Time-Dependent Behavior of High Performance Fiber-Reinforced Concrete

2013 ◽  
Vol 705 ◽  
pp. 75-80 ◽  
Author(s):  
Andina Sprince ◽  
Aleksandrs Korjakins ◽  
Leonids Pakrastinsh

This research deals with experimentally studied time-dependent deformations of polyvinyl alcohol (PVA) fiber reinforced high performance concrete (HPFRC). The creep in compression and crack propagation of the new concrete compositions were determined. Several kind of concrete mixes adding microsilica and nanosilica have been made. For each composition cylinders with dimensions 190x47mm and Compact Tension (CT) specimens with dimensions 150x150x12mm were prepared. Concrete specimens were tested in a controlled constant temperature and with a constant level of moisture. Creep specimens were put into a creep lever test stand and subjected to a uniform, constant compressive load but CT specimens were subjected to a tension load. Deformations and crack mouth opening displacements were measured with extensometers. The compression strength and modulus of elasticity also were determined. The results have shown that nanosilica dont have significant influence on the high performance fiber reinforced concrete time-dependent behavior.

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 63
Author(s):  
Anna L. Mina ◽  
Michael F. Petrou ◽  
Konstantinos G. Trezos

The scope of this paper is to investigate the performance of ultra-high performance fiber reinforced concrete (UHPFRC) concrete slabs, under projectile impact. Mixture performance under impact loading was examined using bullets with 7.62 mm diameter and initial velocity 800 m/s. The UHPFRC, used in this study, consists of a combination of steel fibers of two lengths: 6 mm and 13 mm with the same diameter of 0.16 mm. Six composition mixtures were tested, four UHPFRC, one ultra-high performance concrete (UHPC), without steel fibers, and high strength concrete (HSC). Slabs with thicknesses of 15, 30, 50, and 70 mm were produced and subjected to real shotgun fire in the field. Penetration depth, material volume loss, and crater diameter were measured and analyzed. The test results show that the mixture with a combination of 3% 6 mm and 3% of 13 mm length of steel fibers exhibited the best resistance to projectile impact and only the slabs with 15 mm thickness had perforation. Empirical models that predict the depth of penetration were compared with the experimental results. This material can be used as an overlay to buildings or to construct small precast structures.


2017 ◽  
Vol 10 (1) ◽  
pp. 1-14 ◽  
Author(s):  
P. V. C. N. GAMA ◽  
T. N. BITTENCOURT

Abstract The Ultra-High Performance Fiber-Reinforced Concrete is a material with remarkable mechanical properties and durability when compared to conventional and high performance concrete, which allows its use even without the reinforcement. This paper proposes the design of prestressed towers for a 5 MW turbine, through regulatory provisions and the limit states method, with UHPFRC and the concrete class C50, comparing the differences obtained in the design by parametric analysis, giving the advantages and disadvantages of using this new type of concrete. Important considerations, simplifications and notes are made to the calculation process, as well as in obtaining the prestressing and passive longitudinal and passive transverse reinforcement, highlighting the shear strength of annular sections comparing a model proposed here with recent experimental results present in the literature, which was obtained good agreement. In the end, it is estimated a first value within the constraints here made to ensure the economic viability of the use of UHPFRC in a 100 m prestressed wind tower with a 5 MW turbine.


Author(s):  
Igor Chilin ◽  

Приведены результаты исследований и выполнена оценка влияния технологических факторов на реологические свойства самоуплотняющихся сталефибробетонных смесей, определены кратковременные и длительные физико-механические и деформативные характеристики сверхвысокопрочного сталефибробетона, включая определение его фактической морозостойкости.


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