Yazar "Atis, Cengiz D." seçeneğine göre listele

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    Öğe
    Fresh, Mechanical, Transport, and Durability Properties of Self-Consolidating Rubberized Concrete
    (Amer Concrete Inst, 2012) Karahan, Okan; Ozbay, Erdogan; Hossain, Khandaker M. A.; Lachemi, Mohamed; Atis, Cengiz D.
    This paper presents the fresh, mechanical, transport, and durability performances of self-consolidating rubberized concretes (SCRCs). Fresh concrete properties were determined with slump flow, V-funnel, J-ring, and L-box tests. Mechanical, transport, and durability properties were determined by measuring compressive, flexural, and splitting tensile strengths; bond strength characteristics; water porosity; water absorption; water sorptivity; rapid chloride-ion permeability; and freezing-and-thawing and corrosion resistance. SCRC mixtures with a water-binder ratio (w/b) of 0.32; total binder content of 500 kg/m(3) (842 lb/yd(3)); and crumb rubber content of 0, 10, 20, and 30% by fine aggregate volume were produced and tested. Fresh properties testing revealed that the use of crumb rubber as a fine aggregate diminished the filling and passing ability of SCRC. A gradual reduction in mechanical properties was also observed with an increase in crumb rubber content; however, the rate of compressive strength reduction was more evident than that of tensile strength. Despite the fact that water porosity, water absorption, and chloride-ion permeability increased slightly with the use of crumb rubber, a remarkable decrease was observed in the initial and secondary water sorptivity of SCRC. No significant decrease was observed in the freezing-and-thawing and corrosion resistance of SCRC with 10% crumb rubber. Beyond that level, however, durability performance was significantly affected.
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    Öğe
    Ground Granulated Pumice-Based Cement Mortars Exposed to Abrasion and Fire
    (Springer Heidelberg, 2017) Karahan, Okan; Hossain, Khandaker M. A.; Atis, Cengiz D.; Lachemi, Mohamed; Ozbay, Erdogan
    This study investigates the effect of ground granulated pumice (GGP) on workability, compressive/flexural strength and abrasion/fire resistance of mortars. Mortar mixture was prepared by replacing cement with GGP at five different replacement ratios (0, 5, 10, 15 and 20%). The sand-to-binder and water-to-binder ratios of the produced mortars were 3.0 and 0.50, respectively. Compressive/flexural strength and horizontal Bohme abrasion tests were conducted on mortar specimens at 28 days. Mortar specimens were also exposed to elevated temperatures of 300, 600 and 900 for a duration of 1 h to measure residual compressive strength. Test results showed that the use of GGP reduced the flow/workability of fresh mortars. It was also observed that the use of 10% GGP content slightly improved strength, abrasion and fire resistance of mortars compared to control normal Portland cement mortar.