混凝土再生粉复合锰渣的胶凝性试验研究

原材料各组分对胶凝材料性能的影响较大,为此,探讨混凝土再生粉、锰渣、Na2SO4的掺量及水灰比对砂浆力学性能的影响,并采用吸水动力学法测定砂浆的孔结构参数(孔均匀系数、平均孔径、干表观密度),同时测定高温后砂浆的力学性能。结果表明:砂浆中掺入适量的Na2SO4、混凝土再生粉、锰渣或降低水灰比,均有利于提高砂浆的抗折强度,在早期较为显著,对后期的影响较小;适量的锰渣掺量有利于提高砂浆的抗压强度和耐高温性能; Na2SO4、混凝土再生粉、锰渣和水灰比都能在一定程度上改变砂浆的孔径分布,细化孔结构。因此,适量混凝土再生粉、锰渣、Na2SO4的掺入或降低水灰比,有利于提高砂浆的抗折/抗压强度和耐高温性能,细化砂浆孔结构。

Experimental study on gelling properties of recycled concrete powder composite manganese slag

The components and test conditions has great effect on the mechanical properties of mortar. Therefore, the content of concrete reclaimed powder, manganese slag, Na₂SO₄ and the ratio of water to cement were discussed. The pore structure parameters (pore homogeneity, average pore diameter and dry apparent density) of the mortar were determined by the water absorption kinetics method. The mechanical properties of the mortar after high temperature were also measured. The results show that adding mortar with proper amount of Na₂SO₄, recycled powder of concrete, manganese slag or reducing the ratio of water to cement can improve the flexural strength of mortar, and the effect was more significant in the early stage and then decreased. Appropriate amount of manganese slag content is conducive to improving the mortar compressive strength and high temperature performance. Na₂SO₄, concrete reclaimed powder, manganese slag and water-cement ratio all can change the pore size distribution of mortar to a certain extent and refine the pore structure. Therefore, the proper amount of recycled concrete powder, manganese slag, Na₂SO₄, incorporation or reduce the water-cement ratio is conducive to improve the mortar flexural/compressive strength and high temperature performance, and refine the pore structure of mortar.