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Papers by Muhammed Durgun

Proceedings of the 2nd World Congress on Civil, Structural, and Environmental Engineering

Self-compacting concrete (SCC) is increasingly takes place in construction applications due to it... more Self-compacting concrete (SCC) is increasingly takes place in construction applications due to its excellent selfcompacting characteristic. It is known that, in order to achieve self-compacting feature, it is necessary to use high volume of fine materials in the mix design with effective superplasticizers. Using high volume of fine materials causes a decrease in the amount of total coarse aggregates. Coarse aggregates have an important role on the strength and elastic properties of concretes. This paper presents the results of an experimental study which investigated the strength and elastic properties of SCC mixtures modified with nano-SiO2. Nano-SiO2, having 35nm average particle size, was used with the aim of reducing the total fine material in SCC designs. Five different nano-SiO2 percentages (0.5%, 1.0%, 1.5%, 2.0% and 2.5%) were utilized and the total fly ash content used in the reference mixture was gradually reduced. The volumetric emptiness occurred by the fly ash reduction was filled by aggregates. Successful mixtures which exhibited desired SCC properties were subjected to compressive tests at 28 th and 120 th days. Moduli of elasticity of concrete specimens were also measured. Results have shown that with increasing W/Cm ratio, compressive strengths were decreased. The use of nano-SiO2 in reduced-fly ash content mixtures could not compensate the strength decrement. However, the use of nano-SiO2 combined with fly ash has prominently enhanced the elastic modulus of nano-modified SCC mixtures.

Proceedings of the 2nd World Congress on Civil, Structural, and Environmental Engineering, 2017

Self-compacting concrete (SCC) is one of the most important developments in construction industry... more Self-compacting concrete (SCC) is one of the most important developments in construction industry. SCC mix design has differences from conventional concrete mix design in order to obtain self-compacting ability. These mixtures necessitates the use of powerful superplasticizers, smaller maximum aggregate size, higher amount of fine materials, and lower water/binder ratio mixtures. Using high amount of fine materials causes a reduction in total coarse aggregate content. This reduction causes changes in elastic properties of hardened concrete. In this study, Nano SiO2, which is a nano-technological material having enormous specific surface area, was used with the aim of reducing the total fine material amount in the mix design. Therefore, fly ash, which was used as fine material, was reduced gradually. The volumetric emptiness occurred by this reduction was filled with aggregates. Two different sizes of nano SiO2 with the average particle diameters of 35 nm and 17 nm were used. Five different percentages of nano SiO2 samples were selected as 0.5%, 1.0%, 1.5%, 2.0% and 2.5%. In order to understand the fresh properties T500, slump flow diameter, V-funnel and sieve segregation tests were performed. The results of these test indicated that the use of nano SiO2 would be an effective method in order to reduce the total fine material amount of SCC mixtures.

Construction and Building Materials, 2021

Abstract In this study, the properties of gypsum-based pastes and mortars containing recycled til... more Abstract In this study, the properties of gypsum-based pastes and mortars containing recycled tile powder were investigated at ambient and high temperatures. For this purpose waste tiles were collected from demolition sites and ground. Two different sample groups, namely gypsum pastes and gypsum mortars, were produced. Both groups had their own reference sample that was produced using only gypsum, in addition to samples that were modified by using 10%, 20% and 30% recycled tile powder. The samples were exposed to 600 °C and 800 °C. Unit weights, mass losses, ultrasonic pulse velocities, bending strengths, compressive strength, volume changes and visual investigations were performed on the samples before and after they were exposed to the high temperatures. In addition, the apparent porosity, water absorption and thermal conductivity of the recycled tile powder containing gypsum-based mixtures were investigated. In order to investigate the microstructural changes of the mixtures, scanning electron microscopy examinations and XRD analyses were performed. The findings showed that the strength of the mixtures decreased with the addition of recycled tile powder. The apparent porosity and water absorption of the mixtures were found to increase. However, the presence of recycled tile powder enhanced mass loss, thermal conductivity and high temperature resistance. Furthermore, the volume changes resulting from high temperatures were significantly reduced by using the recycled tile powder.

European Journal of Technic, 2019

The wastes generated by the recent industrial developments threaten the future of the world. Ther... more The wastes generated by the recent industrial developments threaten the future of the world. Therefore, researches on the recycling of the industrial wastes in various ways are increasing day by day. In this study, glass powder, a waste of glass industry, colemanite ore waste, a by-product of boron industry and filter cake, one of the wastes of sugar factories, were used. The evaluation of these wastes in gypsum and lime based mortars has been investigated. In this study, 10, 20 and 30% of the waste materials were used instead of gypsum. Unit weights, ultrasonic pulse velocities, apparent porosities and thermal conductivity coefficients of the gypsum-lime based mortars were determined. Compressive strength and bending strength tests were performed to determine the mechanical properties. The results indicated that the use of wastes negatively affected the mechanical properties while improving the thermal properties.

Construction and Building Materials, 2018

h i g h l i g h t s In an effort to reduce the total fine material content in SCC, CNS was utiliz... more h i g h l i g h t s In an effort to reduce the total fine material content in SCC, CNS was utilized. Elastic moduli of SCCs with CNS have been significantly improved. Concerns due to lower stiffness of SCC can be overcome with the use of CNS. Use of FA and CNS together eliminates ITZ phase due to effective densification.

Construction and Building Materials, 2017

h i g h l i g h t s In an effort to reduce the total fine material content in SCC, CNS was utiliz... more h i g h l i g h t s In an effort to reduce the total fine material content in SCC, CNS was utilized. CNS usage is an effective method in reducing fine material content of SCC mixtures. Lowering the particle size of CNS, strengthens its effectiveness on fresh properties.

Construction and Building Materials, 2020

h i g h l i g h t s Non-standard fly-ash evaluated as geopolymer raw material with silica sources... more h i g h l i g h t s Non-standard fly-ash evaluated as geopolymer raw material with silica sources. A new utilization field investigated for unused waste fly ash. Waste glass powder and silica fume utilized as high-silica sources. Geopolymer properties were improved by using high-siliceous materials.