Vol.9, No 2, 2011 pp. 205 - 215
UDC 624.072.2:624.012.45:677.52=111
DOI: 10.2298/FUACE1102205A


EXPERIMENTAL ANALYSIS OF R.C. BEAM STRENGTHENED WITH DISCRETE GLASS FIBER
Shoeib Soliman Ata Elkareim*, Osman Moustaf
Civil Department Engineering, Faculty of Engineering, Helwan University, Egypt
E-mail: *ataelkareim_2008@yahoo.com
The usage of discrete glass fiber with concrete provides enhancement the ductility and deformability. This study aims at understanding and evaluating shear behavior of discrete glass fiber concrete beams. This paper presents an experimental investigation carried out on reinforced concrete beams with discrete glass fiber mixed randomly with concrete, with 150150mm cross section. The studied parameters included stirrups spacing (50, 75, and 100 mm) and weight percent of discrete glass fiber (0.0%, 0.75%, and 1.5%). Experimental results indicated that the shear strength of beams was significantly enhanced. Although, the number of cracks increased as a result of using discrete fiber, they became finer. Moreover, the crack propagation and its modes may be changed by using discrete fiber. The discrete glass fiber increases ductility and prevents sudden failure due to shear.
Key words: Discrete glass fiber, Shear strength, Shear cracks.

EKSPERIMENTALNA ANALIZA AB GREDA OJAČANIH DISKRETNIM STAKLENIM VLAKNIMA
Korišćenje diskretnih staklenih vlakana u betonu obezbeđuje poboljšanje duktilnosti i deformabilnosti. Ova studija ima za cilj razumevanje i evaluaciju ponašanja betonskih grednih nosača sa staklenim vlaknima kod smicana. Rad daje eksperimentalno ispitivanje izvršeno na armirano betonskim gredama sa diskretnim staklenim vlaknima nasumično pomešanim sa betonom sa dimenzijama preseka 150x150mm. U studiji su uzengije bile razmaknute (50, 75 i 100 mm) a udeo težine staklenih vlakana je bio (0.0%, 0.75%, i 1.5%). Eksperimentalni rezultati su pokazali da je otpor na smicanje greda bio značajno povećan. Iako se broj prslina uvećao usled korišćenja diskretnih vlakana, one su postale manje. Šta više, širenje prslina i modusi širenja se mogu menjati korišćenjem diskretnih vlakana. Diskretna staklena vlakna povećavaju duktilnost i sprečavaju iznenadni lom usled smicanja.
Ključne reči: Diskretna staklena vlakna, otpor na smicanje, smičuće prsline