Browsing by Author "Mardani-Aghabaglou, Ali"
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Publication Durability performance and dimensional stability of polypropylene fiber reinforced concrete(College Publishing, 2018-03-01) Mardani-Aghabaglou, Ali; Özen, Süleyman; Altun, Muhammet Gökhan; MARDANİ, ALİ; Özen, Süleyman; Altun, Muhammet Gökhan; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü; 0000-0003-0326-5015; 0000-0001-5522-427X; C-7860-2015; AAJ-6415-2021; AAM-9495-2020; CBF-4437-2022In this study, the durability performance and dimensional stability of polypropylene fiber reinforced concrete mixture were investigated. For this purpose, two series of concrete mixtures, including a 0.45 water/cement ratio was prepared both in the absence and presence of fiber. A CEMI 42.5 R type portland cement and crushed limestone aggregate with a maximum particle size of 25 mm were used. In addition to the control mixture without fiber, three different concrete mixtures were prepared by adding polypropylene fiber as 0.4%, 0.8% and 1% of total volume into the mixture. The time-dependent fresh state properties, strength, ultrasonic pulse velocity, transport properties, drying shrinkage and freeze-thaw resistance of concrete mixtures, sodium sulfate attack and abrasion were investigated comparatively. Test results demonstrated that utilization of fiber affected the fresh properties of the concrete mixtures negatively. However, the 0.8% fiber-bearing mixture showed the highest performance in terms of durability and dimensional stability. Beyond this utilization ratio, the durability performance of the concrete mixture was negatively affected. The risk of nonhomogeneous dispersion of the fiber in the mixture was relatively high in the excess fiber-bearing mixture. Consequently, with the formation of flocculation in the mixture the void ratio of concrete mixture increased.Publication Durability performance and dimensional stability of road concrete containing dry-shake surface hardener admixture(Elsevier, 2021-03-08) Mardani-Aghabaglou, Ali; Karakuzu, Kemal; Kobya, Veysel; Hatungimana, Daniel; MARDANİ, ALİ; Karakuzu, Kemal; Kobya, Veysel; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği; 0000-0003-0326-5015; 0000-0002-1023-3962; FEQ-9214-2022; GBH-3020-2022; C-7860-2015Durability and dimensional stability problems are emerged in road concrete due to traffic loads and environmental factors. The concrete surface treatment is one of the preferred methods to solve these problems economically. As it is known, surface treatment is applied to the concrete surface as dry-shaking and liquid. It is understood from the literature that there are very limited studies about the use of dry-shake hardener admixture in concrete mixtures. In the present study, the effect of dry-shake surface hardener admixture application on mechanical, durability and dimensional stability properties of concrete mixtures having different w/b ratios were investigated. Totally ten series of concrete mixtures coated with and without dry-shake surface hardener admixture were prepared for this purpose. The slump value of concrete mixtures was determined as 85 +/- 5 mm. Vebe, slump and air content tests were performed for each mixture in fresh state and unit weights of mixtures were calculated. Also, compressive strength, modulus of elasticity, transport properties, abrasion resistance, freeze-thaw resistance and drying shrinkage behavior were investigated on the 7, 28 and 90-day specimens. In the light of the experiment results, compressive strength, modulus of elasticity, water sorptivity, abrasion resistance and drying shrinkage behavior of concrete mixtures were positively affected with adding of dry-shake surface hardener admixture. However, it was found that the dry-shake surface hardener admixture application had no significant effect on water absorption, depth of water penetration under pressure and freezing-thawing performances. (C) 2020 Elsevier Ltd. All rights reserved.Publication Effect of high temperature on polypropylene fiber-reinforced mortars containing colemanite wastes(Elsevier, 2021-11-23) Durgun, Muhammed Yasin; Özen, Süleyman; Karakuzu, Kemal; Kobya, Veysel; Bayqra, Sultan Hüsein; Mardani-Ağhabağlou, Ali; Karakuzu, Kemal; Kobya, Veysel; Bayqra, Sultan Husein; Mardani-Aghabaglou, Ali; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0003-0326-5015 ; 0000-0002-1023-3962; GBH-3020-2022 ; FEQ-9214-2022 ; CDR-7456-2022 ; C-7860-2015In this study, the effect of