The concrete-filled steel tube structure possesses the advantages stemming from both steel and concrete. When the structure receives pressure, the concrete in the steel tube bears the stresses from three directions owing to the restriction of the steel tube.The combination of both materials can help conquer their respective weakness and bring their strong points into full play.play.Therefore the concrete-filled steel tube structure has a bright future. Whether a structure system has a bright future largely depends on the economic benefit of the system. This paper presents an economic analysis on concrete-filled steel tube structure by way of comparing the reinforced concrete structure.

Marine composites are materials used in the construction of off-shore structures and boat components to increase performance, decrease fuel consumption, and significantly reduce carbon dioxide emissions. They are often used as alternatives to traditional materials such as aluminum and steel. Composites such as glass fiber-reinforced plastics and CFRP are currently being widely used in the manufacture of boats and other marine vessels. Marine composites are also used in subsea applications as protection structures for subsea wellheads and valves.

Roofing is the process of covering the uppermost surface and supporting structures of a building with materials such as shingles, membranes, insulating glass, and cement. There are two main types of roofing defined by the pitch or slope of the roof: Steep-slope Roofing and Low-sloped or Flat Roofing. The roofing systems are mainly chosen based on the climatic conditions of the region. Proper roofing provides strength to the building structure and also mitigates the overall cost of maintaining the room temperature by avoiding the cost of air.

Antibacterial glass inhibits the multiplication of bacteria and fungi and is equipped with the capacity to kill 99.9 percent of the bacteria on its surface. This type of glass is suitable for structures in which hygiene requirements have high priority. They are used in various applications in hospitals, laboratories, spas, swimming pools, sports halls, nursing homes, bathrooms, dining rooms, chemists' shops, and others. Most vendors use silver, copper, zinc, and titanium amongst other metals, in the manufacturing of antibacterial glass. Antibacterial glass can also prevent the growth of bacteria such as Methicillin-Resistant Staphylococcus Aureus, which is resistant to certain antibiotics. They are also very effective against HAIs.

为了研究轴向荷载作用下CFRP (Carbon Fiber Reinforced Polymer)-钢管混凝土构件屈曲后的力学性能，利用有限元软件ABAQUS建立CFRP-钢管混凝土长、短柱有限元模型，并采用buckle 及riks 求解器对模型进行求解。通过将有限元模拟结果与现有试验以及解析公式计算结果相比较，验证有限元模型建立的合理性。之后调整有限元模型中CFRP 布置形式和CFRP厚度来考查其对整体构件抗屈曲性能的影响：CFRP厚度的变化对长、短构件临界荷载的影响甚微；对于短柱，随着环向CFRP层数的增加，钢管的局部屈曲得到了有效抑制，构件屈曲后极限承载力提高显著。而对于长柱构件，纵向布置CFRP可以有效提高构件屈曲后承载能力，随着纵向CFRP厚度的增加，屈曲后极限承载力呈线性增长。

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.

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.

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.

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.

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.