Yazar "Yener E." seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The effects of silica fume and fly ash on the scaling resistance and flexural strength of pavement concretes(2011) Yener E.; Hinislioğlu S.The purpose of this study is to investigate the effects of Silica Fume (SF) and Fly Ash (FA) additives on the frost salt scaling resistance and flexural strength properties of pavement concrete. An attempt is also made to attain a more durable and higher strength concrete by a suitable combination of Ordinary Portland Cement (OPC), SF and FA. SF and FA are used as cement replacement in proportions of 0, 5, 10% and 0, 5, 10, 15% by weight respectively. Flexural strength is tested after 7, 28 and 91 days of the lime saturated water curing period. The experimental results indicate that using FA only decreases while SF only slightly increases 28-days flexural strength. On the other hand, using SF and FA together shows relatively more strength gain. Among all those tested, maximum 28 days flexural strength of 4.53 MPa is obtained for the mix proportions of 85% OPC + 10% FA and 5% SF. SF significantly decreases the amount of liquid absorption by capillary suction and has a significant effect on the scaling resistance. In addition, all the ternary mixtures showes better scaling resistance than the control mixture with 100% OPC. © 2011 Taylor & Francis Group, LLC. All rights reserved.Öğe The effects of silica fume and fly ash on the scaling resistance and flexural strength of pavement concretes(2011) Yener E.; Hinislio?lu S.The purpose of this study is to investigate the effects of Silica Fume (SF) and Fly Ash (FA) additives on the frost salt scaling resistance and flexural strength properties of pavement concrete. An attempt is also made to attain a more durable and higher strength concrete by a suitable combination of Ordinary Portland Cement (OPC), SF and FA. SF and FA are used as cement replacement in proportions of 0, 5, 10% and 0, 5, 10, 15% by weight respectively. Flexural strength is tested after 7, 28 and 91 days of the lime saturated water curing period. The experimental results indicate that using FA only decreases while SF only slightly increases 28-days flexural strength. On the other hand, using SF and FA together shows relatively more strength gain. Among all those tested, maximum 28 days flexural strength of 4.53 MPa is obtained for the mix proportions of 85% OPC + 10% FA and 5% SF. SF significantly decreases the amount of liquid absorption by capillary suction and has a significant effect on the scaling resistance. In addition, all the ternary mixtures showes better scaling resistance than the control mixture with 100% OPC. © 2011 Lavoisier, Paris.Öğe A new energy saving for the determination of mixing temperature in hot mix asphalts(2011) Yener E.; Hinislioglu S.The equi-viscous temperature range of asphalt has long been used in establishing the mixing temperature for mix designs and field production of hot mix asphalt (HMA). However, this method considers only binder viscosity to determine the mixing temperatures of the aggregate and asphalt. It is well known that depending on the gradation of aggregate and the type of plant and the mixing time. The appropriate mixing temperature for the proper coating may be lower than that of the viscosity based method. The excessive temperature causes the possible performance problems related to the hardening of the asphalt binder and increases the energy consumption, the gas emissions and fumes. In this study, a new method for the determination of asphalt-aggregate mixing temperature which considers the mixture properties was introduced to asphalt industry. The mixing temperatures of different nine mixtures were determined by both conventional and the proposed method. The effects of the nominal maximum aggregate size (NMAS), crushed coarse aggregate ratio (CCAR), the type of gradation, and the grade of binder on the mixing temperature were evaluated with an experimental study. Results show that decreasing NMAS, CCAR and increasing the grade of binder decreased the mixing temperature which is needed for proper coating. In addition, results showed that as going away from restricted zone of the Superpave gradation, the needed temperature to coat the aggregates decreased. The proposed method resulted in lower temperatures comparing to the conventional method on an average of 13°C. This means a possible energy saving of 14.3 x 10 9 kcal or 1362000 kg of crude oil in a year in Turkey. As a result, the new method is recommended due to not only the saving in energy but also decreasing the gas emissions and fume, and possible performance benefits. © Sila Science.Öğe A new frost salt scaling mechanism for concrete pavements based on brine rejection from ice layer adhered to concrete surface(Taylor and Francis Ltd., 2015) Yener E.In cold regions, highways, airfields or sidewalks are exposed to de-icing agents to thaw the ice layer on pavement surface. In this situation, a progressive surface damage that pulls off flaky chips from concrete pavement takes place. This damage is named as frost salt scaling. To produce scaling-resistant concrete and prevent the damage in the field, the deterioration mechanism should be understood well. For this aim, a number of mechanisms have been hypothesised in literature. However, there is no unique one which can be used to explain all observations from laboratory tests and field applications. In this study, a novel hypothesis that is built on earlier findings in literature is introduced. According to the proposed mechanism, the pressure applied by forced brine from outer strong ice layer, which adhered to surface, causes scaling in the strongly ice adhered regions. The published events that are unexplainable by a unique former mechanisms proposed in literature related to the frost scaling are rationalised based on the proposed mechanism. © 2014, © 2014 Taylor & Francis.
