Digital holography is applied to measure the characteristics of transparent material. A digital hologram recording system to measure the surface of transparent material was established, and the digital holograms of transparent object were obtained in high quality. For postprocessing of hologram, the least-squares phase unwrapping algorithm was used in phase unwrapping, and the phase reconstruction image of transparent object was obtained. The information of material surfaces was measured and the characteristic was presented in 3D visualization. The validation experiment was conducted by NanoMap 500LS system; the results of validation experiment are well satisfied with the measurement by digital holography, which proved the feasibility of digital holographic technology as a good measurement tool for transparent material.

关键词：汽车；透明材料；数字全息技术

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Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement damage. The PPC was applied in three methods; (1) as a 1 inch thick inlay of the entire lane that was diamond ground to remove all rutting from studded tire wear, (2) as an inlay of just the wheel paths that were diamond ground, and (3) as a feathered overlay of the existing pavement which had no diamond grinding to remove rutting. The test sections will be monitored for a minimum of five years to determine the performance of the PPC with particular emphasis on its ability to resist studded tire wear.

关键词：聚酯聚合物混凝土(PPC)；路面损伤修复策略

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The post-fire axial compressive behavior of a set of self-stress lightweight aggregate concrete filled steel tubes (noted as SSLC-ST) after exposure to fire was studied.Effect of the fire temperatures of the specimens and some parameters on the axial compressive behavior of the specimens was especially discussed.The results show that the initial circumferential strain of surface of the steel tubes is much larger than the longitudinal strain of the steel tubes,and the specimens of SSLC-ST have higher post-fire axial compression bearing capacity and better plastic deformation.It was concluded that the local buckling and overall failure of the specimens take place in succession while the specimens are axially loaded,and there are a lot of slip lines with angle of 45° on surface of the steel tubes.

关键词：钢铁；钢管混凝土；自应力陶粒钢管；火灾后行为；轴向挤压

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The issue of sustainability in the built environment is increasingly important, particularly in the transportation sector.In this research, laboratory investigations of the use of steel slag as a portland cement concrete (PCC) aggregate were reviewed. Much of this research took place outside the United States.

关键词：钢铁；钢渣集料；硅盐酸水泥混凝土

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On the basis of the theoretical study and application of ordinary steel-encased concrete composite beam,this paper will focus on a new high-strength steel-encased concrete composite beam,and mainly studies high-performance steel Q420 and Q460,as well as high-strength concrete C60 and C80.Besides,an experimental study of 5 simply-supported beams is made,and the load-deflection curves of new SCCB are analyzed.The calculation formula of load which changes with depth of section and bending strength of the cross section is also analyzed.It is suggested that the calculated results announced should be identical with the experimental results.

关键词：钢铁；高强度外包钢混凝土复合梁；高性能；承载力

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A recent rise in asphalt binder prices has led state agencies and contractors to use higher quantities of Reclaimed Asphalt Pavement (RAP). Besides being economic, sustainable, and environmentally friendly, RAP can be replaced for a portion of aggregates in Hot Mix Asphalt (HMA) where quality aggregates are scarce. In this project, the effect of increasing RAP percentage and using fractionated RAP (FRAP) in HMA mixture on moisture resistance, rutting, and fatigue cracking were evaluated. Mixtures with five different RAP and FRAP contents (20, 30, and 40RAP, and 30and 40FRAP) were studied. The Hamburg Wheel Tracking Device (HWTD) Test (TEX-242-F), Kansas Standard Test Method KT-56 or modified Lottman Test, and Dynamic Modulus Test (AASHTO TP: 62-03) were used to predict moisture damage, rutting potential and fatigue cracking resistance of the mixes. HMA specimens were prepared based on Superpave HMA mix design criteria for 12.5 mm (1/2 inch) Nominal Maximum Aggregate Size (NMAS) and compacted using the Superpave gyratory compactor. Results of these tests showed that although mixture performance in the laboratory tests declined as the percentage of RAP increased in the mix, even mixtures with 40RAP passed the minimum requirements in commonly used tests.

