研究不同长度秸秆纤维(1～5mm、5～10mm、10～20mm)、粉煤灰和硅藻土协同作用对秸秆水泥基材料力学性能及抗冻性能的影响规律,通过SEM进行微观表征。正交设计确定水泥基复合材料的最佳配方为:粉煤灰取代率10%;硅藻土取代率4%;水胶比0.48,最佳活性掺合料组和空白组28d抗压强度分别为58MPa和46.3MPa,相比之下,活性掺合料组强度提高25.3%;随着三种长度秸秆纤维掺量的增加,抗压强度均逐渐下降,其中5～10mm的秸秆水泥基材料力学性能最佳,当纤维掺量为5%时冻融循环可达35次。

The effects of different lengths of straw fiber (1～5mm,5～10mm,10～20mm),fly ash and diatomite on the mechanical properties and frost resistance of straw cement-based materials were studied.Microscopic characterization was performed by SEM.The orthogonal design determined that the optimal proportions of fly ash,diatomaceous earth,and water-binder ratio in the cement-based composite materials were 10%,4%,and 0.48,respectively.The 28-day compressive strength of the best active admixture group and the blank group was 58MPa and 46.3MPa,by contrast,the strength increased by 25.3%.With the increase of the amount of straw fiber content,the compressive strength gradually decreased.Among them,the 5～10mm straw cement-based material had the best mechanical properties.When the fiber content was 5%,the freeze-thaw cycle can reach 35 times.