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Sponsored by Oldcastle® Architectural | By Tom Cuneio, ME
Of all the acronyms in the design and construction industry today, BIM (Building Information Management) has to be one of the most recognized. Many in the industry are enthralled by all the brightly colored visions of projects still on the drawing board, the opportunity to immediately grasp the overall impact of a proposed modification in one system, and the intense record-keeping capability that translates to far easier repairs and renovations afforded by such advanced modeling capabilities. And with good reason. BIM stands to revolutionize the design and construction process, strengthening the traditional three-sided paradigm of success— project quality, cost, and schedule. Masonry, however, has largely been left behind in the race to BIMify the industry. This article will discuss the masonry situation in terms of existing and emerging BIM and other modeling capabilities, as well as challenges and benefits of a modeling system for masonry. Also provided will be real life examples of masonry projects that have enjoyed the benefits of modeling.
The masonry trade is an extreme blend of old and new technology. Consider the situation in undeveloped countries such as Malawi, a small country in South East Africa. Roofs in this village are primarily constructed by lashing sticks together into a crude frame and then covering the frame with bundles of grass to provide minimal shelter from sun and rain. The homes are primarily constructed with mud brick. These bricks are dug from the native soil on site and then baked in a wood-fired oven, Photo courtesy of Oldcastle® Architectural BIM Comes to Masonry The time-honored trade gets closer to meaningful Building Information Management Sponsored by Oldcastle® Architectural | By Tom Cuneio, ME CONTINUING EDUCATION EARN ONE AIA/CES HSW learning unit (lu) Learning Objectives After reading this article, you should be able to: 1. Articulate the benefits of BIM to project cost, schedule, and quality. 2. Discuss the challenges that masonry faces in terms of meaningful modeling. 3. Explain the advantages that architects stand to gain as BIM for masonry is implemented. 4. Describe what architects can do now in using modeling to the fullest when specifying masonry products. To receive AIA/CES credit, you are required to read the entire article and pass the test. Go to ce.architecturalrecord.com for complete text and to take the test for free. AIA/CES COURSE #K1405M The new Museum at Prairiefire in Overland Park, Kansas, highlights the power of masonry BIM tools to budget, order, and build successfully. educational-advertisement 189Continuing Edu cation also on site, to remove some of the moisture. The end product is a brick that is only slightly stronger than a dirt clod. They are laid in running bond using mud as mortar. They dig a small hole on the site and periodically wet the hole to dig “mortar” for laying the brick. No cement or other additive is used.
Dimensional tolerance? Unit compressive strength? Type S or Type N? f’n? These are nowhere to be found. On the other hand, these dwellings illustrate the simple beauty of masonry and the ancient roots of the trade. These structures are surprisingly sound. They have high thermal mass, are termite proof, require no transportation of materials, are 100 percent recyclable, are locally mined and manufactured. In fact they surpass even our best efforts at being “green” and sustainable. One man can mine, manufacture, deliver, and install all the necessary components to build these structures—a remarkable feat.
Since its inception thousands of years ago, masonry has in many ways not changed. It is still practiced today in exactly the same form that it began so long ago. Even at its most basic state, masonry is still a very effective means of providing shelter and security for people all over the world. At the other end of the spectrum is masonry in the U.S. In addition to cost, aesthetics, and durability, our projects must meet standards for energy performance and sustainability, and they must be technology friendly. Those involved with masonry products today may likely spend their time with highend computer hardware, the latest in software developments, intricate algorithms and analytical methods. The push is on to develop something that has never occurred to those builders of mud huts but could prove invaluable in today’s world demanding complex projects— 3D models of masonry buildings to advance the art of BIM for masonry.
As most architects know, BIM is a process that involves the generation and management of digital representations of physical and functional characteristics of places. Building Information Models (BIMs) constitute files, which may incorporate proprietary data and formats. These files are exchanged or networked to facilitate decision-making about a project and its design. BIM extends the format to 3D, incorporating the three primary spatial dimensions of width, height, and depth with other dimensions, such as time and cost, taking the information to a fourth and fifth dimension. BIM is object oriented, and in order to understand BIM, an understanding of the object being modeled is necessary. Unlike CAD, which represents elements with lines that define its geometry, BIM creates smart objects that contain several levels of information, or parametric data, including geometry, material properties, color and texture, cost, source and distribution information, and manufacturer. Each element in the BIM model “knows” how it relates to other objects and to the design in general.
Designs are represented as combinations of objects, or assemblies that can be simple or very complex, and can be analyzed as systems or according to cost. Because BIM defines objects as parameters and in relation to other objects, if an object is changed or modified, related objects will automatically change as will the associated cost estimates as well as material tracking, ordering, and many other attributes.
