How much surface preparation is required for an overlay?
The degree of surface preparation for an overlay is dependent on the condition and type of the existing pavement. Generally, the existing pavement should be structurally sound, level, clean and capable of bonding to the overlay.
What is concrete overlay?
A concrete overlay is a specially designed, thin layer of polymer modified concrete used to resurface or repair existing concrete. They can be applied from feather edge thin up to 2" thick in some cases. Overlays can be stamped, broom finished, or left smooth. Most all manufactures of concrete overlay products have their own proprietary blends.
What is overlay paving?
Overlays (either structural or non-structural) make up a large portion of the roadway paving done today. The degree of surface preparation for an overlay is dependent on the condition and type of the existing pavement.
How do you maintain the life of a pavement overlay?
To maximize an overlays useful life, failed sections of the existing pavements should be patched or replaced and existing pavement cracks should be filled. At most, overlays are designed to add only some structural support; the remaining structural support must reside in the existing pavement.
What is pavement overlay?
Generally, pavement overlays are used to restore surface course (both HMA and PCC) characteristics (such as smoothness, friction and aesthetics) or add structural support to an existing pavement. However, even a structural overlay needs to be placed on a structurally sound base.
Why do you need a tack coat before overlaying?
Before overlaying, a tack coat should be placed on an existing pavement to ensure adequate bonding of the overlay to the existing pavement surface. Proper tack coat application can be critical to long-term pavement performance.
What is a prelevel paver?
Leveling courses (or prelevel) are initial lifts placed directly on to the existing pavement to fill low spots in the pavement (Figure 2). Typically, pavers use an automatic screed control, which keeps the screed tow point constant regardless of the tractor unit vertical position. This allows the paver to drive over a rough, uneven pavement yet place a relatively smooth lift with extra HMA making up for low spots in the existing pavement.
Is milling a good alternative to leveling?
For many situations, milling may be a superior alternative to a leveling course. Leveling course quantities are difficult to accurately estimate and leveling course thicknesses are usually small, precluding the use of nuclear gauge density testing. Thus, adequate mix density is difficult to achieve and measure. In some overlay projects a combination of milling and leveling course application may be best.
Can you air dry asphalt before PCC?
If water blasting is used, the surface must be allowed to air dry before the PCC is placed. Once the flexible pavement surface is clean, it must be kept clean until the bonded overlay is placed. Dust, dirt and debris that falls or blows onto the asphalt surface must be removed.
Can HMA overlay be placed on PCC?
Placing a HMA overlay on a jointed or cracked PCC pavement involves some special considerations in addition to the usual repair and leveling. Jointed plain concrete pavement (JPCP) is placed in discrete slabs and both JPCP and continuously reinforced concrete pavement (CRCP) tend to crack into discrete sections.These slabs/sections tend to move as individual units. Although HMA overlays can accommodate small differential subgrade movement without cracking, the large differential movement at slab and crack interfaces is great enough to crack a HMA overlay (called reflection cracking ). There are several techniques to prevent (or at least delay the onset of) reflection cracking:
What can you use concrete overlays for?
You can use them to repair concrete, for ultra thin toppings, for decorative stamping and staining, and to level a floor that's tipped or pitched the wrong way.
How thick should a concrete overlay be?
This is how thick a concrete overlay should be for these applications: 1 Resurfacing an interior concrete floor - 1/16" - 1/8" 2 Resurfacing a concrete walk, driveway, patio, or pool deck - 1/8" - 3/8" (includes stampable) 3 Self-leveling underlayment - 1/8" up to 2" 4 Self-leveling overlay (including polishable) - 1/4" up to 2"
Can you overlay concrete over a crack?
If the existing concrete you're about to overlay is still moving (settling or heaving) then the new concrete overlay will most likely crack right over the repaired cracks. Some concrete overlays have to be kept wet soon after they cure so they don't cure too fast.
Can concrete overlays be stamped?
Overlays can be stamped, broom finished, or left smooth. Most all manufactures of concrete overlay products have their own proprietary blends. All you really need to know is there's a blend of Portland cements, various aggregates and polymer resins. It's the polymers in these overlays that make them special.
Can you use concrete overlay on countertops?
If you're going to use a concrete overlay on your countertops, you're either going to go very thin and smooth or stamp it with a pattern. For thin and smooth - Use Tru-Impressions Canvas Microtopping, it comes in light grey and white. You can dye it with color or stain it after it's cured.
