Residual behavior of reinforced steel fiber‐reinforced concrete beams damaged by impact

Abstract

The awareness of damage caused by impacts in civil structures has increased during the last decades. Existing research has shown that impact strength of concrete structures can be improved with the addition of steel fibers, but little attention has been paid at the assessment of the structural condition after the impact. In fact, the residual capacity of reinforced steel fiber‐reinforced concrete (SFRC) can be considered as one of the main advantages of the employ of SFRC in structures expected to suffer impact damage. The understanding of the residual capacity of impact‐damaged structures, in terms of strength and energy absorption, might be decisive to safely perform evacuation and recovery operations, as well as evaluate rehabilitation tasks. This paper presents a research on the residual capacity of preimpacted reinforced SFRC beams. Seven mixtures of SFRC are evaluated, including three types of steel fibers and two values of fiber amount (as well as companion unreinforced plain concrete mixture). The research includes an experimental campaign as well as a model to understand the contribution of the SFRC to the strength and ductility of undamaged and damaged specimens. Among the conclusions, it has been found out that the failure mode (i.e., shear‐ or flexure‐governed) of damaged specimens depends on the crack pattern caused by the impact, and it can be different from the failure mode of undamaged specimens.

Experimental and numerical study on concrete beams reinforced with Basalt FRP bars under static and impact loads

“…The residual load-carrying capacity of concrete beams after the impact tests could be used to evaluate the damage level of concrete beams based on some indices [36,57] such as the ratio of the post-impact…”

Lif Katkılı Beton ile Üretilen Enine Donatılı Betonarme Kirişlerin Eğilme Etkisi Altındaki Doğrusal Olmayan Analizi

“…Serdar vd (2020) tarafından, literatürden seçilen deneysel çalışma [7] sonuçları kullanılarak sonlu eleman modelinin uyumlu sonuçlar verdiği belirlenmiştir. Deneysel çalışma [7] da numune olarak kullanılan kiriş 125x250 mm dikdörtgen kesite sahiptir. Çekme ve basınç bölgelerinde 2'şer adet 16 mm çapında nervürlü donatı mevcuttur.…”

“…Serdar ve diğ, literatürden seçtikleri deneysel çalışma [7] ile doğrulama yapmışlardır. Deneysel çalışma ve numerik analizlere ait yük-deplasman eğrileri şekil 2a ve 2b'de görülmektedir.…”

Eğilme Etkisi Altındaki Lifli Betonarme Kirişlerin Doğrusal Olmayan Analizi

“…Literatürden seçilen deneysel çalışma [7] sonuçları kullanılarak sonlu eleman modelinin doğrulanması yapılmıştır. Ulzurrun ve Zanuy [7] tarafından gerçekleştirilen deneysel çalışmada kiriş numunesi 2 m açıklığında 125x250 mm dikdörtgen kesite sahiptir. Basınç ve çekme bölgesinde 16 mm çapında 2 adet nervürlü donatı yerleştirilmiştir.…”