Because each member of the design team from architects and engineers to contractors and owners adds discipline-specific data to the single shared model, information losses are reduced and a more detailed database is created about a complex structure. Use of BIM, then, extends beyond the initial planning and design phase of the project, to have value throughout the building life cycle, and to support such project stages as construction management, project management, facility operation, and beyond. Early adopters are enthusiastic and confident that the use of BIM will enhance a variety of functions including improved visualization and productivity; better coordination of construction documents; increased information about specific materials and quantities for estimating and bidding; dramatic savings in overall project schedule and costs. BIM advocates also point out that most of the data needed for building energy performance analysis exists and that building energy simulation is feasible from an accuracy, time, and cost standpoint.
That said, some industries are more BIMcompatible than others. In terms of structural building materials, the main focus has been on incorporating steel and reinforced concrete into BIM software. For years, structural steel and cast-in-place concrete have had software with 3D capabilities and substantial design information that has made it easy for BIM software developers to build on. Likewise, several BIM tools have been developed for wood and cold-formed steel. Why not masonry? Arguably, the reasons stem principally from the intricacy of masonry products themselves and the endless possibilities to combine these products into complex arrays.
One of the reasons masonry has not been included in BIM software is the sheer complexity of the material. For starters there is the problem of managing the large number of units possible in a commercial masonry project. A block job may have several hundred thousand units and a large brick job can have more than a million units. Each unit has a unique location and orientation in the model, making unit model building a huge labor task. A variety of bond patterns are available to arrange the units in the building and sometimes several patterns are combined. Beyond this, many options exist for material and several are typically combined in a single job. There may be natural stone, manufactured stone, clay brick, concrete masonry, and within each option there can be many colors and textures, making the models even more complex. If that weren’t enough of a challenge, an additional layer of complexity is added by shape variation. Consider a very simple case of a wall of 8816 standard concrete masonry units all in the same color and texture. Within that product there may be 75 percent solid units, bond beam units, open end units, double open end units, solid bottom units and on and Detailed masonry models are providing meaningful data in the BIM environment. Image courtesy of CAD BLOX LLC/Suffolk Construction on it goes. Finally, additional layers such as making the job ground face or adding bullnose corners compound the problem. One can easily appreciate how much information must be tracked in a quality masonry model to get useful data. Each of the layers of complexity described above impact cost, so unless they can be tracked in the model, accurate cost data cannot be generated.
The dynamics of modeling are such that it is relatively easy to model materials that represent a small number of dissimilar objects regardless of complexity. Consider a revolving door which likely has only a few instances. It is also not difficult to model a very large number of homogeneous items as is the case for hundreds of thousands of roof tiles. But for masonry models which have both large number and great variation, the task becomes exponentially complex—especially for architectural masonry.
Challenges abound in incorporating masonry into BIM, and there are no easy answers, and no short cuts, just as there is little value in a model unless it is high quality and can take into account the complex layers of data required. It is not difficult for BIM designers to generate data, even for masonry. The real challenge for modeling masonry is quality data. While a stretcher—a basic unit in the field of a wall—may have a given cost, a corner unit of the same material can be three or four times as expensive in some architectural applications. Accurately accounting for these variations in product is essential to generate useful Quantity Takeoff (QTO) data for masonry.
Analytical models do exist, however, to assist in the design and installation of architectural masonry products. A few proprietary services offer a host of advantages in reducing time, cost, and potential problems in building complicated masonry jobs. The landscape is also changing as masonry industry stakeholders join forces to collaborate on creating and implementing new generation BIM-M, or BIM for Masonry.
Post-bid commercial software modeling programs do exist to assist in the ordering and installation of architectural masonry products. The models help the project team understand the products, order them accurately, resolve design issues related to CMU, layout bond patterns, stage complex orders, and increase productivity in the field. Further, the software enables practitioners to troubleshoot unusual design conditions such as an atypical bond pattern, bullnoses, score patterns, multiple textures, cove bases, arches, radius walls, or all of the above. The most successful technologies build models one unit at a time, as is done in the field—an approach that allows effective handling of the complexity of glazed CMU, ground face CMU, stone veneer, or other types of prefinished masonry units. Multiple colors, multiple textures, and intricate bond patterns can be modeled as well. Coded models facilitate an understanding of how precisely to build difficult conditions, with 3D layout drawings showing all conditions in the model to increase productivity in the field. “The take off detail is invaluable of course,” says Rick Riley of Hoffman Cortes Masonry, about this type of model. “The shop drawings save time and material in the field. They are like having a set of instructions on the wall. The foreman can give a copy to the b’layers on the wall and not worry about what is being set.”
It is important to point out, however, that the complexity of this type of quality modeling is primarily a post-bid activity. Design time masonry modeling is still in development but is an achievable ambition which the industry is actively pursuing.
