Accelerating the rate of masonry block wall construction from around 200 8-in. blocks a day for a mason and a tender to about the same number in one hour is the quantum leap that ProStack developers attribute to their system. Rapid block placement for code-compliant structures, they add, is achieved by two distinct ProStack techniques: The dry stack method requires no joint mortar; and, the WetStack system entails application of a thin ProStack ASTM 3-270 type S/M mortar using a high-speed applicator, rather than a trowel. Both methods employ ProStack ASTM C-90 approved block.
A complete set of structural tests has demonstrated the merits of both construction methods, which conform in all respects to ACI, ASCE, and IBC requirements for unreinforced, reinforced grouted, and partially grouted walls. Mandatory testing has been completed on ProStack Precision Block and Mortar, plus completed wall assemblies. Thus, ProStack can be specified by architects and engineers in full confidence that the patented system satisfies code requirements, as well as National Concrete Masonry Association guidelines, applicable to conventional masonry block construction.
The fastest means to build with masonry are provided by ProStack's dry-stack method, lacking mortar between joints, where wall assemblies are grouted solid. The mortared option, WetStacking, allows designers and builders to erect walls using standard design tables and masonry construction software. Instead of a ? -in. mortar joint and trowel placement, however, ProStack features a joint of ? in. (or less) and mortar application via simple grout bag or a self-contained auger pumping system.
The WetStack block system replaces conventional horizontal wire reinforcement every 16 inches on center with reinforced bond beams on 8-ft. centers (with #4 rebar) and 10-ft. centers (with #5 rebar). The ProStack mortared masonry method falls under ACI 530 Specification for Masonry Structures.
WetStack Block is produced on widely available standard block equipment. Fabricating the block to a height tolerance of +/- 1/64 in. (about the thickness of a business card, eight times more stringent than the ?-in. tolerance of standard CMU) ensures structural height control. Moreover, as the block machine forms various joint styles, e.g., rake, concave, or 1/8-in. tooled for stone-masonry, WetStack units can be offered in a range of joint treatments to suit aesthetic demands. Joint-treatment options apply to smooth-face and architectural split- or ground-face block.
ProStack Masonry Wall Systems are supplied by licensees, generally local concrete block producers in New England and Southeastern states. Since its development was first undertaken in 2004, ProStack has been used to construct below and above-grade structures, including hotels, aircraft hangars, and apartment complexes, among a variety of commercial and institutional projects. Foundation walls Û dry stacked and grouted solid Û for the Hilton Garden Inn in New Hampshire comprised the first ProStack commercial application in November 2004. Since then, dry stacking ProStack Precision Block has proved invaluable, especially for construction during harsh New England winters that would preclude use of standard mortared masonry. Accordingly, walls for the Marriott Courtyard in Manchester, N.H., were dry stacked; when the weather broke, cells were grouted and the filled walls blanketed.
Among builders who consider ProStack a significant advance for masonry construction is Mike McGee, vice president of Monroe, N.C.-based McGee Brothers: I have been in the masonry contracting business for decades; and ProStack, frankly, is the first new idea that looks to benefit the industry in a big way. We wet stacked the ProStack Split-Face units in a 36- _ 50- _ 12-ft. structure and were pleasantly surprised by how easy it was to build÷clean, fast÷and looked great. It took just over a day and a half Û with no trowels, no mortar pans.
Echoing that observation is Jason Dove, president of Anderson, S.C.-based Milestone Masonry, who says, I have been in the commercial masonry industry for over 10 years, building big box stores and retail shopping centers in the Southeast. After erecting several walls with ProStack, I believe that it will become the standard in five years. My crews were building walls in half the time the very first day with ProStack, and they got faster each day. Û www.ProStackBlock.com; toll free: 888/ 263-6593