DETERMINATION OF MOISTURE SUSCEPTIBILITY CHARACTERISTICS OF POLYMER MODIFIED HOT-MIXED ASPHALT

Abstract

Many highway agencies have been experiencing premature failures that decrease the performance and service life of pavements. One of the major causes of premature pavement failure is the moisture damage of the asphalt concrete layer. Many variables affect the amount of water damage in the asphalt concrete layer such as the type of aggregate, bitumen, mixture design and construction, level of traffic, environment and the additive properties that are introduced to the bitumen, aggregate or bitumen aggregate mixture. This study is aimed to determine the effect of additives such as elastomeric (SBS) and plastomeric (EVA) polymer modified bitumen (PMB) on the stripping potential and moisture susceptibility characteristics of hot mix asphalt (HMA) containing different types of aggregate (basalt-limestone aggregate mixture and limestone aggregate). The stripping properties and moisture susceptibility characteristics of the samples have been evaluated by means of captured images and the Nicholson Stripping Test (ASTM D 1664) as well as the Modified Lottman Test (AASHTO T 283) respectively. The results indicated that polymer modification increased the resistance of asphalt mixtures to the detrimental effect of water. Moreover, it was found out that samples prepared with SBS PMB exhibited more resistance to water damage compared to samples prepared with EVA PMB

Keywords

• Polymer modified bitumen, Stripping, Water damage, Moisture susceptibility

POLİMER MODİFİYE BİTÜMLERLE ELDE EDİLEN SICAK KARIŞIMLARIN SUYA KARŞI DUYARLILIKLARININ İNCELENMESİ

Abstract

Yol kaplamalarının servis ömrünü ve performansını düşüren erken bozulmalar üzerine birçok çalışma yapılmıştır. Kaplamaların öngörülen süreden daha erken bozulmalarının en büyük sebeplerinden biri de bitümlü kaplamalardaki suya bağlı bozulmalardır. Agrega cinsi, bitümlü bağlayıcı, karışım tasarımı ve yapımı, trafik düzeyi, çevre, bitüme ve/veya agregaya eklenen katkıların özellikleri gibi birçok etken bitümlü kaplamalardaki suya bağlı bozulmaların miktarını etkiler. Bu çalışmanın amacı, elastomerik (SBS) ve plastomerik (EVA) polimer modifiye bitümlerle (PMB) hazırlanan ve farklı agrega türleri (bazalt-kalker agrega karışımı ve yalnız kalker agregası) içeren sıcak karışım asfaltların soyulma potansiyeli ve neme karşı duyarlılık özelliklerinin saptanmasıdır. Hazırlanan örneklerin bu özellikleri, Nicholson Soyulma Deneyi (ASTM D 1664) ve Modified Lottman Test (AASHTO T 283) deneylerinden elde edilen bulgular ile Leica S 8 AP0 Stereo Mikroskobu kullanılarak elde edilen mikroskobik görüntüler yardımıyla değerlendirilmiştir. Deneysel sonuçlar, elastomerik ve plastomerik polimer modifikasyonların suyun asfalt karışımlar üzerindeki etkisini azalttıkları ve kaplamanın neme karşı direncini arttırdıkları göstermiştir. Ayrıca yapılan çalışmalardan elde edilen verilere göre, SBS PMB ile hazırlanan karışımların EVA PMB ile hazırlanan örneklere göre suya karşı bozulmalar üzerine etkisinin daha fazla olduğu saptanmıştır

Keywords

• Polimer modifiye bitüm, Soyulma, Suya bağlı bozulmalar, Neme karşı hassasiyet

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