چگالي ويژه و ميزان جذب آب سنگ‌دانه هاي بازيافتي حاصل از نخاله هاي بتني (مطالعه‌ي موردي: منطقه‌ي پارس 2 كنگان)

Specific Gravity and Water Absorption of Recycled Concrete Aggregates (Case Study; Pars -2 Kangan Region)

در مطالعه‌ي حاضر به بررسي استفاده‌ي مجدد نخاله هاي ساختماني حاصل از فرآيند تخريب و ساخت و ساز منطقه‌ي پارس 2 كنگان پرداخته شده است. هدف از اين پژوهش، ارزيابي چگالي ويژه و ميزان جذب آب سنگ‌دانه هاي بازيافتي حاصل از نخاله‌هاي بتني منطقه‌ي مذكور جهت كاربرد به عنوان بخشي از سنگ‌دانه هاي مورد استفاده در لايه هاي روسازي است. نخاله هاي ذكرشده پس از خردشدن در سنگ‌شكن با محدوده‌ي 25-0 ميلي‌متر دانه بندي شده و سپس 4 طرح اختلاط مجزا با درصد سنگ‌دانه هاي بازيافتي 0، 10 ، 30، و 50 جهت بررسي عملكرد آنها در تركيب لايه هاي روسازي تهيه و مورد آزمايش قرار گرفته و نتايج نشان داده است كه سنگ‌دانه هاي بازيافتي نسبت به سنگ‌دانه هاي طبيعي، چگالي ويژه‌ي كمتر و ميل به جذب آب بيشتري دارند، كه اين امر به علت وجود ملات چسبيده به آن‌هاست.

Despite the fact that construction and demolition wastes (C and D wastes) compared to other types of waste has less risk to the environment and their management is relatively simple, but from an aesthetic point of view was not accepted by the general public and must be disposed properly. C & D wastes often due to the lack of proper management, are stacked or buried in the periphery of cities, roads and rivers are disposal, while most have the ability to be recycled and reused. On the other hand, due to different material properties in various regions, discover the proper loan resources for civil projects always including the challenges is facing the design engineers. This study investigates the reuse of C & D wastes such as concrete and cement blocks resulting from the construction and demolition processes of Pars 2 region, in pavement layers. Due to the scarcity and high value of land in the region, disposal options of this typical debris are not cost effective and should be recycled as part of the waste of construction process operations. On the other hand due to the lack of quarried rock mines in this region, excessive use of river materials, causes the loss of the normal cover from earth surface and ultimately results in soil erosion. Hence, the reuse of C & D wastes in the construction process would be economically and environmentally affordable. This debris after being crushed in a crushing machine, results grains with diameter ranging from 0 to 25 mm size four mixes with the percentage of recycled aggregates zero , 10 , 30 and 50 percent were prepared to evaluate the performance of the combined pavement layers. Results indicated that these aggregates have less specific weight and durability and show higher water absorption in comparison with the natural aggregates.