Characteristics of PVC Coated Welded Wire Mesh Fiber Reinforced Concrete

Fiber concrete containing fibrous materials is manufactured to improve the low tensile strength of concrete and its brittle properties. In this research, fiber obtained from PVC coated welded wire mesh with diameter of 1 mm was utilized. There were several variations of fiber concrete samples made. Samples were subjected to tensile and compressive strength tests. The elastic modulus was measured by using extensometer and strain-stress gauges. The results show that the incorporation of PVC coated welded wire mesh increases the tensile strength of concrete, when the percentage of the fiber is 1.5%, with the length of 3.6cm, and the interlocking of 1.2cm. However, the compressive strength is slightly reduced from the normal ones. The elastic modulus results show that the introduction of PVC coated welded wire mesh tends to reduce the flexibility, as the value reduced 15-50% as compared to the normal ones without any fiber

An Experimental Study on the Structural Behaviors of HIRC Beams Using Nickel-Titanium SMA Wires

This paper deals with structural behavior of highly intelligent reinforced concrete (hereinafter, HIRC) beams actuated by embedded shape memory alloy wires through an extensive experimental program. The experiments were conducted under the monotonic loading condition. Based on the structural experiments involving HIRC, load-temperature deflection curve, ductility-effective depth, recovery, crack patterns, and failure mode comparison were made for investigative purposes. The results of the experiments confirmed that the ductility, recovery rates, and other properties of the HIRC specimens reinforced with SMA, wire mesh, fiber, and admixtures were superior to those of the unreinforced RCBs. The experimental results indicate that a good recovery rate in the HIRC beams could be obtained when the SMA wires were heated. Accordingly, the SMA wires could be potentially used for structural self-rehabilitation capability and deformation monitoring in architecture and civil structures.

Processing of polycaprolactone and hydroxyapatite to fabricate graded electrospun composites for tendon-bone interface regeneration

The process of electrospinning is utilized with different approaches including conventional electrospinning, extrusion electrospinning, and electroblowing to form nanofibrous meshes and composites. Here, we report on the quality and properties of spatially graded polycaprolactone (PCL) and nano-hydroxyapatite (nHA) composite meshes fabricated with multiple-spinneret electrospinning. The composite meshes were characterized in terms of the amount of spatially allocated nHA concentration across the mesh, fiber diameter, porosity, pore size, and hydrophilicity of meshes. Results show that linearly and continuously varying nHA concentration distribution, i.e. graded structure, can be accomplished across the mesh thickness using multiple-spinneret electrospinning, which is in accordance with the change of mineral concentration observed in native tendon-bone interface. Furthermore, incorporation of nanoparticles into nanofibers led to increased fiber diameter as depicted by a shift in fiber diameter distribution, a significant increase in mean fiber diameter from 361±9 nm to 459±21 nm, and an increase in contact angle from 120.01±2.77° to 115.24±1.17°. These findings suggest that the composite meshes formed in this study could serve as model systems to be used as scaffolds in tendon-bone tissue engineering application in particular, and for other tissue-tissue interfaces in a broader context.

Different Performance of Foam Concrete Caused by Two Types of Fiber

400kg/m3 apparent density foam concrete consists of protein foaming agent, ordinary Portland cement and two types of polypropylene fibers is made in this study. The effects of two types of fibers (polypropylene linear fiber and polypropylene mesh fiber) on the compressive strength, flexural strength and water absorption of the foam concrete were investigated. The results showed the difference of the water absorption of the foam concrete with addition of the two types of fibers is not significant, but the difference of the compressive strength and flexural strength is clear. Moderate addition of fibers could improve the strength of the foam concrete. As compared with control, the compressive strength and flexural strength increased by as high as 60.7% and 71.2%, respectively. From the experimental results, it is clear that polypropylene linear fiber has advantage of compressive strength and flexural strength over polypropylene mesh fiber when mixed with foam concrete.