The Paving Surface Selector. A guide to the applications and economics of commercial and municipal grade paving solutions

Transcription

1 The Paving Surface Selector A guide to the applications and economics of commercial and municipal grade paving solutions

2 Introduction This guide has been designed to provide a general, qualitative comparison of the key characteristics which define the three primary decorative paving solutions. It will allow you to evaluate the use of pavers, stamped concrete and structured asphalt based on dynamics relating to cost, aesthetics, application constraints, and environmental impact. Each of these technologies has its own unique strengths and weaknesses. Understanding the limitations of each relative to the issues addressed here will help you to choose the technology best suited to your specific project(s). Many of the rating conclusions here may be subject to debate. This document is not intended to be objective, as many of the experiences and opinions, and therefore biases, of the author have been used to form these conclusions. The information is presented as accurately as good faith will allow. To use the guide, simply review each factor section. Choose the issues which apply to the project, or projects, you are planning, and compare the performance of the three technologies by reading horizontally across the page. You ll see how each fares, and how each performs relative to the other two. At the end of each section, you will have formed a best choice. Enter your best choice for each factor section in the margin at right. In working through the guide, you may find that certain factors will take precedence over all others, literally eliminating the other two options. For example, if you are creating a small, highly customized walk in an extremely confined area, it would not be cost-justifiable to try to bring the equipment necessary to use concrete or asphalt pavers would be the choice by default. If you have any questions about this guide or the structured asphalt applications described herein, please call 1 (866) Note: Background photo for all sections shows an actual StreetPrint structured asphalt installation.

3 Environmental Factors Environmental Factors The chemical make-up of the surface materials and the characteristics unique to the installation of each solution will cause each to react very differently over time. As you can see, the geography of a given installation will play a major role in selecting the best option. Freeze/Thaw Cycles Rating: 6 Salt Exposure Chemical Exposure Rating: 5 ing may cause cracking. and may become flooded at times. and petrochemical exposure. nent staining can occur. Stamped Concrete Additional cracking is evident around edging where water may have entered, expanding and contracting with freeze/ thaw cycles and damaging the surface. This example was photographed in the Northeastern US approximately 2½ years after construction. Brick Shifting of pavers along the edge (shown here) and elsewhere in the interior may be related to water entry between pavers followed by subsequent freeze/thaw cycles. This example was photographed in the Northeastern US; age of construction is not known. Stamped Concrete Structured Asphalt Rating: 5 Rating: 9 Expansion joints provide controlled movement during freeze/thaw cycles. While water is not initially absorbed through the rigid surface, water may be absorbed through expansion joints and minor cracks where freezing may cause increased cracking and movement. Rating: 5 Rating: 9 Stamped concrete, may be seriously degraded by repeated exposure to salt. Surface coatings may add some degree of resistance to salt, but the substrate material is still subject to failure. This should be considered when specifying where snow removal is an issue or in coastal areas where salt air and water are present. Rating: 8 Rating: 7 Stamped concrete, with surface coatings, can be resistant to many petroleum-based chemicals (uncoated or worn concrete may be permanently stained). This technology may be an effective choice for parking applications where the climate makes snow removal (salt exposure) unlikely. Sealed structured asphalt, a flexible surface, offers excellent durability during freeze/thaw cycles. Polymer-based continuous surface prevents water absorption. flexible substrate allows the material to expand and contract without degrading the surface. The chemical composition of the structured asphalt substrate is not subject to degradation from salt. Polymer-based surface coatings are also salt-resistant. Structured asphalt provides outstanding durability in parking lot applications where snow removal is a frequent issue or in coastal areas where surface is repeatedly exposed to salt air and water. Structured asphalt offers good resistance to chemicals and petrochemicals. While the substrate can be degraded by some petroleum-based chemicals, the polymer coatings in this technology offer a continuous, non-porous barrier. This technology is an excellent overall choice for parking applications.

4 Application Factors Application Factors This section looks at some of the most common limiting factors as they relate to the three primary decorative paving technologies. Since each has limitations unique to specific application situations, we have high- Downtime Rating: 4 The period of time for the installation of pavers can be significant, particularly when applied to a large-scale project. While there is no curing time required, the foundation preparation and installation can cause prolonged downtime when pavers are used in a replacement surface project. In a new construction situation, this downtime may be less critical, being contained within the scope of the overall project schedule. Multiple Textures Rating: 10 As a modular surface, no mass-application technology can surpass pavers. A wide variety of surface materials can be designed into a given project and borders can be of virtually any size or configuration. Again, cost will be the limiting factor here. fic drawbacks could heavily influence your decision. Structured asphalt is ideal for replacement surface projects. Foundation preparation can be less complex than that of other surfaces since the substrate is flexible. The base asphalt is heated for application purposes. Once cool, it returns essentially to full strength. Since structuring (imprinting the texture) simply reheats the substrate, downtime is very short. Poly/cement sealer can be applied the same day. Tight Areas Rating: 8 As a modular technology, brick/stone pavers are ideal for tight area applications. Materials are easy to get into difficult spots, and their component-based nature provides excellent tailoring to irregular topographies. Because extensive cutting is required, installation can be labor intensive and expensive. Hardness Rating: 8 Brick, and particularly, stone, provide a very hard surface. Heavy items, standing for a long period of time, (even with sharp pressure points of contact) will not usually damage these surfaces. The application process for structured asphalt does not lend itself well to tight application areas. The equipment and Structured asphalt s protective poly/ cement coating fortifies the hardness of the surface. Still, heavy items, standing on sharp pressure points for a long period of time may leave impressions.

