Kilitli EPS Blok-Yerinde Dökme Beton ve Kilitli EPS Blok-Prekast Beton Arayüz Kayma Mukavemetinin Laboratuvar Deneyleri ile İncelenmesi
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2017
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Geofoam bloklardan inşa edilmiş otoyol dolgularının yanal yükler altındaki tasarımlarında geofoam blokların kendi aralarındaki ara yüzey dayanımları (geofoam blok-geofoam blok) bir tasarım parametresi olarak karşımıza çıkar. Buna ek olarak, geofoam blok otoyol dolgu sisteminin son sırasındaki geofoam bloklarla betonarme yük yayma platformu arasındaki (geofoam blok-beton) ara yüzey ve geofoam bloklarla temel tesviye kumu arasındaki (geofoam blok-kum) ara yüzey dayanımları da yanal yüklere karşı tasarım aşamasında gerekmektedir. Daha önce geleneksel geofoam blok-geofoam blok ara yüzey davranışını iyileştirmek için ortaya konan dişli geofoam blok konseptinin bu çalışmada geofoam blok-beton ara yüzü mukavemetine olan etkileri araştırılmıştır. Bu kapsamda, malzeme yoğunluğunun ara yüzey gerilme-şekil değiştirme davranışına ve ara yüzey mukavemet parametrelerine olan etkilerini incelemek amacıyla iki farklı yoğunlukta (EPS19 ve EPS29), diş geometrisi ve sayısının etkisini belirlemek için ise iki farklı diş geometrisinde ve iki farklı diş sayısında geofoam bloklar kullanılmıştır. Ayrıca, tüm ara yüzey deneyleri hem yerinde dökme beton (geofoam blok-yerinde dökme beton) hem de prekast beton (geofoam blok-pürüzlü prekast beton) kullanılarak yapılmıştır. Ara yüzey kayma mukavemeti deney sonuçları her bir geometriye sahip ara yüzey gerilme-şekil değiştirme ve ara yüzey mukavemet parametreleri (ara yüzey sürtünme açısı, ve adhezyon, ca) üzerinden tartışılmıştır. Geleneksel geofoam blok-yerinde dökme beton çok kuvvetli ara yüzey adezyon mukavemetine sahiptir. Bu adezyon mukavemetinde dişli geofoam bloklar kullanılarak az da olsa iyileştirme sağlanmıştır. Bununla birlikte, geleneksel geofoam blok-pürüzlü prekast beton mukavemeti dişli geofoam blok konsepti sayesinde iyileşmiştir. Geleneksel otoyol dolgusu servis yükleri altında geofoam bloklardaki diş sayısındaki artış ile dişli geofoam blok-pürüzlü prekast beton ara yüzey mukavemeti geofoam blokların içsel mukavemetlerinin üzerinde elde edilmiştir. Dişli gefoam bloklar üzerine prekast betonarme yük yayma platformu inşası, yüksek yanal kuvvetlere maruz bölgelerde yapılacak geofoam otoyol dolgularında geleneksel geofoam blok üzerine yerinde dökme beton kullanılarak imal edilen yük yayma platformuna göre tercih sebebi olabilirler.
Interface shear strength properties between geofoam blocks (geofoam block-geofoam block) is a design parameter for the geofoam block highway embankments subjected to horizontal forces. In addition, interface shear strength properties in between the geofoam blocks in the last row of geofoam embankment and reinforced concrete load distribution slab (geofoam block-concrete) and geofoam blocks to bedding sand (geofoam block-sand) are also required for the design under horizontal forces. The effect of previously introduced interlocked geofoam block concept, which was developed to enhance interface shear strength properties of geofoam block to geofoam block, on geofoam block-concrete interface shear strength was investigated. For this purpose, two different geofoam blocks (EPS19 and EPS29) were used to investigate the effect of geofoam hardness on interface shear stress-strain characteristics, two different ledge geometries and two different numbers of ledges were used to investigate the affect of ledge shape and number of ledges, respectively. All interface shear strength tests were conducted using both cast in place concrete (geofoam block-cast in place concrete) and precast concrete (geofoam block-rough precast concrete). Interface shear strength test results were discussed in terms of interface shear stress –strain characteristics and interface friction properties (interface friction angle, and adhesion, ca) for each configuration. Traditional geofoam-cast in place concrete interface has strong adhesion strength. This adhesion strength has been slightly improved by using geofoam blocks with ledges. However, traditional geofoam block-rough cast in place concrete interface shear strength has been significantly improved by using geofoam block with ledges. Under the service loading of geofoam highway embankments, geofoam block with four triangle and four square ledges-rough precast concrete interface shear strength were obtained higher than that of internal shear strength of geofoam block. Using precast concrete panels as a load distribution slab on top of geofoam block with ledges can be a viable alternative for traditional cast in place reinforced concrete load distribution slab for the geofoam embankments subjected to high horizontal forces.
Interface shear strength properties between geofoam blocks (geofoam block-geofoam block) is a design parameter for the geofoam block highway embankments subjected to horizontal forces. In addition, interface shear strength properties in between the geofoam blocks in the last row of geofoam embankment and reinforced concrete load distribution slab (geofoam block-concrete) and geofoam blocks to bedding sand (geofoam block-sand) are also required for the design under horizontal forces. The effect of previously introduced interlocked geofoam block concept, which was developed to enhance interface shear strength properties of geofoam block to geofoam block, on geofoam block-concrete interface shear strength was investigated. For this purpose, two different geofoam blocks (EPS19 and EPS29) were used to investigate the effect of geofoam hardness on interface shear stress-strain characteristics, two different ledge geometries and two different numbers of ledges were used to investigate the affect of ledge shape and number of ledges, respectively. All interface shear strength tests were conducted using both cast in place concrete (geofoam block-cast in place concrete) and precast concrete (geofoam block-rough precast concrete). Interface shear strength test results were discussed in terms of interface shear stress –strain characteristics and interface friction properties (interface friction angle, and adhesion, ca) for each configuration. Traditional geofoam-cast in place concrete interface has strong adhesion strength. This adhesion strength has been slightly improved by using geofoam blocks with ledges. However, traditional geofoam block-rough cast in place concrete interface shear strength has been significantly improved by using geofoam block with ledges. Under the service loading of geofoam highway embankments, geofoam block with four triangle and four square ledges-rough precast concrete interface shear strength were obtained higher than that of internal shear strength of geofoam block. Using precast concrete panels as a load distribution slab on top of geofoam block with ledges can be a viable alternative for traditional cast in place reinforced concrete load distribution slab for the geofoam embankments subjected to high horizontal forces.
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İnşaat Mühendisliği, Civil Engineering