Masonry Reinforcement and Accessory Metals for Masonry Wall Construction

Specifications for reinforcement and accessory metals used in the construction of masonry walls is provided by International Building Code (IBC 2009) and Building Requirements and Specification for Masonry Structures (ACI 530.1-11).
Various types of reinforcement and metal accessories is discussed in the following sections.
Reinforcement Placement in Masonry Wall
Fig.1: Reinforcement Placement in Masonry Wall
Reinforcement and Accessory Metals Employed in Masonry Wall
Fig.2: Reinforcement and Accessory Metals Employed in Masonry Wall

Masonry Reinforcement, its Types and Accessory Metals for Masonry Structure

Masonry reinforcement and accessories includes:
  • Steel reinforcement
  • Connectors
  • Sealants
  • Flashings
  • Coatings
  • Vapor and moisture barriers

Steel Reinforcement for Masonry Structure

Steel reinforcement used in masonry structure involves reinforcement bars, joint reinforcement, and deformed reinforcing wire.
Steel bars are utilized to improve both tension and compression strength of masonry structure.
Masonry bond beams, lintels, and walls are examples in which steel reinforcement are applied to improve tensile strength of the member whereas reinforcement bars are used in masonry column to increase its compression strength. Hot rolled deformed bars, which possess ribs on its surface to enhance bond strength, are employed in masonry structure.
As per ACI 530.1-11, the maximum reinforcement steel bar size is No.11. The restriction on the size of reinforcing bars depends on the accepted construction practice and performance of the masonry structure.
It is claimed that, using and distributing small size steel bars in masonry provides better performance compared with small number of large size reinforcement placed in the masonry structure. Figure-3 demonstrates installed deformed steel reinforcement bars in the masonry wall.
Deformed Steel Bars in Masonry Wall
Fig.3: Utilization of Deformed Steel Bars in Masonry Wall
The steel reinforcement bars are usually categorized based on minimum yield stress of the steel which employed to manufacture the steel bars. Both epoxy coated and zinc coated steel bars are permitted to use in masonry structures and they may be utilized when corrosion protected reinforcement are specified as per the design.
Both epoxy and zinc coat protect steel bars in severe condition and consequently increase the life span of the structure.
If steel bars are covered with epoxy coat, then it is required to increase its development length and it should be 1.5 times the development length of uncovered bars. In contrary, bars covered with zinc coat do not need to increase the development length because zinc provides the same property as uncoated bars.
It should be said that, delivering and installation of coated bars need considerable attention to avoid coating damages otherwise the purpose of steel coating will not be achieved. So, any damages experienced by steel coating need repair prior to installation.
Figure-4 and Figure-5 show epoxy coated and zinc coated steel bars respectively.
Epoxy Coated Steel Bars for Masonry Structures
Fig.4: Epoxy Coated Steel Bars for Masonry Structures
Zinc Coated Steel Bars for Masonry Structures
Fig.5: Zinc Coated Steel Bars for Masonry Structures
The fiber reinforced polymer bars can be employed in masonry structures as a replacement of both zinc and epoxy coated bars in aggressive environments.
Figure-6 provides different types of fiber reinforced polymer bar. The FRP bar are available in different sized and they are considerably light which is advantageous because it substantially decreases the cost of delivering, handling, and installation.
Various Types of FRP Bars for Masonry Structures
Fig.6: Various Types of FRP Bars for Masonry Structures
Regarding joint reinforcement, there are three types of joint reinforcement involves welded wire fabric, deformed reinforcing wire, and ladder or truss type joint reinforcement.
Joint reinforcement is provided for different reason for example increase the size of a panel, increase the spacing between movement joints, and control differential movements. Added to that, it improved horizontal bending and restricts cracks in masonry structure. Joint reinforcement applications are shown in Figure 7 and Figure 8.
Joint Reinforcement Applications in Masonry Structure Construction
Fig.7: Joint Reinforcement Applications in Masonry Structure Construction
Installation of Joint Reinforcement in Masonry Walls
Fig.8: Installation of Joint Reinforcement in Masonry Walls

