改性小麦秸秆/水泥复合材料的强度

Strength of Modified Wheat Straw/Cement Composites

为了加强小麦秸秆/水泥复合材料的性能,采用NaOH溶液对小麦秸秆进行改性,研究NaOH溶液浓度、改性时间对水泥砂浆强度的影响。结果表明,质量分数为4%的NaOH溶液改性处理24h时,秸秆质量损失率较大,可以减缓其对水泥的缓凝作用。此改性处理秸秆与水泥拌合的胶砂试样3d、28d抗折强度和抗压强度都大幅提高,与未改性秸秆胶砂强度相比,3d的抗压、抗折强度分别提高了3.12倍和4.16倍,28d的抗压、抗折强度分别提高2.21倍和3.58倍。电镜分析表明改性后的小麦秸秆与水泥胶体结合情况较好。

In order to strengthen properties of wheat Straw/Cement composite,the wheat straw was immersed in a NaOH solution and how concentration and modification time influence the strength of cement mortar was studied.The results show that the quality loss rate is relatively large when the mass fraction of NaOH solution is 4% and the modification time is 24 h.That can slow down the effect of the extract on the cement.The modified straw and cement mixing mortar specimen strength is significantly improved.Compared with unmodified straw mortar,the 3dcompressive strength and flexural strength are increased by 3.12 times and 4.16times;the 28 dcompressive strength and flexural strength are increased by 2.21 times and 3.58 times.SEM results indicat that the combination of modified straw and cement paste is relatively close.