Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Article Citation - WoS: 2Citation - Scopus: 3A New Method To Quantify the Robustness of Self-Consolidating Grouts(Elsevier, 2019) Erdem, Tahir Kemal; Bilgiç, Esra; Kanpara Cıvaş, ZüleyhaThere are different methods in literature to evaluate the robustness of highly fluid cementitious mixtures. However, no one of them gained widely acceptance due to the relative advantages and disadvantages involved in each of them. Therefore, there is still need for further research on this topic. This study proposes a new and relatively easy method for quantifying the robustness of self-consolidating grouts by calculating so-called robustness indices. Due to the more difficulty to produce robust mixtures for highly fluid mixtures obtained by very powerful chemicals, the method is based on the variations in the superplasticizer (SP) type and amount. Mineral admixture (fly ash or limestone powder) usage and water-to-binder ratio (w/b) were other parameters investigated in this study. It was found that SP type was the most important factor affecting the robustness. The effect of w/b was less when compared to SP type. The mixtures containing naphthalene-based SP were more robust than those containing polycarboxylate-based SP. Mineral admixture type and amount had the least effect on robustness. (C) 2019 Elsevier Ltd. All rights reserved.Article Citation - WoS: 81Citation - Scopus: 97Evaluation of Natural Zeolite as a Viscosity-Modifying Agent for Cement-Based Grouts(Elsevier Ltd., 2008) Şahmaran, Mustafa; Özkan, Necati; Keskin, Süleyman Bahadır; Uzal, Burak; Yaman, İsmail Özgür; Erdem, Tahir KemalThe effects of natural zeolite on the rheological and workability properties of the grout mixtures were studied. Setting times of grouts were also determined as part of the experimental study. For comparison, grout mixtures were also prepared with a commercially available viscosity modifying admixture (VMA). The experimental results show that addition of natural zeolite modifies both the rheological and workability properties of grouts. For a constant superplasticizer (SP) content, an increase in the zeolite amount significantly increases the yield stress, the apparent and plastic viscosity, and reduces the fluidity and deformability. Moreover, an increase in the amount of SP causes a significant reduction in both the yield stress and plastic viscosity of the grouts. It was also observed that, grouts prepared with natural zeolite addition have a pseudo-plastic behavior, and shear-thinning behavior increases with an increase in the zeolite amount. Therefore, it has been shown that using natural zeolite as a VMA it is possible to obtain grouts that have satisfactory rheological properties, especially if natural zeolite is used in combination with a superplasticizer.