polypropylene (PP) fiber utilization ratio on the fresh and some hardened properties of mortar mixtures containing colemanite waste (CW), which mainly contains B2O3, SiO2 and CaO, containing mortar mixtures were investigated. The 17 mortar mixtures were prepared by replacing 0, 1, 3, 5, and 7 wt% of cement with CW and by adding 0, 0.5, 0.75, and 1% by volume of PP fibers to the control mixture. In all mixtures, water/binder ratio, sand/binder ratio and slump-flow values were kept constant as 0.485, 2.75 and 220 +/- 20 mm, respectively. Water reducing admixture requirement of each mixture was determined to provide the target slump-flow range in mortar mixtures. There was a change in the amount of admixture according to the amount of CW and fiber content in the mixture. The 28 and 56-day water absorption capacity, compressive strength and high temperature resistance of mortar mixtures were determined. Strength reduction of specimens exposed to 300 degrees C and 600 degrees C were compared. In addition, thermal and scanning electron microscopy (SEM) analyses were performed on the specimens. According to the test results, with the increase in the amount CW and PP fiber in the mixtures, the admixture demand to provide target flow value and the 28-day water absorption capacity of the mixtures increased, while the 28-day compressive strengths decreased. However, while there was no significant change in the 56-day water absorption capacity and compressive strength values of the specimens containing CW, the water absorption capacity increased and the compressive strength decreased upon the presence of fiber in the matrix. The specimens containing both of CW and PP fiber showed better performance in terms of high-temperature resistance.Publication Effect of main and side chain length change of polycarboxylate-ether-based water-reducing admixtures on the fresh state and mechanical properties of cementitious systems(Wiley-Blackwell, 2020-10) Özen, Süleyman; Ramyar, Kambiz; Altun, Muhammet Gökhan; Mardani-Aghabaglou, Ali; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi /İnşaat Mühendisliği Bölümü; 0000-0002-9345-9907; 0000-0003-0326-5015; C-7860-2015; CBF-4437-2022; 57203431200; 57669486700In this study, the effect of both main and side chain length changes of the admixtures on some properties of cementitious systems were investigated. Three different polycarboxylate-ether-based water-reducing admixtures (WRA) having constant molecular weights and different main and side chain lengths were synthesized. Single type of raw material and carboxylate functional group were used in all WRAs. The molecular weights, free nonionic contents, and anionic/nonionic ratios of the admixtures were kept constant. Test results showed that degree of fluidity was observed in cement paste and mortar mixtures in case the admixture main and side chain length is more or less than a critical value. This negative effect is thought to be due to the weakening of the adsorption ability by the chain length change of the admixtures, the being tendency of polymers to intertwine and the adsorbing of admixture on several cement particles simultaneous. Admixtures having excessive long or short main chain and side chain improved the time-dependent slump-flow retention of the mortar mixtures. The admixtures with short main and side chains had insufficient adsorption ability and the admixture with excessive long main and side chains had the interlacing risk of polymers. In both cases, time-dependent behavior improved because the amount of free admixture in solution increased. The change in the chain lengths of the WRAs affected the 1-day compressive strength of the mortar mixtures.Item The effect of shrinkage reducing admixture and polypropylene fi bers on drying shrinkage behaviour of concrete(Stowarzyszenie Producentow Cementu, 2019-05) Mardani-Aghabaglou, Ali; İlhan, Metin; Özen, Süleyman; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0003-0326-5015; 0000-0001-5522-427X; 0000-0003-0326-5015; C-7860-2015; AAJ-6415-2021; AAM-9495-2020; 57669486700; 55427677700; 57188750603The paper presents comparative studies on the impact of polypropylene fibers and commercial shrinkage reducing admixture on the drying shrinkage, water absorption, as well as compressive strength of concrete. Concretes with a constant cement content, water/cement ratio and consistency with the addition of admixture and fibers tested separately as well as introduced together were tested. The obtained results showed that the