Connectors for Construction of Masonry Structures

There are various types of connectors which are used to connect or secure two members or parts together. For instance, ties can joint two Wythe’s of masonry wall together and adjustable ties may be employed to make rooms for differential elevation in masonry bed joints.
Types of Adjustable Pintle Tie Used in Masonry Structure
Fig.9: Types of Adjustable Pintle Tie Used in Masonry Structure
Types of Veneer Tie Employed in Masonry Structure
Fig.10: Types of Veneer Tie Employed in Masonry Structure
Types of Connectors Used in Masonry Structure
Fig.11: Types of Connectors Used in Masonry Structure

Sealants in Masonry Walls

Sealants are employed to fill and seal the spaces or joints which are created deliberately in masonry walls for specific purposes. There are three major joints in masonry structures includes construction joints, expansion joints, and control joints.
Sealants are usually produced from manmade polymers such as latex, silicone, neoprene, and butyl rubber. The elastic property of sealant including compressibility is equal to ratio of minimum thickness to original thickness.
Based on the anticipated service life of sealants, deteriorated sealants need to be replaced by new ones. It is claimed that, ordinary life span of majority of sealants, which are placed at exterior face or walls are around seven year.
The main factor behind sealant deterioration is due to sealant exposure to ozone and ultraviolet light. This is because polymers which are utilized to manufacture sealants are damaged under such conditions.
Figure-12 illustrates the application of sealants in the masonry wall joint, and Figure-13 shows sealant before and after the masonry wall expansion.
Sealant in Masonry Wall Joints
Fig.12: Use of Sealant in Masonry Wall Joints
Sealant in Expansion Joints of Masonry Wall
Fig.13: Employing Sealant in Expansion Joints of Masonry Wall

Flashings for Construction of Masonry Walls

Flashing is changeable and adaptive watertight material that may be manufactured from copper, stainless steel, plastic, plastic coated aluminum, and rubberized asphalt.
The life service of metallic flashing is considerably longer than plastic flashing that is prone to tearing. Rubberized asphalt flashing, which adhere itself to the masonry, can be installed easily and demonstrate reasonable durability.
Flashings are installed at different location of masonry walls, for example, all interrupted drainage cavity, bottom of each story level, under the sills of windows and doors, and over lintels of windows and doors.
It is applied to drain water that penetrate external Wythe of masonry wall. Weep holes at spacing of around 61cm above the level of flashing.
Figure-14 shows the installation of flashing and weep hole exactly above it in masonry wall.
Installation of Flashing in Masonry Wall
Fig.14: Installation of Flashing in Masonry Wall

Coatings for Masonry Structures

Masonry structure Coating involves application of paints and water repellent coatings. Comparatively, the effect of water repellent admixture is better than that of water repellent coatings.
The latter cannot bridge considerably wide cracks but rather it traps water behind them and consequently damages behind coating will occur due to freezing and thawing affect.

Vapor and moisture barriers for Masonry Structures

Vapor barrier is a watertight membrane applied to prevent the vapor or water penetration into masonry walls and consequently avoid interstitial condensation inside the air space of drainage wall.
The vapor membrane is used for exterior face of inner Wythe wall in warm conditions whereas it is applied for the interior surface of outer Wythe in cold condition. This is because warm air around the structure can go though outer Wythe and condense within the inner Wythe while in cold condition warm air inside the building will pass through inner Wythe and condense in the cavity.
Vapor barrier are practically applied for outer face of inner Wythe.
Moisture barrier impedes water penetration into the masonry wall whereas it does not prevent vapor penetration and hence it allows condensation in air space of drainage wall.

