Time dependant behaviour of SFRC elements under sustained loads

Author(s): D. Nakov, G. Markovski
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: 796 - 808
Total Pages: 12
Language: English

Abstract: 
The benefits of steel fibre reinforced concrete in combination with ordinary reinforcement are well proven in many structures. Decreasing deformations and increasing the number of cracks by decreasing their width are the main reasons for its usage. Up until now, many experiments have been performed on SFRC elements subjected to short term load. Concrete is a material whose properties are changing due to aging and the behaviour of concrete elements depends also on the time duration of the load. There are some long term experiments performed on SFRC elements in the past, but with different conclusions. Somewhere it is stated that fibres do not have a big influence on creep and shrinkage strains and somewhere that they do have one. This is probably the result of different test setups, types of fibres, temperature and humidity. We have chosen hooked-end steel fibres with l=50mm and d=1mm. Previous theoretical and experimental investigations using reinforced, pre-stressed and high strength concrete elements, performed at Ss. Cyril and Methodius University, [8] and [9], have proven that creep and shrinkage have significant influence on the stress state of the elements, increasing the deformations and crack widths. In this context, it is expected that the addition of steel fibres in reinforced concrete will improve these negative characteristics. The experimental program consists of 24 full scale beams made from reinforced and SFRC (C30/37) with 30kg/m3 and 60 kg/m3 fibres and additional reinforcement. On part of the beams, short term ultimate load testing will be performed on 40 and 400 days. Other beams will be pre-cracked and long term load will be applied on them, while on other beams, beside the permanent, specific variable repeated load will be applied with 8h loading and 16h unloading each day within one year, trying to simulate a realistic load history.

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