掺合料对再生混凝土三孔砖力学及抗冻性能的影响

Admixture influenced on mechanics and frost resistance of recycled concrete bricks of three holes

利用废弃黏土砖制备再生混凝土三孔砖,通过改变粉煤灰、矿粉的掺量,研究单掺、复掺掺合料裹骨料对再生混凝土三孔砖的抗压强度和冻融循环后强度损失及质量损失的影响。结果表明:采用粉煤灰、矿粉裹骨料搅拌工艺制备再生混凝土三孔砖,改善了混凝土三孔砖的力学及抗冻性能,使混凝土三孔砖达到国家承重墙体材料的标准要求。复掺矿粉、粉煤灰的改性效果优于单掺掺合料改性效果,当矿粉掺量为20%,粉煤灰掺量10%时,改性效果最优,混凝土28 d抗压强度达到最大值47.2 MPa,抗冻性最好,其抗冻质量损失最低为0.3%,强度损失最低为8%。

By using discarded clay brick,we prepare recycled concrete bricks of three holes.By changing the mixed quantity of fly ash and mineral powder,we research the only mixed and complex mixture with aggregate influenced on strength loss and quality loss after freeze-thaw cycle strength loss of recycled concrete bricks of three holes.The results show that,by using fly ash and mineral powder wrapping aggregate,we prepare recycled concrete bricks of three holes.which improve mechanics and frost resistance of concrete bricks of three holes,and make concrete bricks of three holes reach countries bearing wallboard material standards.The modification effect of complex mixture with mineral powder is better than only mixed aggregate＇s modification effect.When mixing content of mineral powder is 20%and mixing content of fly ash is 10%,modification effect is optimal.28 days compressive strength of concrete bricks of three holes reaches maximum 47.2 MPa and freezing resistance is best.The minimum of anti-freeze quality loss is 0.3%and the minimum of strength is 8%.