Akademik Veri Yönetim Sistemi
7th Asian Symposium on Polymers in Concrete (ASPIC 2012), İstanbul, Türkiye, 3 - 05 Ekim 2012, ss.509-516, (Tam Metin Bildiri)
In this paper, the evaluation of the bond behavior of polymer modified alkali resistant (AR) glass yarns embedded in cement matrix is presented. The multifilament AR-glass yarns were extracted from a warp knitted fabric and modified by two types of slurries containing polystyrene and styrene acrylic polymers which are non-film forming and film forming, respectively. Two types of pull-out sample preparation methods (namely wet and dry processes) have been applied before the incorporation of modified yarns into the cement paste. Unmodified and polymer modified yarns were embedded on one side in a cement paste matrix of 0.40 water to cement ratio and in the other in a polyester matrix grip for pulling out of the yarns from the cement paste matrix. The bond behavior of unmodified and polymer modified AR-glass yarns were evaluated by the pull-out load displacement relationship and in-situ breakage of filaments during pull-out, and its quantification in terms of the proportion of filaments broken at each stage of pull-out. For that purpose a special set up was used based on the transmission of light through unbroken filaments and quantification by image analysis. All test procedures have also been applied to aged samples to find out the effectiveness of microstructure modification on long-term properties. The test results revealed that polymer modification of the microstructure of AR-glass yarns has a significant effect on the bond properties. As a result the relatively brittle failure characteristic of unmodified AR-glass yarns could be turned into a less brittle controlled telescopic pull-out mode. The effectiveness of polymer modification was found to be highly dependent on the polymer type and the nature of the treatment of the yarns with the polymer slurry.