摘要
Cementitious alkali activated aluminosilicates pastes were produced from recycled and locally obtainable materials in Iraq. The compositions were based on recycled bricks, water glass, commercial caustic soda flakes, and nano silica. The nano silica was prepared from the abundant local ＂Iraqi anber＂ rice husks and added to the prepared pastes in different weight percentages. Another set of pastes was prepared via adding 5w% of＂A1-Najaf＇ fly ash at the expense of the recycled bricks powders. The pastes were cured for 1-28 days under ambient conditions. The compressive strengths for the cured pastes were measured. In addition, the cured pastes were characterized via X-ray diffraction, FTIR, and optical microscopy. The addition of the nano silica and longer curing times improve the microstructure packing and thus increases the compressive strengths. The added fly ash impregnates the microstructure with extra gel phase and further improves the compressive strengths of the cured pastes.