Comments

Post a Comment

Popular posts from this blog

40+ Construction Tools List with Images for Building Construction

Image
Construction tools list for building construction works such as concrete, brick masonry, leveling, wood works, floor works, slab works, brick laying, plastering etc. is provided. Every construction tool is necessary to achieve good results in the whole project. Along with these tools, the workers should also use some safety tools to prevent them from the unexpected accidents. Construction Tools List for Building Construction Some important construction tools and their uses are listed below: Bolster Boning rod Brick hammer Bump cutter/screed Chisel Circular saw Concrete mixer Cordless drill Crowbar Digging bar End frames Float Gloves Hand saw Helmet Hoe Iron pan Jack plane Ladder Line and pins Mason’s square Measuring box Measuring tape Measuring wheel Pick axe Plumb bob Plumb rule Polishers Putty knife Rammer Rubber Boots Safety glasses Safety helmet Sand screen machine Scratchers Sledge hammer Spade Spirit level Straight edge brushes Til
Read more

Building Materials properties and their Importance in Construction

Image
Building materials or construction materials are the major requirement in this modern age of technology. There are many types of building materials used for different construction works. Properties of Building Materials For a material to be considered as building material, it should have required engineering properties suitable for construction works. These properties of building materials are responsible for its quality and capacity and helps to decide applications of these material. Such properties of building materials are categorized as follows. Physical properties Mechanical properties Chemical properties Electrical properties Magnetic properties Thermal properties Physical Properties of Building Materials These are the properties required to estimate the quality and condition of the material without any external force. The physical properties of engineering materials are as follows. Bulk density Porosity Durability Density Density index Specific gravity
Read more

How to Prevent Errors During Setting Out Building Plan on Ground?

Image
Setting out building plan on ground is one of the most significant steps in building constructions and any errors at this stage would cause considerable problems, if it is not tackled immediately. Errors During Setting Out Building Plan on Ground There are different types of errors that might be made when a structure is set out for example gross errors, systematic errors and random errors. These errors should be prevented and there are some measures to tackle these issues. These measures will be discussed in the following sections. Fig.1: Setting Out of Building Plan on Ground Fig.2: Setting Out Building Plan on Ground How to Prevent Errors During Setting Out of Building? Following are the different types of control that should be carried out to prevent any errors during setting out building plan on ground: Good practice in office On site control Equipment and staff Checks Marking the ground Use of grid offset Good Practice in Office To successfully set
Read more

Factors Affecting Selection of Foundation for Buildings?

Image
Factors which affect selection of foundation for a building can be many from the soil conditions to the type of structure and loads from the building. All the factors are considered during selection of foundation for durable building construction. Factors Affecting Selection of Foundation Following are the factors which affect the selection of suitable foundations for building construction: Loads from building Type of soil Type of structures in neighborhood Type of foundations 1. Loads from Building The first factor considered is loads from building on the foundation. This load is a combination of dead load and imposed loads on the buildings. Other loads such as wind loads, earthquake loads, snow loads etc. are also considered based on location. The quantity of loads depends on the type of structure, number of floors and material of construction. As the number of floors increases, the dead load and imposed loads also increase. Choice of material for construction su
Read more

Ceiling types used in Building Construction and their Applications

Image
Various types of ceiling are used in building construction. Applications, aesthetics, advantages and disadvantages of these types of ceilings are discussed in this article. The ceiling of a building form one of the most important structural elements it terms of functionality as well as creativity which in turn bring good aesthetics to the building interior. This document would help you understand ceilings that in turn would help you understand the most suitable options while undertaking either repair or renovation work of our building interior. The ceiling gains a definition, ” A part of a building which encloses and is exposed overhead in a room, protected shaft or circulation space.” It helps us to create an enclosure and separation between spaces. They provide perfect lighting in the room by controlling diffusion of light. It also controls the sound around a room by making the room sound proof. It, therefore, stops the passage of sound between the rooms. Now ceiling also po
Read more

WHAT IS VOLUME BATCHING OF CONCRETE AND HOW IT IS DONE IN FIELD?

