Reinforcement masonry structure

This chapter provides material properties and response criteria necessary to design facilities constructed of reinforced concrete, reinforced masonry, structural stcc and cold formed steel. Static and dynamic properties are covered for the materials used in these facilities. Allowable response criteria are covered for both... 

As regards to FRP reinforced masonry structures undergoing cyclical tensile and compression stress, such as those caused by seismic events and thermal variations, the masonry-FRP adhesion can extensively degrade over the life of the structure. In this regard, it may be necessary to insert the reinforcement into notches, aiming at preventing local instability that applies to mechanical connection devices. 

In all blast-resistant structures (steel, concrete, or masonry) special attention should be given to the integrity of connections between structural elements up to the point of maximum response. For example, it is important to prevent premature brittle failure of welded connections to avoid stress concentrations or notches at joints in steel structures and to provide ductile reinforcement detailing in concrete/masonry structure connections. For all materials, it is recommended that connections be designed to be stronger than the connected structural members such that the more ductile member will govern the design over the more brittle connection. 

Limit state design methods are used in blast resistant design. These methods provide a comprehensive, reliable and realistic means of predicting failure mechanisms and structural capacities. Limit state design methods for structural steel, cold formed steel, reinforced concrete and reinforced masonry are available. However, as of now, no similar design specification is available for aluminum structures. 

Masonry, both reinforced and unrein forced, is a common construction material in petrochemical facilities. However, unreinforced masonry is inappropriate in blast resistant design due to its limited strength and its nonductile failure mechanisms. Reinforced masonry walls with independent structural framing for vertical loads arc commonly used in blast resistant design. 

Although electro-osmosis systems for drying building materials (e.g. concrete or masonry block basements) are well known technology, at the time of writing (2006) this technology is in its infancy for corrosion control of reinforced concrete structures. 

Fibre reinforced polymer (FRP) composite materials for strengthening of existing masonry structures... 

ACI 440.7R-10 (2010). Guide for the Design and Construction of Externally Bonded Fibre-Reinforced Polymer Systems for Strengthening Unreinforced Masonry Structures. 

The second part of this book is devoted to current and potential applications of adhesive materials in construction. Chapter 6 deals with both the repair and the strengthening of concrete structures, covering applications ranging from non-structural patch repairs and resin overlays to externally bonded steel plate reinforcement. The theme of repair and strengthening is extended to applications involving steel, timber and masonry structures. A number of case histories are reviewed and discussed with reference to the successes and failures, and the results of allied research work are presented. In Chapter 7 a number of applications of adhesives in new construction are described, and specific examples are given. The final chapter. Chapter 8, examines the potential for future developments in adhesive usage. 

In Eq. (2.2), Wi stands for the weighing factor multiplied by the negative penalty score in order to reflect the negative effect of the corresponding structural deficiency on the potential performance of the inspected building and can take values of 0, 1, or 2. Parameter R represents the type of masonry construction and takes positive values in the case of confined (30 points) and reinforced masonry (60 points) buildings. 

Plastic composites are found to be effective in retrofitting masonry buildings to reduce seismic damage to remove seismic deficiency the thin layer of reinforcement (fibre reinforced composite sheet) applied to the wall (like wall paper) is shown to increase substantially the load carrying capacities of masonry walls [38] as well as of reinforced concrete structures, including columns and walls and beam-column joints [39]. 

ACI 440.3R-12 Guide Test Methods for Fiber-Reinforced Polymer (FRP) Composites for Reinforcing or Strengthening Concrete and Masonry Structures... 

The FRP reinforcement of masonry structures, along with improving the mechanical characteristics of the single structural members, allows for a large improvement in the structure undergoing seismic events and can be positively used in case they do not satisfy the safety requirements provided by the regulations in force concerning one or more limit states. 

The use of composite materials in a reinforcement project of masonry structures has to be backed by the following elements ... 

An interesting application of composite materials in the field of masonry structures concerns the reinforcement of vaults, which can be carried out over vaulted members with different geometries, such as the single or double curvature. From a static point of view, the stability of a vaulted structure is guaranteed when the curve of pressures, that is, the funicular polygon of permanent load and accidental load resting upon it, is transferred to the internal composite material of the central inertia core of each section. Until the eccentricity remains limited compared with the inertia central core. 

---