نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه سازه، دانشکده مهندسی عمران، دانشگاه صنعتی خواجه نصیرالدین طوسی، تهران، ایران
2 گروه سازه، دانشکده مهندسی عمران، دانشگاه صنعتی خواجه نصیرالدین طوسی، تهران، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Increased cracks caused by shrinkage are one of the problems associated with alkali-activated slag concrete as compared to ordinary Portland cement concrete, which can have destructive effects on the mechanical properties and durability of concrete. By adding fibers, the number of these cracks can be reduced, and their growth can be prevented. The purpose of this research is to investigate the effect of aggregate content and fibers on the mechanical properties (compressive strength, tensile strength, and flexural strength) of one-part alkali-activated slag concrete. To obtain the optimal aggregate ratio, three mixing designs with different aggregate ratios of 0.72, 0.75, and 0.78 were made and assessed. To investigate the effects of polypropylene (PP) and glass fibers on the mechanical properties of one-part alkali-activated slag concrete, PP fibers were used in three volume percentages of 0.15, 0.3, and 0.45 and glass fibers were used in two volume percentages of 0.15 and 0.30. The results showed that the aggregate ratio of 0.75 had the best performance among the other ratios. To make further samples containing fibers, the ratio of aggregate to the whole mixture was considered constant and equal to 0.75. Examining the results of the aforementioned tests showed that the high pH value in alkali-activated slag concrete can lead to a reduction in the tensile strength of glass fibers. Also, by increasing the concrete porosity due to the addition of glass fibers, the values of compressive strength, tensile strength, and flexural strength decrease. The bridging effect of PP fibers in concrete prevents the development and increase of crack width, which leads to the improvement of concrete performance in tensile and flexural strength. It should be noted that scanning electron microscope (SEM) images were prepared from samples containing PP fibers in order to investigate some results.
کلیدواژه‌ها [English]
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