Image
WHAT IS VOLUME BATCHING OF CONCRETE? Batching of concrete means measuring different ingredients of concrete (i.e. cement, sand, coarse aggregate and water) before mixing it. When this measurement is done on the basis of volume, we call it  Volume Batching . Below are mentioned some of important points to remember before adopting volume batching method in field. Volume batching is not a good method for measuring concrete materials. It is not applicable in case of reinforced concrete structure. This method of concrete batching may not be economical. It can be only used for unimportant concrete or for small concrete works. HOW VOLUME BATCHING IS DONE IN FIELD? Before batching concrete ingredients in terms of volume, we need to know two things. What is the relative proportion of concrete ingredients in terms of volume? What is the water-cement ratio? After knowing these two things you can proceed to batch concrete ingredients in field. The table shown below can be
Read more

HOW TO DETERMINE DEPTH OF FOUNDATION

Image
Many factors affects the determination of depth of foundation. Calculation for foundation depth is done based on type of soil, ground water table, loads from structure, bearing capacity of soil and other factors. General factors to be considered for determining depth of foundation are: 1. Load applied from structure to the foundation 2. Bearing capacity of soil 3. Depth of water level below the ground surface 4. Types of soil and depth of layers in case of layered soil 5. Depth of adjacent foundation The minimum depth of foundation should be considered to ensure that the soil is having the required safe bearing capacity as assumed in the design. However, it is advised to carry out soil investigation before deciding on depth of foundation. Soil investigation report will suggest the foundation depth based on the type of structure, soil properties, depth of water table, and all other variable that should be considered. Soil investigation report provides bearing capacity of
Read more

Construction Project Management Softwares

Image
Construction PM Software A new wave of web and cloud apps are streamlining communication, simplifying document management, and improving efficiency in construction management.  Here are some of top construction management tools: Smartsheet Smartsheet  is a spreadsheet-inspired work management tool with robust collaboration and communication features. With pre-built construction templates, it’s easy to create a timeline, track progress, manage documents, and organize the details. Gantt charts are automatically created and auto-adjust every time a change is made, so you can share the most up-to-date timeline with team members or stakeholders. You can upload files from your computer, Google Drive, Box, Dropbox, Evernote, or add a web URL, creating a central repository for all project documentation and contracts. Team members can have discussions directly in the sheet and set reminders and alerts, so everyone is on the same page. And lastly, Smartsheet integrates with ot
Read more

Methods of underpinning, Procedure and Applications in Foundation Strengthening

Image
Underpinning is a method for repair and strengthening of building foundations. Underpinning methods, procedures and their applications in strengthening of different types of foundations is discussed in this article. There are situations where a failure in foundation or footing happens unexpectedly after the completion of whole structure (both sub and superstructure). Under such emergency situation, a remedial method has to be suggested to regain the structural stability. The  method of underpinning  help to strengthen the foundation of an existing building or any other infrastructure. These involve installation of permanent or temporary support to an already held foundation so that additional depth and bearing capacity is achieved. Selection of Underpinning Methods Underpinning methods are selected based on age of structure and types of works involved. Structure categories based on its age: Ancient Structures :Age greater than 150 years Recent Structures : Age between 5
Read more

Methods for Calculating Cost of Engineering Consultant Services

Image
here are several methods by which calculation of engineering consultant services cost can be carried out in construction. It is possible to employ various charging approach at different phase of the consultant services. The application of each method or combination of methods is dependent on nature, scope and complexity of the required engineering services. In this article, these charging consulting services are discussed. Following are the topics discussed for calculating cost of engineering services or consulting services in construction: What are the factors that affect the engineering service cost? Methods for charging engineering services What are the Factors that affect the Engineering Service Cost in Construction? There are various factors that control the cost of engineering services required for a specific project. These factors are outlined below: The conditions at project site. Degree of danger that may be encountered and exposure possibility. System of pr
Read more