بررسي مقاومت فشاري بتن هاي ساخته شده از سرباره كارخانه ذوب آهن اصفهان و نحوه بهبود مقاومت فشاري آنها

Investigation of Compressive Strength of Concretes Containing Isfahan Blast Furnace Slag and Procedure of their Compressive Strength Improvement

Researches show that concretes containing 25 to 35 % slag powder (as alternation for Protland cement) obtain compressive strength CS about 85% and 97% of the control specimens (without slag) at the ages of 28 and 90 days respectively. These concretes, also, recorded less growth rate of the CS than the control specimen at early ages (< 28 days). In order to increase the early CS of these concretes and acquire 28-days old CS about control specimens, this investigation was carried out using various percentage of the silica fume replaced with known quantities of Prortland cement. The results revealed that specimens containing 5% silica fume along with 25 to 35% slag powder displayed 5.2% and 13.3% higher than CS of control specimens at the 28 and 90 days respectively. In other part of the study the CS of the concretes containing slag powder cured with water comprising 2.5% MgSo4 as well as 2.5% NaCl were evaluated. Slag-contained specimens, which were placed in above mentioned curing situation, showed less CS at 28 days than control specimens where as at the age of 90 and 180 days CS of the specimens were higher than the control specimence. The 25% slag-contained speciemens placed in sulphated situation at 180 day old stage showed 325 Kg/cm2 CS which was 14.44% higher than the control sample attaining the best result, here with material and geometric nonlinear analysis. In this paper, buckling behavior and ultimate capacity of built up castellated compound columns are investigated using ANSYS software. A brief of results is reported on for a number of CPE sections in different boundary conditions. Also is presented slenderness-load curve by using of Jandel software, which is a useful tool for investigation of ultimate capacity of the columns.