Soğuk Derz Oluşan Beton Yüzeylerde Aderans Arttırıcı Katkıların Kayma Dayanımına Etkisinin İncelenmesi

Öz

Yapısal uygulamalarda çeşitli sebeplerle beton dökümünün tek aşamada tamamlanamamasından kaynaklı olarak oluşan soğuk derzler, zayıf arayüz nedeniyle betonarme elemanlarda önemli yapısal sorunlar meydana getirebilmektedir. Bu çalışmada, soğuk derz oluşumu nedeniyle zayıflayan kayma direncinin iyileştirilmesinde epoksi bazlı aderans arttırıcı katkıların ve yüzey hazırlığının etkinliğinin araştırılması amaçlanmıştır. Bu kapsamda, pürüzlü ve pürüzsüz yüzeylere sahip beton elemanlarda aderans arttırıcı katkı kullanılması ve kullanılmaması durumları ayrı ayrı deneysel olarak incelenmiştir. Üretilen numunelerin kayma performansı çift taraflı kayma deneyi yardımıyla belirlenmiş, kayma dayanımına ek olarak, kayma birim şekildeğiştirmesi, kayma rijitliği ve enerji yutma kapasitesi (tokluk) gibi parametreler de elde edilen sonuçlar ışığında analiz edilmiştir. Kayma dayanımı açısından yüzey pürüzlülüğü önemli bir etken olmakla birlikte, elde edilen bulgular, aderans arttırıcı katkı kullanımının bu dayanımı iyileştirmede daha etkin bir yöntem olduğunu ortaya koymuştur. Aderans arttırıcı katkı kullanılması ile birlikte, kayma dayanımında %192, kayma rijitliğinde %500, toplam enerji sönümleme kapasitesinde ise %227’ye varan artışlar elde edilmiştir. Çalışma sonucunda, aderans arttırıcı kullanımının pürüzsüz yüzeylerde dahi önemli katkı sağladığını, ancak yüzey pürüzlülüğü ile birlikte uygulandığında etkinin çarpan etkisiyle arttığını ve bu kombinasyonun soğuk derz oluşan beton yüzeylerde kayma performansını optimize ettiği sonucuna varılmıştır.

Anahtar Kelimeler

• Soğuk Derz
• Aderans Arttırıcı
• Epoksi Katkı
• Kayma Dayanımı
• Yüzey Pürüzlülüğü
• Çift Taraflı Kayma Deneyi

Investigation of the Influence of Bonding Agents on the Shear Performance of Cold Jointed Concrete Surfaces

Öz

Cold joints arising from interrupted concrete casting can weaken interfaces and cause significant structural issues in reinforced concrete elements. In this study, the aim was to investigate the effectiveness of epoxy-based bonding agents and surface preparation in improving the shear resistance weakened due to cold joint formation. Within this scope, the use and non-use of bonding agents on concrete elements with rough and smooth surfaces were experimentally examined. The shear performance was determined using a double-sided shear test, and parameters such as shear strain, shear stiffness, and energy absorption capacity (toughness) were analyzed in light of the results obtained, in addition to shear strength. While surface roughness is an important factor in shear strength, the findings revealed that the use of bonding-agent is a more effective method for improving this strength. With the use of bonding-agent, increases of up to 192% in shear strength, 500% in shear stiffness, and 227% in total energy absorption capacity were achieved. The study concluded that the use of bonding agents provides significant benefits even on smooth surfaces, but that the effect is multiplied when applied in combination with surface roughness, and that this combination optimizes shear performance on concrete surfaces with cold joints.

Anahtar Kelimeler

• Cold Joint
• Bonding Agents
• Shear Strength
• Adhesion İmprovement
• Surface Roughness
• Double-Sided Shear Test

Kaynakça

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