Reinforced Drapery Meshes: A Design Method Accounting for Retaining Ropes Contribution

Reinforced drapery meshes, both secured and pinned, constitute a compelling solution for rockfall risk mitigation on rock slopes facing structures and infrastructures. They consist of steel wire mesh panels combined with a systematic anchoring pattern. In secured drapery systems, the anchors are connected to each other and to the net through ropes. The system prevents both global instability of the surficial part of the slope thanks to the anchors and local instability by confining small detached fragments in delimited mesh sections. The mesh is generally designed with mechanical resistance derived from the puncturing force–displacement behavior observed during a standardized laboratory test. Despite the fact that a codified design method has not yet been defined, the mesh is generally verified without considering the presence of the ropes. In the present work, an enhanced design method is introduced that accounts for retaining ropes, with the aim of achieving a confining effect similar to the constraints adopted in laboratory tests. In addition, the rope pattern enables the consideration of portions of mesh smaller than pinned drapery systems. In the proposed method, rope elongation is limited such that failure of the mesh near the anchor plate is prevented. The proposed design assessment reveals that the presence of ropes provides possible cost reductions in the choice of the mesh type.

The Flexural Behavior of Ferrocement Composite Hollow-Cored Sections

This study will study the influence of several types of metal and non-metal mesh reinforcement materials on the flexural behavior of reinforced concrete hollow-cored sections as a viable alternative to traditional reinforced concrete sections. Compared with the traditional reinforced concrete part, the weight of the test part is lighter. In order to strengthen these hollow-cored sections, three types of steel mesh, Welded wire mesh, expanded steel wire mesh and tenax mesh with various layers are used. An intensive experiment plan was carried out on the test samples. Ten slabs with dimensions of 500 mm*2000 mm*120 mm were cast and tested until they failed under flexural load. Record and observe the deformation characteristics and cracking behavior of each sample during the loading process. According to the results, high ultimate load and serviceability load, crack resistance control, high ductility and strong energy absorption characteristics have been obtained. This has the chance to be a true construction benefit to developed and poor countries. The use of double-layer of expanded steel mesh as the additional reinforcement of the main steel can achieve the best performance of the reinforced concrete hollow-cored section.

An Experimental Study on Strengthening of Reinforced Concrete Flexural Members using Steel Wire Mesh

Reinforcing reinforced concrete (RC) beams with galvanized welded steel wire mesh is one of the latest technologies applied in retrofitting. For each sample, the experimental evaluation of 18 small reinforced concrete beam samples with a total length of 1200 mm was carried out to study the bending strength under static load conditions. Experimental testing has been carried out to the activated failure mode, with 11 reinforced samples, 4 integrally cast control beams and three original control beams. Based on the test variables, namely SWM characteristics and connection mechanism, the reinforced beams are divided into two groups A and B. This study also clarified the bending resistance, ductility, stiffness, crack width and deflection. According to the test results obtained, all reinforced beams are designed to fail ductilely. The first group of reinforced beams recovered to an average of 110% of the bearing capacity of the original control beam, while the second group of reinforced beams recovered to an average of 163%. Furthermore, it was found that the reinforcement beam functions in the same way as the general control beam and works as a unit. Therefore, the bottom line is that this reinforcement technology can be used confidently in real-life applications, especially in low- cost buildings.

Slope stabilisation using high-tensile stainless-steel wire mesh

Slope stabilisation systems with meshes made of high-tensile steel wire have been in use for 20 years and have proven to be reliable systems on loose rock and soil slopes. The optimization of the nailing pattern thanks to the high load bearing capacity of the system permits a reduction of the overall costs and represents an economical solution as well as an ecological solution. The expected service life with regards to corrosion depends, in addition to the corrosion protection used, on the environmental conditions and the corresponding chemical wear. The definition of aggressive corrosive environments for slope stabilisation projects are for example: coastlines by the sea, aggressive ground (low pH-value, sulphur content) and roads with de-icing (salt). If the micro-climatic conditions on site are known, systems made of stainless steel can be installed to counteract the aggressiveness and keep up a long service life. Stainless steel is a steel alloy, with a minimum of 10.5% chromium and less than 1.2% carbon content. The chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'. This prevents any further corrosion of the surface. In this contribution the pilot project for stainless steel-based slope stabilisation is presented, which has been installed 14 years ago in an aggressive environment, along the coastline in the UK. It was installed in 2007, with a stainless high-tensile steel wire mesh. Not only does the slope stabilisation mesh have to be made out of stainless steel, the additional components have to present the same protection to avoid the phenomenon of bi-metallic corrosion. Therefore, the nails, spike plates and press claws were as well made of stainless steel. After fourteen years, the slope is still undisturbed and the material in good conditions although exposed constantly to the sea breeze.