ارزیابی تاثیر ژل میکروسیلیس، الیاف پلیمری، خاکستر بادی و تراشه آسفالت بر عملکرد و دوام بلوک کفپوش بتنی

در این مقاله یکی از راهکارهای کاهش گازهای گلخانه ای در روسازی های بتنی بلوکی، یعنی استفاده از مواد بازیافتی و الیاف پلیمری بررسی شده است. به همین منظور بلوکهای بتنی کفپوش حاوی ژل میکروسیلیس، خاکستر بادی، الیاف پلیمری و همچنین تراشه آسفالت ساخته شد و از نظر مقاومت فشاری، خمشی، دوام، مقاومت لغزشی به روش آونگ انگلیسی و مقاومت سایشی به روش چرخ غلتان مورد آزمایش قرار گرفتند. نتایج نشان داد که ژل میکروسیلیس بیشترین تاثیر را در بهبود مقاومت فشاری دارد. نتیجه آزمایش مقاومت خمشی آن بود که ژل میکروسیلیس قادر است مقاومت خمشی را نزدیک به 20% افزایش دهد.

evaluation of the effect of micro-silica gel, polymer fibers, fly ash and rap on the performance and durability of concrete pavers

in this article, one of the solutions to reduce greenhouse gases in concrete block pavements, i.e. the use of recycled materials and polymer fibers have been investigated. for this purpose, several concrete blocks, which are used in the upper part of the concrete block pavement system, were made by adding micro-silica gel, fly ash, macro and micro polymer fibers, as well as reclaimed asphalt pavement (rap) and were tested in terms of compressive strength, bending resistance, durability against periods of freeze and thaw, skid resistance by the british pendulum method and wear resistance by wide wheel abrasion method. results of the tests showed that micro-silica gel improves the compressive strength of the samples by 2 times and the bending strength by 20%. although polymeric fibers did not affect improving the compressive strength of the samples, but they could improve the modulus of rupture by about 5% because they prevent the expansion of tensile cracks. meanwhile, the other two materials, i.e. fly ash and rap, were not able to significantly increase the flexural strength. evaluation of the results of durability test showed that presence of 0.3% macro polymeric twisted fibers preserves the compressive strength of the samples before and after 50 cycles of freezing and thawing more than other additives. overall, comparison of the ratio of compressive strength of the samples after freezing and thawing to the strength of the samples before the test showed that using high percentages of micro-silica gel, fly ash and twisted macro polymer fibers increased durability of the control samples on the average by about 30%. results of the skidding resistance test also showed that macro twisted polymer fibers increase the skidding resistance of the control samples by about 50%. the abrasion resistance test with the wide wheel abrasion method also showed that micro-silica gel and rap play a more effective role in keeping the surface of the sample blocks unified, i.e. nearly 10% improvement, compared to other materials.