Roller compacted concrete is a well-known new method in road construction and has been constantly evolving and improving. The concrete mix is made hsd with low slump and is compacted by a roller. Industrial slag obtained through metallurgical processes on mineral rocks because of environmental problems. Among these slags, we can mention copper slag, which is a sidelong product during the process of matte smelting and refining of copper. In this study, the effect of using copper slag on the mechanical properties and durability of roller concrete is investigated. The specimens used in this research are made based on the soil method and the Congo vibrating hammer is used for compaction. The necessary tests have been carried out in two stages. In the first stage, using two amounts of cementitious materials (12 and 15% by weight of dry aggregates), 4 amounts of slag (including 0, 20, 40 and 60% by weight of dry aggregates replaced with copper slag) and 5 different amounts of moisture (including 4, 4.75, 5.5, 6.25 and 7% by weight of aggregates and cementitious materials) have been investigated to determine the optimal moisture content required for the main mixing designs. At this stage of the experiment, 120 and 100mm cubic specimens were made and examined. Then, using the obtained optimum humidity, two values of cementitious materials and four values of copper slag replaced with rock materials of the main specimens were made. In the first stage experiments, the compressive strength of the specimens made with different humidity was obtained. Then, the experiments related to the original specimens made with the optimum moisture content were reviewed and eva‎luated. The specimens used in the compression tests at the age of 7 and 28 days include 48 cubic specimens of 100 mm and in the tensile tests at the ages of 7 and 28 days, they include 48 cylindrical specimens of 200 x 100 mm. In the bending test at the age of 28 days, they include 24 prismatic specimens of 100 x 100 x 350 mm, and the durability test contaning 150, 300 and 450 freeze and thaw cycles include 72 cubic specimens of 100 mm. In the permeability test, they include 24 cubic specimens of 120 x 200 x 200 mm, and in the 28-day water absorption test, they include 24 cubic specimens of 100 mm, and in the abrasian test, they include 14 circular slab specimens with a diameter of 600 and a thickness of 100 mm. on the base of obtained results, increasing the percentage of copper slag increases the volumetric weight and density of all designs. The highest mechanical strengths are in mix desgin containing 40% of copper slag, which in all specimens have greater strength than mix design without slag. With increasing copper slag and cement materials, water absorption decreases. Mix desgins containing 40% slag have the lowest penetration depth and mix designs containing 60% slag have the highest penetration depth compared to the control specimen. Also, increasing the cement content from 12 to 15% decreases the permeability. The greatest effect of concrete degradation has been observed in 150 freeze and thaw cycles. With increasing slag replacing natural aggregates, the abrasion depth of the roller compacted concrete in pavement is reduced, and the greatest reduction of the abrasion depth is observed in the mix designs containing 60% of copper slag.

كياچهر بهفرنيا

كياچهر بهفرنيا , محمدعلي رهگذر