نوع مقاله : علمی - پژوهشی
عنوان مقاله English
نویسندگان English
The durability of construction material plays a pivotal role in sustainable development. Therefore, appraising the material durability is of notable importance, especially for cement-based composites. This study centers on evaluating the durability of self-compacting mortar exposed to early-age freezing at -5°C, -10°C, and -15°C (in the first 24 hours after molding) and sulfuric acidic environments of pH=2. To this end, the compressive strength of 140 cubic samples was measured in pre- and post-freezing conditions and after 12 weeks of acid exposure. Further, the weekly weight variation of the samples was recorded. During the study, the role of Nano-Fe3O4 particles, as a proven strength enhancer, was examined. The results revealed that using 1.5% or more of NanoFe3O4 may impose unwanted effects on the compressive strength. Leading to agglomeration, this issue arises from the magnetic behavior of Fe3O4, which consequently affects the quantity and size of pores. In sulfuric acid-exposed samples, the chemical reaction of acid with free lime and C-S-H structure is the most significant damaging factor. Further, in those samples exposed to the acidic environment, the existence of magnetite nanoparticles leads to weight reduction and strength drop in specimens. The reason for this issue is increasing pores and micro-cracks in samples as a result of the magnetite magnetic field and, also, the chemical reaction of sulfuric acid with magnetite particles, which leads to elimination of their positive role as fillers.
کلیدواژهها English
