Innovations in Masonry: Rolled Bed Joint Reinforcement
What is Bed Joint Reinforcement?
Bed joint reinforcement is an easy solution to improve masonry veneer walls’ strength and structural performance significantly. It controls crack formation in masonry, increases the strength of masonry walls, significantly reduces damage in the case of earthquakes, and provides better durability.
Traditionally, bed joint reinforcement reinforces concrete masonry units (CMU) and other building materials, such as manufactured concrete stone. Research is currently being conducted that investigates the potential benefits of bed joint reinforcement in additional masonry applications, including clay brick, and using thinner reinforcement alternatives, like Bekaert’s Murfor® Compact, to reinforce masonry walls.
The National Concrete Masonry Association (NCMA) is implementing one of these research projects, focusing on the shrinkage cracks on a concrete brick wall. As stated in the project grant application: “For concrete masonry veneers, the combination of joint reinforcement and veneer ties are placed in the same bed joint and can result in congestion issues where there simply isn’t enough space to accommodate the placement of both embedded items and maintain adequate cover distances for strength and corrosion resistance.” Murfor® Compact and other alternatives are being tested as alternatives for less congested joints. The results will be published in 2022.
The Origin of Bed Joint Reinforcement
According to the NCMA’s TEK note 12-2B, joint reinforcement was “initially conceived primarily to control wall cracking associated with horizontal thermal or moisture shrinkage or expansion as an alternative to masonry headers when tying masonry wythes together.” Joint reinforcement in single and multi-wythe walls became standard practice in the 1960s. The next shift in the industry was in the 1990s, when horizontal and vertical reinforcement, mainly rebar and truss mesh, was used in all projects across North America, not just those in high seismic zones.
Uses of Bed Joint Reinforcement
Masons can use bed joint reinforcement in various places around a masonry project, including lintels, long walls, gable ends, stress concentrations around windows and door openings, and specialty masonry projects like perforated walls and stack bonded masonry. Masonry professionals can alleviate stress concentrations around windows and door openings by adding bed joint reinforcement, two layers above and below the openings. Bed joint reinforcement can also improve the stability of gables by reinforcing every two or three courses, depending on the material. For gables with a height of more than 26 ft (8 meters), it is recommended to reinforce the joints at 8 in (200mm) spacing.
Innovations in Bed Joint Reinforcement
Recently, new products have made bed joint reinforcement easier, more efficient, and more cost-effective with more resilient results. One such option is the Murfor® Compact, Bed Joint Reinforcement on a Roll. It is composed of 7 steel cords (E-35) or 14 steel cords (E-70) with an interwoven fiberglass roving and is made with Austenitic Stainless steel (Molybdenum-chromium-nickel alloy). This option has been specifically designed for exterior masonry, meets the ASTM A580 standard for Type 304 Stainless Steel, and with a thickness of 0.07 in (1.75 mm), it is suitable for all mortar joints between 1/4 and 3/8 inch.
Masons can use rolled bed joint reinforcement materials like Murfor® Compact and other comparable products to extend, and in some cases, eliminate expansion joints in brick masonry or extend movement joints in manufactured concrete stone. Masonry reinforcement prevents wide shrinkage cracks, resulting in micro cracks instead. It is also possible to increase the distance between the movement joints, and in some cases, eliminate them. Options like these can save time, money and can improve the appearance of the building.
Advantages to Rolled Bed Joint Reinforcement
The use of rolled bed joint reinforcement in masonry projects has several advantages that can be attractive to the modern-day mason. For one, options like Murfor® Compact or other comparable products offer faster and simpler installation than traditional bed joint reinforcement products. Because they are lightweight, they can be easier and safer to carry as well. Additionally, these products are designed to accommodate varying wall widths, making them accessible for most construction projects requiring basic bed joint reinforcement. Finally, products like these are compact and easier to transport than other bed joint reinforcement systems, which means shipping these materials to the jobsite can be more convenient and inexpensive than traditional alternatives.
Selecting the Appropriate Rolled Bed Joint Reinforcement Option for Your Next Project
Bed joint reinforcement has been standard practice in North America for the last five decades, with few updates to the products. Therefore, it is exciting for the masonry industry to learn more about new and innovative options available to mason contractors, including rolled bed joint reinforcement materials. When considering testing out a new product on your next jobsite, consider the alternatives to traditional bed joint reinforcement in manufactured concrete stone and further explore the value of having joint reinforcement in clay bricks. With the price of building materials rising and the growing trend of having more sustainable and less wasteful products, bed joint reinforcement on a roll is a great solution. To learn more about using Murfor® Compact on your next project or request a free sample, reach out to Jimm Milligan at email@example.com or visit: https://www.bekaert.com/murfor-compact.
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