WHAT IS THE BEST CONCRETE PATIO COATING?
Compare types of systems and learn which one is right for your patio project.
PATIO FINISHES FOR EXISTING CONCRETE
If you are looking to add an element of your own personality to your patio, there are a variety of options available. You can use color, patterns, textures, or even borders to take your design to the next level.
HOW MUCH WILL IT COST?
The cost of resurfacing varies on the detail and size of your surface. It is a more cost-effective option than removing the existing concrete and pouring a new slab. A new pour patio can cost anywhere from $3 - $15, or more, per sq. ft. depending on the size and detail of the design that is being installed.
PATIO RESURFACING IDEAS
How do you put a fresh finish on an existing concrete patio, yet make it look worn and weathered? For these homeowners in Escondido, Calif., the solution was a stamped concrete overlay replicating weathered wood and brick, resulting in a new surface with a naturally distressed look.
Highlights
A multilevel model was developed to model evolution of asphalt overlay roughness.
Abstract
The objective of this study is to investigate the effect of overlay thickness, overlay material and pre-overlay treatment on roughness evolution of asphalt overlay in the Long-term Pavement Performance (LTPP) SPS-5 experiment. Roughness data collected from SPS-5 experimental sites has a clustered longitudinal structure.
1. Introduction
The Long-Term Pavement Performance (LTPP) program is a study of the behaviour of pavement test sections located on in-service roadways constructed using highway agency specifications and contractors, and subjected to real-life traffic loading throughout the United States and Canada [1].
2. Literature review
Thus far, several studies have been conducted using the LTPP SPS-5 data.
3. Data
The data used in this study are collected in SPS-5 project as part of the Long-term Pavement Performance (LTPP) program. The SPS-5 experiment evaluates the effectiveness of typical asphalt overlays on existing asphalt pavements that are commonly used by highway agencies.
4. Methodology
To account for the clustered longitudinal data structure of the SPS-5 IRI data, a multilevel model (MLM) is developed in this study. The clustered longitudinal data structure can violate the independence assumption required by popular statistical techniques such as ordinary lest-squares (OLS) multiple regression and ANOVA [16].
6. Conclusions
This study examined the effect of overlay thickness, overlay material, and pre-overlay treatment on evolution of asphalt overlay roughness in LTPP SPS-5 experiment. Roughness data were measured and collected repeatedly on test sections nested within experimental sites.
How are inlays and onlays preformed?
Both inlays and onlays are pre-formed in a lab before being bonded to the damaged or decayed tooth. The difference of use depends on the amount of tooth structure that has been lost to wear or decay. Your dentist will help you decide which is most appropriate for you.
Why do we need inlays and onlays?
Dental inlays and onlays are a dental procedure that is used to restore a decayed or damaged tooth to its original condition and can actually strengthen it. They are a more conservative approach than a dental crown because they don’t involve the removal of healthy tooth structure. For this reason, inlays and onlays are considered ...
What is temporary restoration?
A temporary restoration is placed on the tooth until the inlay or onlay comes back from the lab. Patients should consider looking for a dentist who can provide a single visit restoration as the time it takes a dental lab to fabricate the inlay or onlay can vary.
What is an inlay in dental?
An inlay fits within the grooves that are within the cusps of your teeth. An onlay, the larger of the two, fits within the grooves but wraps up and over the cusps covering more of the tooth’s surface. An onlay is used when the damage is more extensive and the restoration covers the entire chewing surface including one or more tooth cusps.
Why do you put an inlay on a tooth?
The inlay or onlay will be placed to ensure a correct fit before it is bonded to the tooth. If the fit doesn’t interfere with the patient’s bite, it is permanently attached to the tooth using special cement or bonding then polished for appearance.
How many visits does it take to do an inlay?
The procedure to place an inlay or onlay is basically the same and both require two dental visits unless your dentist has an in-office milling unit (See CAD/CAM Dentistry ).
Is an inlay a good dental treatment?
For this reason, inlays and onlays are considered a minimally invasive cosmetic dentistry treatment and for many dentists and patients is a much better choice. A crown, although not a bad procedure, involves the removal of more healthy tooth structure than needed and can increase the risk of tooth fracture and the need for a root canal treatment.
