Preparation and properties of gradient structure concrete member
Based on the dense packing powder theory, the refining and self-healing principles, and hydrophobic treatment, the special surface-layer materials and design are proposed in gradient structure concrete (GSC) member. According to service behavior, the GSC member is divided into serial structure and parallel structure. And it is fabricated corresponding to structural parameters by stacked press process, or pulled clapboard method, or suspended nets method. Use of small and full scale specimens for testing, the results are shown that: 1) the surface-layer strength of the GSC component improved by 30%, compared to that of a conventional single-layer component; 2) the width of the crack ranges from 0 to 0.1mm in the GSC component, whereas a conventional single-layer component are distributed with visible cracks(0.2–0.5mm);3) The permeating depth and chloride diffusion coefficient of the GSC component is respectively 0mm and 6.3×10–13 m2/s, whereas a conventional single-layer component is 15mm and 12.8×10–13 m2/s.
Design and Research on Gradient Structure Concrete Based on Volumetric Stabilization
This research studied the gradient-structural design method of concrete due to underground concrete’s degradation characteristics. The interlaminar deformation consistency was controlled to optimize the material, structure, and performance by means of interface mechanics. The accelerated test falls into 2 groups: one made to evaluate the swelling deformation value of the sample with a single-side exposed simulation environment and the other to characterize the environmental damage by the electric flux change. The gradient structure concrete (GSC) system is easily found to be much more stable based on the following evidence: 1) the swelling value of the GSC system declined by approximately 60-74% in 44 weeks; 2) the corrosion resistance coefficient K increased and the K210 value was still larger than 1, compared to that of a conventional single-layer structure system; and 3) the change in electric flux of the GSC system only increased from 149 to 252 coulomb (1 coulomb = 1A × sec.), whereas conventional single-layer structure systems increased noticeably from 1267 to 2728 coulomb.
Monitoring and Optimization of Internal Grinding Process
Summary The grinding process is influenced by many factors such as grinding wheel characteristics, dressing conditions and, course, grinding conditions. Therefore, it is difficult to perform the grinding operation in an optimum state. In this study, in-process monitoring methods using power and acoustics emission sensors are proposed to detect malfunctions in the internal grinding process. In addition, a new internal grinding cycle featuring rapid indeed is proposed to minimize the grinding cycle time.