5 Aesthetic Factors Aesthetic Factors Properly installed, each of the three technologies examined here will produce an attractive decorative effect. The two mass application technologies have been designed to resemble real brick or stone pavers, and materials and production techniques have been refined significantly over the years. Aesthetics must be considered from both the immediate and the long-term perspective when factored with the other parameters addressed in this guide. Initial Appearance & Design Rating: 10 Real brick, stone or concrete pavers can produce an excellent initial field expertise in assembly. Stamped Concrete This expansion joint shows an obvious disruption to the non-linear pattern of the brick effect. This constraining factor of stamped concrete can spoil the illusion of a realistic brick surface. Note the early signs of damage to the joint which may be related to water entry followed by subsequent freeze/thaw cycles. This example was photographed in the Northeastern US approximately 2½ years after construction. Stamped Concrete Structured Asphalt Rating: 7 Rating: 9 Stamped concrete is, by its nature, a mass application. Appearance can be very good, however, depending on the skill level of the applicator. The single greatest aesthetic drawback lies in the required incorporation of expansion joints. These joints are difficult to hide in random patterning, and can seriously diminish authenticity of the final effect. There is limited potential for design variability based on the constraints of a pouring and curing technology. The surface must be worked while setting, and cannot be reworked after curing. An unsatisfactory result must be physically broken and removed so the process can be repeated virtually from the start. Structured asphalt is a mass application like stamped concrete (as opposed to the modular solution presented by brick, stone or concrete pavers). The appearance of structured asphalt can be extremely faithful to the brick or stone effect for several reasons. First, because asphalt is a flexible, continuous surface, there is no need for expansion joints which detract dramatically from the realism of the effect. In applying the desired pattern to asphalt, an unsatisfactory effect can immediately be reworked by reheating the asphalt and re-applying the stencil. Aesthetic Effects of Wear & Repair this is generally considered acceptable. Rating: 6 Rating: 9 Stamped concrete, as a flat, continuous surface, is resistant to damage from snow removal equipment, but in warmer climates, the sun may permanently bleach color from the surface. Ground movement may crack the surface or cause shifting between pads at expansion joints. Repairs can be difficult and costly, as they require removal of damaged area and complete re-pouring and re-stamping. Repaired areas are often readily apparent and can be aesthetically undesirable. Again the illusion of a modular surface can suffer greatly. Structured asphalt, as a flat, continuous surface, is resistant to damage from snow removal equipment. Color, applied in the poly/cement sealing coatings, resists bleaching from the sun. The flexible substrate is also resistant to damage caused by ground movement. When surface damage or wear do become apparent, seamless, nearly undetectable repairs can be made by reheating and re-stencilling the existing substrate. In cases of simple wear, resurfacing with the poly/cement sealer will inexpensively restore color and texture to virtually original condition.

6 Cost Factors Cost Factors Each of the three technologies has very unique characteristics relating to the scale of a given project. Surface installations which require a greater degree of hand labor, set-up, and/or higher materials and shipping costs may be affected by diminishing return dynamics for smaller projects. In some cases, the decorative paving surface will be small enough that the factor of cost-per-square-foot in general terms, may become irrelevant. Large Continuous Coverage (10,000+ sq. ft.) Rating: 3 High materials costs (and shipping costs), combined with labor intensive, manual assembly make pavers a very expensive choice in large continuous coverage applications. Asphalt, a flexible surface, doesn t require the material thickness of concrete for support. Automated substrate placement and patterning is very fast Medium Continuous Coverage (500 to 10,000 sq. ft.) Small Continuous Coverage (500- sq. ft.) Rating: 4 As the project area becomes smaller, the time associated with laying pavers becomes less of a cost factor. Still, with a project in this size range, the process is labor intensive and costly. Rating: 6 Trim Applications Rating: 7 become more cost-efficient for smaller projects. However, this technology is a costly, time intensive, hand operation in any configuration and may require extensive hand cutting and fitting. are well suited to complex and intricate trim applications. Depending on the nature of the project, costefficiency may not be as critical an issue, particularly when project scope is limited. Decorative Accents Rating: 10, brick or concrete, are ideally suited to this application providing the kind of ultimate flexibility that only a true modular configuration can. Unit cost is a minor factor in this application. set pouring efficiency. fficiencies for a The process of laying and imprinting structured asphalt is still very efficient in this coverage range. Set-up is relatively inexpensive and patterning is very rapid, keeping the process costeffective. Structured asphalt, with its simple setup, is still cost-effective for smaller jobs. Cost-efficiency is only reduced due to the short duration of the application process which limits leveraging of set- Structured asphalt, as a mass application, is not cost effective for stand-alone decorative accents. Note: adding decorative accents within a larger project, cost efficiency may rate as high as 10. Environmental Factors Application Factors Aesthetic Factors Cost Factors

7 Integrated Paving Concepts pmb Peace Portal Dr. Blaine, wa To learn more about StreetPrint structured asphalt, please call or visit our website at