بررسي آزمايشگاهي رفتار ديوارهاي مصالح بنايي از بلوك‌هايAAC تسليح‌شده با ميلگرد و الياف بسپاري GFRP

Experimental Evaluation of AAC Blocks Walls Retrofitted by Bars and GFRP

در اين پژوهش رفتار ديوارهاي تقويت‌شده از بلوك‌هاي بتن سبك اتوكلاوشده (AAC) با استفاده از آزمايش قطري مورد بررسي قرار گرفته است. نتايج بر روي 6 نمونه‌ي مقاومت برشي ملات ويژه، بيان‌گر بالاتربودن مقاومت برشي ملات در مقايسه با رده‌ي AAC مورد استفاده بوده است و در آزمايش بارگذاري قطري، 9 نمونه با ابعاد 250×1200×1200 ميلي‌متر كه شامل 3 نمونه‌ي ديوار شاهد و 3 نمونه‌ي تقويت‌شده با الياف بسپاري و مقاوم‌سازي‌شده‌ به صورت ضرب‌دري و با عرض‌هاي مختلف 100 و 200 ميلي‌متر بوده‌اند، موجب افزايش جذب انرژي به ترتيب 9/12 و 21 برابر شده‌اند؛ و 3 نمونه‌ي ديگر نيز ديوارهاي تسليح‌شده با ميلگرد بوده‌اند كه مقاومت كشش قطري آن‌ها 32? و مقدار جذب انرژي‌شان 2/28 برابر افزايش يافته است.

In this paper, the experimental behavior of an autoclaved aerated concrete (AAC) block, and the shear strength of the mortar used for construction of an AAC wall was given. Six specimens with micro silica mortar, suitable to the class of compressive behavior of AAC blocks, were tested. 9 specimens of an AAC wall, with dimension of 1200*1200*250, based on ASTM E519, were constructed. The diagonal testing program was used for the specimens. Three specimens were used as control. Three specimens were retrofitted by a diagonal GFRP plate; 100 and 200 mm wide. For the last three specimens, a reinforcing horizontal rebar (3mm diameter) and vertical (10mm diameter), recommended by the Iranian seismic, code was used. For this purpose, 2 holes were made, with 600 mm space and 60 mm diameter, for a 10mm diameter vertical rebar. After montage of one rebar in a hole, grout was used to fill the other parts of the hole. Reinforced AAC walls have higher resistance in diagonal tension tests. Diagonal strength increased by 32 percent, and the crack width achieved more than 22mm without any collapse of the reinforced walls, but, control specimens have brittle failure. Three specimens were retrofit with 100 and 200 mm FRP width in a diagonal direction, which increased the energy absorption 12.9 and 21 times. The mortar in the shear strength tests has more resistance than the shear strength of AAC walls with a compressive strength 3.2 MPa block. The wall behavior in this strength class of AAC showed that the failure modes consisted of: 1-diagonal tension failure mode and 2- crashing is on the toe.