外掺料对植被混凝土高羊茅根系生长及抗剪强度的作用

为揭示外掺料对植被混凝土根系生长和固土护坡的作用，以高羊茅（Festuca arundinacea）为研究材料，分别添加不同含量的椰纤维与粉煤灰构建植被混凝土，测定高羊茅地下部根系的生长特征及根土复合体的抗剪强度。结果表明，椰纤维掺量和粉煤灰掺量对高羊茅根系生长有显著影响。根系总根长、根系表面积、根平均直径及地下生物量均随椰纤维与粉煤灰掺量的增加呈先增后减的变化趋势，在椰纤维掺量为0.3%、粉煤灰掺量为2%时达到最大值，分别比未添加椰纤维的处理增加了31.39%、30.20%、30.57%、12.80%，分别比未添加粉煤灰的处理增加了42.17%、22.85%、16.48%、29.22%。椰纤维掺量和粉煤灰掺量对植被混凝土基材的抗剪强度也有显著影响，基材的抗剪强度均随着外掺量增加呈先增加后减少的变化，在椰纤维和粉煤灰掺量分别为0.3%和2%时达到最大值。综合评估显示，高羊茅根系在外掺椰纤维0.3%和粉煤灰2%的改良植被混凝土生长最好，植被混凝土的抗剪强度最高。

Effect of external admixtures on the growth and shear strength of Festuca arundinacea roots in vegetated concrete

In order to reveal the effects of external admixtures on the root growth and soil consolidation and slope protection of vegetation concrete, Festuca arundinacea was used as the research material, and different contents of coconut fiber and fly ash were added to construct vegetation concrete to measure the growth characteristics of Festuca arundinacea underground root system and the shear strength of root-soil complex. The results showed that the content of coconut fiber and fly ash had significant effects on the growth of Festuca arundinacea root system. The total root length, root surface area, root average diameter and underground biomass all increased first and then decreased with the increase of the content of coconut fiber and fly ash. When the content of coconut fiber was 0.3% and the content of fly ash was 2%, they reached the maximum value, which increased by 31.39%, 30.20%, 30.57% and 12.80%, respectively, compared with the treatment without coconut fiber. Compared with the treatment without fly ash, they increased by 42.17%, 22.85%, 16.48% and 29.22%, respectively. The coconut fiber content and fly ash content also had significant effects on the shear strength of the vegetated concrete substrate. The shear strength of the substrate increased first and then decreased with the increase of the addition content, and reached the maximum value when the content of coconut fiber and fly ash was 0.3% and 2%, respectively. The comprehensive evaluation showed that the improved vegetation concrete with Festuca arundinacea root system mixed with 0.3% of coconut fiber and 2% of fly ash had the best growth, and the shear strength of vegetation concrete was the highest.