جستجوی مقالات مرتبط با کلیدواژه « سرباره کارخانه فولاد اهواز » در نشریات گروه « فنی و مهندسی »

Seven mixing plans with, 20%, 30%, 40%, 50%, 60% and 70% of slag in powdered form replaced part of the cement and the specimens were made at the ages of 28, 56, 91 and 120 days. They were subjected to the necessary tests. Slump tests, specific weight of fresh concrete, compressive strength, tensile strength of halving, electrical resistance, volumetric water absorption and depth of water penetration of the specimens made from reference concrete and cement-slag were performed. The results showed that the slag powder had no significant effect on mechanical properties of the specimens until the age of 56 days, but with the passage of time, the compressive strength of the specimen containing 40% slag at the age of 120 days was 1% compared to the reference specimen. In terms of tensile strength, specimens containing 30% slag at the age of 120 days showed an increase of 4% compared to the reference specimen; although the increase of 1% seems insignificant, but it indicates that until the age of 120 days, the slag has a positive effect on compressive strength, it is worth mentioning. The percentage of water absorption at the age of 120 days in the specimen containing 40% slag showed an increase of 3.4% compared to the reference specimen. In addition, the electrical resistance of the specimen containing 40% slag at the age of 120 days decreased by 37% and the water penetration depth in the specimen containing 40% slag increased by 2.8 mm compared to the reference specimen.

Wastes and by-products of industrial plants can be useful in road construction. One of these wastes is the slag of Ahvaz steel plant, which produces about one million tons per year. The lack of riverbeds and aggregates in country, especially in Ahvaz, is hampering construction projects and increasing construction costs in these areas. All construction projects in Ahvaz are made of non-renewable river or mountain materials. Slag is one of these materials that can be a useful replacement for river or mountain materials. The high utilization of lime-based materials for bed consolidation in road infrastructure has led this study to investigate the use of slag as a substitute for Kopal-Lime mixture in road construction. In this study, a thorough review of the use of slag as a substitute for natural materials from viewpoint of quality, time, cost and environmental protection is undertaken. It was found that the bearing strength in the saturated mixture containing 70% slag and 30% soil was increased by 62% compared to of kopal-lime mixture application with a concentration of 150 kg/m3, and 30% in the dry mix condition. The Rial estimate for project implementation as per Cost List 1398 with a mixture containing 70% slag and 30% soil was reduced by 65% compared to the Kopal-Lime mixture. The optimal mix design time is 80% less than the kopal-lime mixture. Overall, the results are remarkable from a qualitative and economic viewpoint, so the use of slag as a substitute for river materials is strongly recommended.

With the use of pozzolans and additives, today, a huge change has been made in mortar technology to achieve high strength and durability. The purpose of this study is to make two-component and three- component mortars and compare their rheological and mechanical properties. In this research, compressive, flexural and tensile strength tests were performed on reference mortar, two-component mortars as well as three-component mortars. Slag utilized in making of research mortars was produced in Ahvaz Steel plant. Compressive strength tests were conducted at 7, 28, 56 and 91 days and flexural and tensile strength tests were performed at 28 and 91 days. In the mentioned resistance tests, cubic specimens with dimensions of 50 mm, prismatic specimens with dimensions of 160 × 40 × 40 mm and standard bow-tie specimens were applied, respectively. The results presented that the replacement of microsilica up to 10% by weight of cement increased the compressive, flexural and tensile strengths of two-component mortars, which were significant at all ages compared to the sample without microsilica. With increasing cement substitute microsilica up to 15%, changes in compressive, flexural and tensile strengths follow an inverse nonlinear behavior. Optimal microsilica and slag replacement percentages of 5% and 10%, respectively, increased the three strengths in the three-component mortars, which are significant at all ages compared to the reference sample. With increasing the percentage of replaced microsilica, the flowability of the mortars decreased and with increasing the percentage of slag, the flow increased.