BIM-M, or BIM for Masonry, is in the works, with several funding organizations blazing the trail. The Mason Contractors Association of America (MCAA), the National Concrete Manufacturer’s Association (NCMA), the International Union of Bricklayers and Allied Craftworkers (BAC), Western States Clay Products Association, the International Masonry Institute (IMI), and The Masonry Society (TMS) are recommending that software developers include masonry in BIM software. Working with the Georgia Institute of Technology, the group has completed a roadmap to achieve that goal and is now working on realizing their vision, all with the help of industry individuals including masonry contractors, material suppliers, structural engineers, architects, and general contractors. Their rationale: If masonry is not included in BIM software as steel and precast concrete are, masonry may appear to be difficult to work with, and find itself in a bad position competitively.
Phase 2, which involves creating a digital library of masonry units and accessories in a common format, is currently ongoing. In subsequent phases, the group will prepare proposals for software vendors to include more masonry capabilities into their products and, ultimately, implement new software for the masonry industry. These efforts are slated to begin in 2015 and 2016, respectively. A firstgeneration BIM(-M) software for masonry is anticipated sometime in 2017 or 2018, with industry watchers maintaining it will have a significant impact on the way masonry buildings are designed, constructed, and maintained.
BIM has been dubbed a “game changer,” and as such opens the door to many advantages over conventional “longhand” techniques that have been part of the construction process for centuries. While many architects will probably never work on a project with the staggering convolution of a Disney Concert Hall, most will work on projects that require sophisticated 190 BIM Comes to masonry educational-advertisement ▲ Dynamics of Modeling Difficult to Model ▲ Easy to Model • Revolving Door (“low low”) • Roof Tiles (“high low”) • Decorative Precast Panels (“low high”) • Gray CMU, Brick (“high low”) Difficult to Model • Doors in a hospital (“high high”) Easy to Model • Architectural Masonry (“high high”) BRICK GRAY CMU ACMU # of objects # of unique objects 191Continuing Edu cation detailing. In these instances, which include most projects in today’s development portfolios, BIM can simplify an architect’s job in many ways.
Computerized models have great potential to reduce human error and if an effective planning effort has been made by each discipline and is carefully reviewed and shared, BIM has the potential to avoid or at least reduce mistakes. Orders can be extracted directly from a quality BIM model, providing an exact representation of unit types, colors, textures, and quantities. With confirmation of the accuracy of the model, the exact product order can be delivered, eliminating the usual waste factor in sizeable orders. Further, because the software can break down and provide a better understanding of the construction project, there is a smoother implementation by contractors and subcontractors.
Clash detection. Integral to BIM modeling, clash detection is possible because each discipline—structural, MEP engineering, environmental engineering, etc.—has created an independent model which is then integrated in a single multilevel model. Clash detection identifies where the separate models have incompatible parameters, or an out-of-order time sequence that might cause design changes, higher materials costs, and the accompanying cascade of schedule and budget overruns. In the past, clash detection was performed on site as opposed to in the design phase when constructability issues can be resolved before construction begins, saving vast sums of money and time and producing a better building.
Quantity takeoff. A key part of any project, take off and estimating has been a tedious, time-consuming task. In the masonry field, the traditional method has been to cost out a project longhand, and then add a margin to the bid based upon the complexity of the job to cover all the intricacies that hand calculations cannot account for. For complicated architectural jobs this margin can be as high as 25 to 30 percent to cover unforeseen conditions. Yet BIM modeling can substantially decrease the time and effort involved, and derive a more accurate result. Field experience is full of case studies that have followed the cost of contractors’ mistakes in estimating and ordering. In 2011, for example, designers of a Chicago Public School specified 67,000 ground face units, and subsequently followed two paths: the contractor’s cost numbers and ordering methods and a modeling program to determine the same issues. While the modeling effort provided what in hindsight was an accurate cost figure and ordering scheme, the designers went with the contractor’s decisions, and ended up requiring 12 add orders, additional mold set up fees and freight costs, and experiencing significant delays and color variation problems.
While prefabrication reduces field labor cost and time and increases accuracy in good quality construction, it requires highly reliable models to be successful. BIM models can achieve this level of accuracy via specifications, finishes, sequences, and a three-dimensional visual for each building component. Provided that BIM relates to fabricators’ software, building elements can be manufactured according to precise specifications and delivered to the jobsite on time, in many cases curtailing costly and timeconsuming field cutting. Since architectural masonry typically involves a manufacturerapplied design treatment to various faces and edges, like ground face or bullnose, it is essentially a very large prefabrication problem that is ideally suited to a BIM solution.
Synthesizing information from a number of disciplines, BIM has the capability to identify unique products, optimized for individual customers or projects, and for a faster, more efficient construction process in order to create better buildings with less effort. Masonry manufacturers typically have tremendous flexibility to produce exactly the right specialized unit to resolve just about any design condition but if these unique products are not located and accounted for during the QTO process, those units will never appear on the jobsite. This is another area where a BIM solution controls both the cost of masonry projects as well as the final aesthetic of the installation.Back