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Because they have a high application potential in the thermal management of insulation environments, high-quality hexagonal boron nitride (h-BN)-based multiphase ceramics have been highly desired. However, so far, their synthesis is still full of challenges. Here, a kind of boron nitride nanosheets (BNNSs)/glass (GS) composite ceramics was prepared by a pressureless sintering method at a lower temperature of 900 °C. Due to a tightly bonded interaction between BNNSs and GS, the formed BNNSs/GS ceramics exhibit excellent multifunction performance. They have an outstanding compressive strength in the range of 19 ∼ 64 MPa and Vickers hardness ranging from 50 to 179 HV. For the BNNSs/GS ceramics with BNNS's filling fraction of 90 wt%, their maximum side-surface TC values are 12.01 ± 0.18 W m−1 K−1 at 25 °C and 13.64 ± 0.37 W m−1 K−1 at 300 °C, respectively. In the ultra-high frequency range of 26.5 ∼ 40 GHz, the dielectric constant values of the BNNSs/GS ceramics are primarily between 2 and 3, and the corresponding loss tangent values are < 0.3. In addition, based on the remarkable integrity of their structure, these BNNSs/GS ceramics exhibit outstanding thermal-shock stability and prominent thermal management capacity during lots of heating/cooling-testing cycles. Therefore, we believe this kind of BNNSs/GS ceramic system will have great application potential in the new-generation thermal management and/or insulation packaging fields. [ABSTRACT FROM AUTHOR]

Wicking geotextile has been increasingly utilized in field projects to mitigate water-related roadway problems. The previous studies showed that the wicking geotextile could provide mechanical stabilization, serve as capillary barrier, and enhance lateral drainage. The wicking geotextile differentiates itself from non-wicking geotextiles by providing capillary or wicking drainage in unsaturated conditions, whereas non-wicking geotextiles only provide gravitational drainage under saturated or near-saturated conditions. Although the previous studies have demonstrated the benefits of soil water content reduction by the wicking drainage, it is not well understood how the wicking geotextile stabilization improves overall performance of aggregate bases over subgrade under traffic or cyclic loading. This paper presents an experimental study where large-scale cyclic plate loading tests were conducted under different conditions: (1) non-stabilized base, (2) non-wicking geotextile-stabilized base, and (3) wicking geotextile-stabilized base, over soft and moderate subgrades. Rainfall simulation was carried out for each test section. After each rainfall simulation, a drainage period was designed to allow water to drain from the section. The amounts of water applied and exiting from the test section were recorded and are compared. Cyclic loading was applied after each drainage period. The test results show that the combined hydraulic and mechanical stabilization effect by the wicking geotextile reduced the permanent deformation of the aggregate base over the subgrade as compared with the non-stabilized and non-wicking geotextile-stabilized sections. ⁃ This paper presents an experimental study on the improved performance of wicking geotextile-stabilized bases over different subgrades over non-wicking geotextile-stabilized bases and control bases after simulated rainfalls. ⁃ Large box tests clearly demonstrate the benefits of the wicking geotextile to remove more water from the base courses by capillary drainage as compared with other test sections. ⁃ Large box tests also show that the wicking geotextile significantly reduced permanent deformations of the base courses under cyclic loading as compared with other test sections. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the distance effect on water reduction by the wicking geotextile in a base course experimentally using three sets of soil column tests. In each set of tests, two soil columns were constructed by compacting well-graded aggregate over a non-wicking woven geotextile and a wicking geotextile. A portion of the geotextile specimen was extended outside of the soil column for evaporation. The changes of the water contents in the soil column were monitored by volumetric water content sensors installed at various depths. The experimental results indicate the capillary drainage by the wicking geotextile effectively reduced water content within the soil column up to a distance from the wicking geotextile (i.e., approximately 200 mm for this specific aggregate with 10% fines). The test results also show that the wicking geotextile could reduce more water content of the aggregate below its optimum water content at a faster rate than the non-wicking geotextile. [ABSTRACT FROM AUTHOR]