Investigating the effect of surplus filler of asphalt plant on setting time and compressive strength of cement mortar

The setting of cement is a parameter by it, factors such as mix operations, transporting, casting, density and surface repair can be controlled. Concrete properties directly correlate with the type and amount of the cements present in the concrete and affect compressive strength, which is one of the factors presenting concrete quality. In this study, effect of zero to 50% replacement of cement by surplus filler of asphalt plant was investigated with the aim of reducing cement consumption. To this aim and in the first step, the optimum water content of the cement paste was obtained by using a 10mm needle of Vicat apparatus. Then, the effect of adding filler in different amounts on the initial and final setting of the cement paste was evaluated. By constructing 110 cubic specimens with the size of 100 mm, with constant mix design of water and sand, the compressive strength of the cement mortar containing filler at 3, 7, 28, 56 and 90 days was obtained with specified replaced percentages of filler at 20 degrees C. Moreover, the growth rate of compressive strength was examined in 0 and 20% replacement of cement by filler at the ages of 1, 3, 7, 14, 28, 56 and 90 days at 35 degrees C. According to the results, adding the filler is a factor of delaying the initial and final setting time. The filler increment in the cement mortar leads to a drop in the compressive strength. However, this reduction is negligible when the filler percentage is less than 15%.