ارزیابی دوام روسازی بتن قلیایی حاوی سرباره و دوده سیلیسی

در سال های اخیر با استفاده بیش از حد سیمان باعث تولید بی رویه گازهای گلخانه‌ای شده که یکی از عواقب آن گرمایش زمین بوده است. این اثرات مخرب باعث شد تا توجه بیشتر به استفاده بهینه از منابع، مواد پوزولانی و ضایعات گردد، در همین راستا استفاده از سرباره کوره آهن گدازی و دوده سیلیسی در صنایع مختلف از ‌جمله روسازی راه به ‌عنوان یک راه‌حل مطرح بوده است. استفاده از بتن سرباره قلیا فعال(ژئوپلیمری) با جایگزینی دوده سیلیسی بجای سیلیس موجود در سیلیکات سدیم و جایگزینی بجای سرباره علاوه بر مصرف مصالح ضایعاتی، این امکان را فراهم می‌کند تا بتوان مقاومت و دوام روکش‌های بتنی افزایش یابد. با جایگزینی دوده سیلیسی بجای سرباره مقاومت و دوام بتن کاهش می یابد، اما با جایگزین دوده سیلیسی به جای سیلیس موجود در سیلیکات سدیم مقاومت و دوام افزایش می یابد. با جایگزینی 30% دوده سیلیسی بجای سیلیس موجود در سیلیکات سدیم، افزایش مقاومت فشاری به مقدار %43.8، افزایش مقاومت خمشی نیز به مقدار %58.9، افزایش دوام در برابر چرخه یخ زدن و آب شدن به میزان %78.2، افزایش دوام در برابر سولفات سدیم به میزان %57.1، افزایش دوام در برابر سولفات منیزیم به میزان %54.1 و کاهش ضخامت دال روسازی به میزان %20.8 نسبت به بتن سیمانی را بدنبال داشته است.

Durability of alkali-activated slag/silica fume(AASS) concrete pavement

Roads are one of the most important and valuable assets of countries, and remarkable amounts are spent annually to repair and restructure them. The pavements are divided into two main groups of flexible pavements (asphalt pavements) and rigid pavements (concrete pavements). In Iran, mainly used asphalt pavements, which were formerly about 90 years old. Therefore, there are many reasons why the most important of them, according to most experts, is the use of the country from abundant oil resources and low initial costs in the construction of this type of pavement. In recent years, with the entry of bitumen as one of the main components of the asphalt composition of the commodity exchange and consequently the increase in the cost of manufacturing and manufacturing asphalt, as well as the development of cement production plants in the country and the creation of carbon dioxide (CO2), a suitable platform for the development of geopolymeric concrete pavements in competition with asphalt pavements and concrete cement has been provided. In addition to abbility of bearing and reducing the pressure caused by the vehicle wheels, the pavement layers should be durable against atmospheric and physical factors, including the natural elements of the freezethaw cycles, acids and sulfates. Th pavement must be able to withstand the durability and durability of the pavement and maintain its service over the lifetime specified.These destructive effects led to more attention to the optimal use of resources, pozzolanic materials, and waste. In this regard, the use of ground granulated blast furnace slag and Silica fume in various industries such as road construction and building have been considered as a solution, however, practical, accurate and effective steps have not been taken yet. This research tried to present the materials and experiments carried out and to summarize them in order to eliminate the obstacles and obtain the necessary results for the use of alkaline concrete (geopolymeric) in the manufacture of durable concrete veneers in the pavement.The use of alkaliactivated slag concrete with the replacement of Silica fume instead of silica in sodium silicate, in addition to the use of waste materials, enables the strength and durability of concrete pavement to be increased under freezing and thawing cycles, acid attacks and being sulfate.In this study, alkaliactivated slag concrete with different percentages of Silica fume was studied using The experiments of compressive and bending strength, durability under freezethaw cycles, sulfuric acid, and magnesium sulfate attacks. The results showed that the replacement of 30% silica fume instead of silica in sodium silicate, increasing the compressive strength to 43.8%, increasing the bending strength by 58.9%, increased the durability under freezing and thawing cycles by 78.2%, increasing durability against sodium sulfate to The rate of 57.1%, increase the durability against magnesium sulfate by 54.1%, and the reduction of pavement slab thickness by 20.8% compared with concrete cement.