addition of fibers increases the need for a superplasticizing admixture in order to obtain the assumed consistency. The use of shrinkage reducing admixture and polypropylene fibers has a positive effect on the compressive strength and the permeability of concrete. Both the shrinkage reducing admixture as well as the fibers have reduced the drying shrinkage of the concrete. The impact of fibers on shrinkage was greater than the impact of the admixture. Regarding the drying shrinkage, the experimental results showed that the simultaneous addition of shrinkage reducing admixture and polypropylene fibers did not show a beneficial effect, on the contrary, it only caused an increase in costs.Publication Effects of material properties on the mechanical and durability behaviors of khorasan mortar mixtures: A review(Taylor, 2021-03-05) İsafça, Tuğçe; Karakuzu, Kemal; Özen, Süleyman; Doğangün, Adem; Mardani-Aghabaglou, Ali; İsafça, Tuğçe; Karakuzu, Kemal; DOĞANGÜN, ADEM; MARDANİ, ALİ; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü; 0000-0002-9331-1339; 0000-0002-1023-3962; 0000-0002-1867-7103; 0000-0003-0326-5015; AAR-6126-2020; C-7860-2015; GBH-3020-2022; GFM-1667-2022Historical buildings are an important piece of our cultural heritage. It is important that the materials used in the preservation, repair and reinforcement applications of these structures should be compatible with the existing structure. In many of the historical buildings in Turkey, it was reported use of the Khorasan mortar as the masonry mortar and plaster. Khorasan mortar contains slaked lime as a binder, river sand, and clayey materials as aggregate, which are fired at high temperature. It was emphasized that this mortar is an essential building material widely used in the construction and repair of historical buildings from past to present. In this study, the effects of binder, aggregate, chemical admixture, organic admixture, and fiber properties on the mechanical and durability performance of Khorasan mortar and lime-based mortar mixtures were investigated. For this purpose, a comprehensive literature research was carried out on this subject. In addition, the positive and negative effects of these materials on the mortar mixture were emphasized.Publication Prediction of mechanical and penetrability properties of cement-stabilized clay exposed to sulfate attack by use of soft computing methods(Springer, 2020-05-06) Sezer, Alper; Sezer, Gözde Inan; Mardani-Aghabaglou, Ali; Altun, Selim; Mardani-Aghabaglou, Ali; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü; 0000-0003-0326-5015; C-7860-2015; AAJ-6415-2021Similar to its effects on any type of cementitious composite, it is a well-known fact that sulfate attack has also a negative influence on engineering behavior of cement-stabilized soils. However, the level of degradation in engineering properties of the cement-stabilized soils still needs more scientific attention. In the light of this, a database including a total of 260 unconfined compression and chloride ion penetration tests on cement-stabilized kaolin specimens exposed to sulfate attack was constituted. The data include information about cement type (sulfate resistant-SR; normal portland (N) and pozzolanic-P), and its content (0, 5, 10 and 15%), sulfate type (sodium or magnesium sulfate) as well as its concentration (0.3, 0.5, 1%) and curing period (1, 7, 28 and 90 days). Using this database, linear and nonlinear regression analysis (RA), backpropagation neural networks and adaptive neuro-fuzzy inference techniques were employed to question whether these methods are capable of predicting unconfined compressive strength and chloride ion penetration of cement-stabilized clay exposed to sulfate attack. The results revealed that these methods have a great potential in modeling the strength and penetrability properties of cement-stabilized clays exposed to sulfate attack. While the performance of regression method is at an acceptable level, results show that adaptive neuro-fuzzy inference systems and backpropagation neural networks are superior in modeling.Publication Recycling of sewage sludge incineration ashes as construction material(Gazi Üniversitesi Mühendislik Mimarlık Fakültesi, 2020-01-01) Yiğit, Berna; Salihoğlu, Güray; Mardani-Aghabaglou, Ali; Salihoğlu, Nezih Kamil; Özen, Süleyman; Yiğit, Berna; SALİHOĞLU, GÜRAY; MARDANİ, ALİ; SALİHOĞLU, NEZİH KAMİL; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Çevre Mühendisliği Bölümü; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü; 