Tiwari Nitin, Satyam Neelima, Singh Kundan
Discipline of Civil Engineering, Indian Institute of Technology Indore, Indore, India.
Sci Rep. 2020 May 6;10(1):7624. doi: 10.1038/s41598-020-64658-1.
This study presents the micro-physical investigation of polypropylene (PP) fiber-reinforced, and silica fume (SF) stabilized expansive soil (BC) subgrade. The coupling effect of soil, PP fiber, and SF has been evaluated under the freezing-thawing (F-T) cycle to assess the durability of treated BC Soil. The curing method and duration staggeringly influence the strength of SF treated BC soil; therefore, three different curing method, i.e., moisture-controlled curing (MC), gunny bag curing (GC), and water submerged curing (SC) to a period of 7, 14, and 28 days were considered. The BC soil has been reinforced with 0.25%, 0.50%, and 1.00% PP fiber and stabilized with 2%, 4%, 6% and 8% SF. The physical, chemical, and microstructural properties were determined before and after 2,4,6,8,10 F-T cycles. With the increase in SF content, the unconfined compressive strength of the expansive soil has been increased due to the formation of Calcium Silicate Hydrate (C-S-H) gel. The chemically inert, hydrophobic, non-corrosive nature, and higher tensile strength of PP fiber, it has a higher potential to reinforce the BC soil for durability under tensile failure. This research confirms the possibility of incorporating SF and PP Fiber in road work applications, with significant environmental benefits.
本研究对聚丙烯（PP）纤维增强、硅灰（SF）稳定的膨胀土（BC）路基进行了微观物理研究。在冻融（F-T）循环条件下评估了土壤、PP纤维和SF的耦合效应，以评估处理后BC土的耐久性。养护方法和养护时间对SF处理的BC土强度有显著影响；因此，考虑了三种不同的养护方法，即湿度控制养护（MC）、麻袋养护（GC）和水浸养护（SC），养护时间分别为7天、14天和28天。BC土分别用0.25%、0.50%和1.00%的PP纤维增强，并用2%、4%、6%和8%的SF稳定。在2、4、6、8、10次冻融循环前后测定了其物理、化学和微观结构性质。随着SF含量的增加，由于硅酸钙水合物（C-S-H）凝胶的形成，膨胀土的无侧限抗压强度有所提高。PP纤维具有化学惰性、疏水性、无腐蚀性以及较高的拉伸强度，在拉伸破坏情况下，它具有增强BC土耐久性的巨大潜力。本研究证实了在道路工程应用中掺入SF和PP纤维的可能性，并具有显著的环境效益。
