Compressive strength and sulfate resistance of limestone and/or silica fume mortars

WOS: 000295754200073In this study, compressive strength and sulfate resistance of mortars containing silica fume and/or limestone in different replacement levels were examined. For this purpose, limestone was used as 5%, 20%, 35% and silica fume was used as 5%, 10%, 15% by weight of cement. Sixteen different blended cements were prepared containing limestone and/or silica fume in different ratios. Mortar mixtures were prepared using these 16 cements. Flow values and 2, 7, 28, 90, 180 day-compressive strengths of the mortar mixtures were determined. In addition, sulfate resistances of mortars were separately determined in sodium and magnesium sulfate solutions. Consequently, it was seen that negative effect of silica fume on workability of mortars and limestone on compressive strength of mortars can be compensated by using limestone and silica fume together. Simultaneous use of limestone and silica fume was showed to increase sulfate resistance of mortars. (C) 2011 Elsevier Ltd. All rights reserved

Usage of steel slag in concrete as fine and/or coarse aggregate

WOS: 000359502200013In this study, the use of steel slag as fine and/or coarse aggregate in concrete is investigated. For this purpose, 12 different concrete mixtures with different water/cement ratios of 0.40, 0.55 and 0.70 which include steel slag aggregate as fine and/or coarse aggregate are prepared. Compressive strength, split tensile strength, flexural strength, freeze-thaw resistance and water penetration depth of concrete mixtures containing steel slag aggregate are examined in comparison with concrete mixtures prepared by using crushed limestone aggregate. Eventually, concrete mixtures containing coarse steel slag show better performance than concrete mixtures containing limestone aggregate. Concrete mixtures containing fine steel slag show worse performance in comparison with concrete mixtures containing limestone aggregate.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107M607]This study was funded by the Scientific and Technological Research Council of Turkey (Project number: 107M607)

Effect of different curing conditions on flexural and compressive strength of fly ash mortars

WOS: 000443165200001In this study the effect of accelerated curing on the early flexural and compressive strengths of fly ash mortars were investigated. In the mortar mixtures CEM I 42.5 R type cement and C class C fly ash with different proportions were used. 40/40/160 mm prismatic specimens were prepared from these mortars. The mortar samples cured at 7 different curing conditions. Curing conditions are standard curing, 35 degrees C and 85 degrees C hot water curing. These curing conditions applied on specimens for different times. Flexural and compressive strengths were performed on the mortar specimens. Obtained test results were comparatively evaluated. The results of this study revealed that, early age strength gain under standard curing conditions due to fly ash inclusion can be compensated by accelerated curing

The effect of high temperature on the compressive strength of mortars

WOS: 000309493700014In this study, the effect of elevated temperature on the compressive strength of mortars containing fly ash, silica fume and pumice was investigated. Thirteen mortar mixtures were produced by replacing 0%, 5%, 10%, 15% and 20% of cement with a fly ash, silica fume and pumice. Totally, 3900 cube (50 x 50 x 50 mm) mortar specimens were prepared from these mortar mixtures and cured at 7, 28 and 90 days. After standard curing period. specimens were dried in a room temperature for 7 days and then exposed to temperature of 20, 150, 300, 450, 600 and 750 degrees C for 1 h in ceramic furnace. Afterwards, the compressive strengths of the specimens were determined. It was concluded that, compressive strengths of mortars containing pozzolan were less affected high temperature than that of control mortars. (C) 2012 Elsevier Ltd. All rights reserved

Prediction of mechanical and penetrability properties of cement-stabilized clay exposed to sulfate attack by use of soft computing methods

WOS: 000530789300002Similar 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.Ege University Science and Technology Centre-Technology Transfer Office (EBILTEM)Ege University [113M202, 2014-BIL-009]; Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [113M202, 2014-BIL-009]The authors appreciate contributions of the Scientific and Technological Research Council of Turkey (TUBITAK) and Ege University Science and Technology Centre-Technology Transfer Office (EBILTEM) under grant numbers 113M202 and 2014-BIL-009, and the support provided by Cimenta Group, Denizli Cimento A.S. and Akcansa for providing cements used in the experimental part of this study