform a nonlinear finite element analysis and the results of the numerical analyses were compared with the experimental results.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00