关键词：修复计划；沥青；高速公路

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Highway agencies continuously strive to expedite pavement construction and repairs and to evaluate materials and methods to provide long-lasting pavements. As part of this effort, agencies have used precast concrete slabs for more than 10 years with successive improvements in processes and systems. The Virginia Department of Transportation recently used two precast systems along with conventional cast-in-place repairs on a section of jointed reinforced concrete pavement on I-66 near Washington, D.C. One precast system, precast concrete pavement (PCP), used doweled joints. The other precast system, prestressed precast concrete pavement (PPCP), used transversely prestressed slabs post-tensioned in the longitudinal direction. Both precast systems are performing satisfactorily after 1.5 years of traffic, and the contractor was satisfied with the constructability. In multiple locations, transverse expansion joints in PPCP were observed to be wider than the 12-in width specified; excessively wide joints often compromise joint sealant performance, and erosion from water flowing through such joints may result in eventual loss of support over time. There were a few cracks in the PPCP section, originating mainly from grouting holes, cracks in the block-out patches, cracks and loss of epoxy at lifting hook holes, and corner breaks. There were some mid-slab cracks in the PCP slabs immediately after opening to traffic, but they are still tight and stable after 1.5 years of traffic. Even though the precast slabs initially cost more than the cast-in-place repairs to construct, the ability to construct the pavement within a short period of lane closure per day and the probability of improved quality control of plant-cast concrete warrant their use. Since this was the first application in Virginia, certain issues occurred and most were overcome, such as matching of slabs and grout leakage. The project was successfully completed and further implementation is recommended.

关键词：路面；预制系统；混凝土；质量控制

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Traditional assembly line manufacturing is speculative, costly and environmentally unsustainable. It is speculative because it commits substantial resources—energy, materials, shipping, handling, stocking and displaying—without a guaranteed sale. It is costly because each of these resources—material, process, people and place—involves expense not encountered when a product is manufactured at the time of sale. It is environmentally unsustainable because, no matter how much recycling is done, not using the resources unless actually needed is always a better path. Three-dimensional printing is currently of great commercial interest as it can be employed to manufacture parts on-demand economically and without the significant cost & environmental downsides, i.e. inventory and waste, associated with traditional manufacturing processes. Herein, we describe the formulation of a novel water-based material which can be used in a traditional 3D printer extrusion process to create optically transparent glass-based objects. Such objects have a wide range of applications including, but not wholly limited to: security printing using color & coating effects, protective films and coatings, electronic codes readable by smartphones, tablets or touch screens. Additional all glass objects traditionally manufactured by the so called kiln glass method can be generated by this type of 3D printing making it interesting for the high end market of art objects.

关键词：胶体；挤压；3D打印

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Traditional assembly line manufacturing is speculative, costly and environmentally unsustainable. It is speculative because it commits substantial resources—energy, materials, shipping, handling, stocking and displaying—without a guaranteed sale. It is costly because each of these resources—material, process, people and place—involves expense not encountered when a product is manufactured at the time of sale. It is environmentally unsustainable because, no matter how much recycling is done, not using the resources unless actually needed is always a better path. As part of the RAGNAROK (Research on Advancing Glass & Nonorganic Applications to Recreate Objects & Kinetics) project in HP Labs, we identified glass as a promising candidate for additive manufacturing based on 3-D printing methods. Glass is a silica-based material. With 90% of the earth’s crust composed of silicate minerals, there will be no shortage of silica resources. Glass is easy to recycle and is environmentally friendly. Glass is inexpensive but looks precious, is pleasant to the touch and is so familiar that customers will not be disappointed by its fragility— under certain conditions. A major need, and concomitantly a major challenge, for 3D printed glass is transparency. We will discuss several methods how to achieve it.

关键词：3D打印；透明玻璃

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