生土建筑基体-面层界面抗剪性能的试验研究

Experiment Study on Shear Resistance of Earthen Building Matrix-Surface Layer Interface

采用天然生土(NS)、水性聚氨酯改性生土(WPS)、天然水硬性石灰改性生土(NHLS)、人造水硬性石灰改性生土(AHLS)制作了10组30个生土面层与基体黏结的试件。通过0、100、200 kPa垂直荷载作用下界面直剪试验,得到不同基体-面层的剪应力-位移关系曲线和抗剪强度。结果表明,界面主要发生黏结破坏。垂直荷载施加到100 kPa,抗剪强度提高20%~30%;施加至200 kPa,抗剪强度最高,部分界面出现啃断与黏结组合破坏。总体而言,WPS面层的抗剪强度和刚度均最大,但易产生基层剥离。AHLS和NHLS面层的抗剪性能较接近,均优于NS面层。

Ten sets of 30 specimens were prepared using natural raw soil(NS),waterborne polyurethane modified raw soil(WPS),natural hydraulic lime modified raw soil(NHLS),and artificial hydraulic lime modified raw soil(AHLS)to examine their bonding with substrates.Through direct shear tests under vertical loads of 0,100 kPa and 200 kPa,the shear stress-displacement curves and shear strengths for different sub⁃strate-coating interfaces were obtained.The results indicate that the interface primarily experiences adhesive failure.When a vertical load of 100 kPa is applied,the shear strength is increased by 20-30%.At 200 kPa,the shear strength peaks,with some interfaces showing a combination of bite-off and adhesive failure.Overall,the WPS coating exhibits the highest shear strength and stiffness but is prone to substrate peeling.The shear performance of the AHLS and NHLS coatings is similar and superior to that of the NS coating.