Pavement patching

The Asphalt Institute (Asphalt Institute MS-17 3rd Edition) defines maintenance as routine work to keep a pavement as close to its desired level of serviceability as possible. This includes the preservation of existing pavement surfaces, resurfacing of less than the nominal overlay thickness, resurfacing of a short length of pavement, patching and repair of minor failures and the undersealing of concrete slabs. 

Quick setting silico-phosphate cements have been considered for use as pavement patching material. These are cement compositions which have a sufficiently high and rapidly developed early strength to support normal highway loads within one hour after application. 

Check the site for evidence of substructures such as manhole covers, valve box covers, meter boxes, electrical transformers, conduits or drop lines from utility poles, and pavement patches. HDD may be a suitable method in areas where the substracture density is relatively high... 

Master, n. (medical) plaster pavement, paving patch, -kafer, m. Spanish fiy, blister beetle. 

The performance of a pavement is the history of its level of service over its lifetime to the traveling public. The pavement that remains smooth and uncracked with few patches after 10 years is generally thought to perform well. Consistent measures of its present level of service are in standard use and are considered in some detail later. 

The overall structural adequacy of pavements is given in probabilistic terms of the present serviceability index developed from the AASHTO road test (17). This index, which is a measure of the momentary ability of a pavement to serve traffic, is based on such factors as rut depth, slope variance, cracking, and patching of the pavement. The relationship between serviceability index and these pavement distress modes is given by the AASHTO road test equation (16) ... 

MAJOR PRODUCT APPLICATIONS filtration, ceramics, foams, floor tiles, shoe soles, paints, food, building products, welding electrodes, gaskets, stucco, EIFS, asbestos alternative, sealants, roof coatings, athletic surface coatings, crack fillers and sealers, brake pads, clutches, pavement, artificial leather, electrical components, automotive components, household appliances, mastics, putties, patching compounds, grouts... 

CEN EN 13036-1.2010. Road and airfield surface characteristics - Test methods - Part 1 Measurement of pavement macrotexture depth using a volumetric patch technique. Brussels CEN. 

The above constitutes a totally different design concept, somewhat more practical, provided the user is not interested in whether the pavement has been cracked or deformed, or whether it has one or two patches. He is interested in whether or not the pavement provides some tolerable serviceability level. 

Full-depth patching in brief The area that is to be repaired (patch area) should be extended approximately 500 mm inside the non-stressed area. The outline of the patch is cut by a pavement saw cutter. All materials are carefully removed, or excavated, down to the required depth in the case of localised alligator cracking area, most probably down to part of the subgrade material. All cut and excavated faces should be straight and vertical. 

Extra care should always be taken for the surface of the patch to be at the same level (grade) as the surrounding pavement. 

Woodside A.R., W.D.H. Woodward and A. Graham, 2011. The use of glass fibre addition to reinforce a road patch. Proceedings, 5th International Conference Bituminous Mixtures and Pavements. Thessaloniki, Greece AUTh. 

The subjectivity of rating the pavement condition by users in terms of PSR has led to the development of the present serviceability index (PSI). The same sections of the AASHTO study were also surveyed at the same time and physical measurements (slope variance in wheel paths, cracking, area of patching and rut depth) were carried out (AASHTO 1962). The PSR estimated from objective physical measurements was termed PSI. The equations derived to determine PSR in an objective way in terms of PSI were as follows ... 

The pavement surface texture, that is, surface macro-texture, can be determined in terms of MTD, using a volumetric technique (sand patch method), or in terms of MPD, using laser sensor devices. 

Figure 16.20 Explanation of texture depth determination and measuring device. (Adapted from CEN EN 13036-1, Road and Airfield Surface Characteristics - Test Methods - Part I Measurement of Pavement Surface Macro-Texture Depth Using a Volumetric Patch Technique. Brussels CEN, 2010. With permission [ CEN] and ASTM E 965, Standard Test Method for Measuring Pavement Macro-Texture Depth Using a Volumetric Technique. West Conshohocken, PA ASTM International, 2006.)...

The blending of GRT with asphalt was begun in the 1960s by McDonald, who developed and patented a patching material consisted of 25 wt% scrap and asphalt blended at 375°F for 20 minutes [193]. MacDonald continued his work by expanding it to actual road pavement test sections as a seal coat, and in 1968, Sahmaro Petroleum and Asphalt conducted application of a blend of GRT and asphalt as a binder for hot premix. The hot premix is a mixture of stone aggregate, sand, and the tire-asphalt binder all premixed in a batch- or drum-type mixer. This material is then applied as a carpet on top of the road... 

Why did the accident happen Did Robert W. suddenly get ill and lose control Was there an icy patch on the pavement Both were possibilities. However, only family and close Mends had another theory for the accident Robert W. had terminal cancer and recently was depressed. He may have committed suicide. 

Applications of polymer mortars and polymer concretes include patching of Portland cement concrete, floor and pavement overlays, anti-corrosive linings, precast products, vaults, panels [8,11]. These indicate that there is no single polymer concrete that performs all of these tasks. Application and performance of polymer concrete depend on the binder used and the aggregate. Copolymerisation techniques allow the production of a wide range of binders with varying properties [11]. 

PPCC applications include deck coverings, floors, pavements, precast units, anti-corrosive linings, adhesives, patching or repairing Portland cement concretes [11, 17]. 

If the disintegration is shallow, it may be possible to use a latex-fortified or an epoxy mortar to patch the area. The mixtures of latex and cement and sand described under Repairing Surfaces of Pavement and Slabs may be used. An epoxy mortar may also be used, but it may not blend readily with the surrounding concrete in color or appearance. 

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