Yang Heng, Qian Zengzhen, Yue Bing, Xie Zilu
School of Engineering and Technology, China University of Geosciences, Beijing 100083, China.
Key Laboratory on Deep Geo-Drilling Technology, Ministry of Natural Resources, Beijing 100083, China.
Materials (Basel). 2024 Aug 8;17(16):3946. doi: 10.3390/ma17163946.
Aeolian sand is distributed worldwide, exhibiting poor grading, low cohesion, and loose structure. Infrastructure construction in desert areas sometimes requires stabilization of the sand, with cement as the primary curing agent. This study first employed orthogonal experiments to evaluate critical factors, e.g., curing time, cement dosage, and water dosage, affecting the unconfined compressive strength (UCS) of the aeolian sand stabilized with cement (ASC). Each of the aforementioned factors were set at five levels, namely curing time (7, 14, 28, 60, and 90 days), cement dosage (3%, 5%, 7%, 9%, and 11%), and water dosage (3%, 6%, 9%, 12%, and 15%), respectively. The water and cement dosages were percentages of the mass of the natural aeolian sand. The results indicated that the sensitivity of the influencing factors on the UCS of ASC was cement dosage, curing time, and water dosage in descending order. The UCS of ASC positively correlated with curing time and cement dosage, while it first increased and then decreased with the water dosage increase. The optimal conditions were 90 days' curing time, 11% cement dosage, and 9% water dosage. The microscopic analyses of ASC using optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) revealed that hydration products enhanced strength by bonding loose particles and filling pores, thereby improving compaction. The quantity and compactness of hydration products in the aeolian-cement reaction system increased with the increases in cement dosage and curing time, and low water dosage inhibited the hydration reaction. This study can provide insights into the stabilization mechanism of aeolian sand, aiding infrastructure development in desert regions.
风积沙分布于世界各地，具有级配差、内聚力低和结构松散的特点。沙漠地区的基础设施建设有时需要对沙子进行加固，以水泥作为主要固化剂。本研究首先采用正交试验来评估影响水泥稳定风积沙（ASC）无侧限抗压强度（UCS）的关键因素，如养护时间、水泥用量和水用量。上述每个因素分别设置为五个水平，即养护时间（7、14、28、60和90天）、水泥用量（3%、5%、7%、9%和11%）和水用量（3%、6%、9%、12%和15%）。水和水泥用量均为天然风积沙质量的百分比。结果表明，影响因素对ASC的UCS的敏感性依次为水泥用量、养护时间和水用量。ASC的UCS与养护时间和水泥用量呈正相关，而随着水用量的增加，UCS先增加后降低。最佳条件为养护时间90天、水泥用量11%和水用量9%。使用光学显微镜、扫描电子显微镜（SEM）和X射线衍射（XRD）对ASC进行微观分析表明，水化产物通过粘结松散颗粒和填充孔隙来增强强度，从而提高压实度。风积沙 - 水泥反应体系中水化产物的数量和密实度随着水泥用量和养护时间的增加而增加，低水用量会抑制水化反应。本研究可为风积沙的加固机理提供见解，有助于沙漠地区的基础设施建设。
