Utilizing industrial solid waste as supplementary cementitious materials (SCMs) in the production of pre-stressed high-strength concrete (PHC) pipe piles can reduce the consumption of cement, thereby promoting the sustainable development of the pipe pile industry. This study focused on optimizing the use of composite SCMs including ground quartz sand (GQS) and steel slag powder (SSP) to enhance the mechanical properties and durability of PHC pipe pile concrete. The effects of GQS and SSP on the reaction products, microstructure, pore structure, mechanical properties and durability of PHC pipe pile concrete were investigated. Experimental results showed that due to the filling effect and pozzolanic effect of GQS and SSP, composite SCMs not only improves the microstructure of the interfacial transition zone between paste and aggregates in PHC pipe pile concrete, but also reduces the porosity of concrete and improves its pore structure, thereby enhancing the compressive strength and durability of concrete. When the GQS content is 20 % and the SSP content is 10 %, compared to the control group with 100 % cement, the concrete's porosity decreased by 19.3 %, the chloride ion diffusion coefficient decreased by 47.1 %, and the compressive strength increased by 3.4 %. The findings of this study provide a scientific basis for the resource utilization of steel slag and offer theoretical support for the low-carbon and sustainable development of PHC pipe pile industry.

Studies on finger kinematics, especially the range of motion (RoM) measurements, are essential to understand the use of finger joints and the pathology of related disease. Limited literatures compared the active RoM (A-RoM) of finger joints with either their functional RoM (F-RoM) or passive RoM (p-RoM) using different measuring protocols and tools. This study aims to provide an overall comparison including all three types of RoMs. We measured A-RoM, F-RoM, and P-RoM, using a dynamic measurement system. Our goal is to investigate the relationships among the three RoMs by comparing their extreme rotation angles. The results suggested that P-RoM was the largest motion range, and F-RoM can exceed their A-RoM. The F-RoM of distal-interphalangeal joints may rotated 8–20° more than their A-RoM, mainly during precise and power manipulations. Besides to A-RoM, knowledge of F-RoM and P-RoM are also important for a comprehensive understanding for clinical practice, and thus, to support the optimization and evaluation of treatment devices for finger joint, such as implant replacement.