0000-0003-0714-048X; 0000-0003-0326-5015; AAG-9399-2021; AAG-9413-2021; AAJ-6415-2021; C-7860-2015; EHO-7411-2022Sewage sludges that are originating from the municipal wastewater treatment plants of Bursa city have been incinerated with a fluidized bed reactor of 400 tons/day capacity since 2017. Each month, on an average, 615 tons of ash is generated as a waste of the incineration process, which needs disposal. The purpose of this study was to investigate if the sludge incinerator ash can be recycled as a construction material. Stabilization/solidification (S/S) and geopolymerization technologies were applied to the sludge ash with this aim. Portland cement, fly ash from a coal-fired power plant, and marble sludge were used as binders. S/S samples were activated with water, while geopolymer samples were activated with 8MNaOH and NaSilNaOH solutions. The prepared paste samples were air-cured for 28 days and analyzed for compressive strength and heavy metals leaching. S/S samples containing sludge ash yielded a compressive strength level of 21.8 MPa, while geopolymer samples resulted in a compressive strength level of 50.0 MPa. Higher compressive strength levels of several samples containing waste sludge ash than that of the control samples without waste were noticed. Leaching tests showed that heavy metals leaching from the samples prepared with sludge ash were much lower than the legal limit values for toxicity. Both leaching tests and compressive strength tests showed that sludge ash has the potential to be considered as a construction material.Publication Specimen size and shape effects on strength of concrete in the absence and presence of steel fibers(Pontificia Univ Catolica Chile, Escuela Construccion Civil, 2021-04-01) Nobakhtjoo, Amir; Mardani-Aghabaglou, Ali; MARDANİ, ALİ; Bayqra, Sultan Husein; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi.; 0000-0003-0326-5015; AAJ-6415-2021; C-7860-2015In this research, the effects of size and shape on compressive and splitting tensile strength of fibrous and non-fibrous concrete specimens with different characteristic strength were investigated. With this aim, both fibrous and non-fibrous 10 different concrete mixtures with 0.3, 0.4, 0.5, 0.6 and 0. 7 Water/Cement ratio were prepared. In the fibrous mixture specimens, the total amount of steel fibers to 1% by total volume. In the entire specimens, 42.5 R type Portland cement were used as bonding elements while crushed lime stones in 3 sizes were added to the mixtures. Furthermore, to evaluate the influence of size and shapes over specimens' strength, for each concrete mixtures two 10 cm and 15 cm cubic specimen beside two 10x20 cm and 15x30 cm cylindrical specimens were prepared as well. The prepared specimens were subjected to compressive and splitting tensile tests. The results showed that, regardless of the fiber amount and specimens' shapes, the decrease in specimens' size resulted in higher strength. But in the high ratio of Water/Cement and fibrous mixtures, the mentioned behavior was not observed.Item Transport properties and freeze-thaw resistance of mortar mixtures containing recycled concrete and glass aggregates(Taylor & Francis, 2016-11-15) Beglarigale, Ahsanollah; Yazici, Halit; Ramyar, Kambiz; Mardani-Aghabaglou, Ali; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği Bölümü.; 0000-0003-0326-5015; AAJ-6415-2021; 57669486700The effects of recycled glass (RG) and recycled concrete (RC) fine aggregates on the compressive strength, ultrasonic pulse velocity, dynamic elastic modulus, transport properties and freeze-thaw resistance of mortar mixture were investigated comparatively. Nine different mortar mixtures were prepared by partial replacement of crushed-limestone fine aggregate with recycled aggregates. Compared to that of the control mixture, the transport properties of RC aggregate-bearing mixtures inversely affected with increasing the replacement level of this aggregate. The opposite results were obtained in RG aggregate-containing mixtures. Frost resistance of mortar mixture improved by using both of the recycled aggregates. Improvement of frost resistance of RC mixtures was attributed to the presence of improved Interfacial transition zone between matrix and coarse aggregate (ITZ) in RC-bearing mixture and to the high number of pores existing in the well-distributed RC aggregates in the mixture. Perhaps, these pores provide additional sites for the water escaped from capillary pores upon ice formation.