ارزيابي آزمايشگاهي عملكرد ستون سنگي شناور ساخته شده با مصالح بازيافتي

EXPERIMENTAL STUDY OF THE PERFORMANCE OF FLOATING STONECOLUMNS FILLED WITH RECYCLED MATERIALS

در اين تحقيق با استفاده از آزمايش هاي بارگذاري محوري كوچك مقياس، و جايگزين كردن مصالح بازيافتي با مصالح طبيعي در ساخت ستون سنگي، رفتار ستون سنگي شناور با مصالح بازيافتي براي بهسازي بستر رسي مورد ارزيابي قرار گرفته است. بدين منظور ستون سنگي منفرد از سه گروه مصالح مختلف شامل: خرده آجر و خرده بتن و سنگدانه ي شني ساخته شد. به منظور ارزيابي كيفيت مصالح بازيافتي، از آزمون هاي شاخص مصالح مثل ارزش خردشدگي سنگدانه و ارزش ضربه يي سنگدانه استفاده شد. نتايج آزمون هاي شاخص مصالح بازيافتي بيانگر عملكرد ضعيف اين مصالح در مقايسه با سنگ دانه هاي طبيعي بوده اند. عليرغم اين موضوع، ظرفيت باربري بستر رس مسلح به ستون شناور پرشده با خرده آجر يا خرده بتن تقريبا 5 برابر ظرفيت باربري بستر رسي بدون ستون سنگي است. همچنين نتايج مدلسازي فيزيكي نشانگر آن است كه ستون هاي سنگي شناور ساخته شده از يك نوع سنگدانه، عملكرد به مراتب بهتري از ستون ساخته شده از تركيب چند نوع مصالح بازيافتي با يكديگر يا تركيب سنگدانه بازيافتي با سنگ دانه طبيعي دارند.

In this study, the behavior of the floating stone column in clay bed was evaluated using a scale small-axial loading tests and the replacement of recycled materials with natural materials in the construction of the stone column. Since the construction of stone columns requires huge amounts of natural aggregates and limits on the supply of aggregate environmental aspects such as transportation-induced pollution, and the management of construction and demolition wastes through waste reuse and recycling would bring the use of recycled materials in stone columns to consider. According to this study's findings, the use of a combination of recycled aggregates might lead to the achievement of the goals; however, future research studies are needed to investigate other available and similar materials. For this purpose, the individual stone columns were made of three different materials such as the crushed brick, the crushed concrete, and the gravel aggregate. The material index tests, such as aggregate crushing value and aggregate impact value, were used to assess the quality of recycled materials. Due to the fact that the surcharge pressure is greater in the depth of the soil, the passive pressure of the soil is mobilized and creates more confinement. Therefore, the stiffness of materials in the floating stone column alone is not an effective factor in increasing the bearing capacity, and the bulge of the column at lower depths plays an important role in the bearing capacity of the columns. The results show that the recycled materials provide poor performance compared to natural aggregates. However, the bearing capacity of the clay bed reinforced using the floating column with crushed materials is approximately 5 times the capacity of soft bed without stone columns. Moreover, the results of the loading test show that the made floating stone columns provide suitable performance compared with the made columns using the combination of several types of recycled materials.