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Technical Notes 14A
Brick Floors and Pavements, Part II - Materials and Installation
January 1993

Abstract: This Technical Notes describes the materials and installation methods used to construct brick paving assemblies. Materials covered include brick, setting bed materials, base materials and membranes. Installation procedures for flexible, semi-rigid and rigid base paving assemblies are described. Maintenance issues are also discussed.

Key Words: brick, flexible pavements, installation, maintenance, mortared paving, mortarless paving, paving, rigid pavements.

INTRODUCTION

The longevity of brick paving applications has been proven through many years of successful in-service performance. This performance is the result of proper design, proper selection of materials and good workmanship. Even though brick is the uppermost surface, it is the base which requires the closest scrutiny and adequate preparation for proper performance of the entire system. However, all paving materials and layers should be analyzed and constructed properly.

This Technical Notes deals with the proper selection of materials and their installation. Guidance is also provided for the maintenance of brick paving assemblies. Other Technical Notes in this series address design, detailing and special brick paving assemblies including floors.

SELECTION OF MATERIALS

Brick

Paving brick selection is usually based on its weather resistance, abrasion resistance, and appearance relating to bond patterns, size and tolerances. Brick used in paving applications should conform to ASTM C 902 Specification for Pedestrian and Light Traffic Paving Brick or the proposed ASTM Specification for Heavy Vehicular Paving Brick (As of the date of this publication, this standard had not completed the ASTM consensus process.)

Durability. For exterior pavements, resistance to deterioration due to freezing in the presence of moisture is of the utmost importance. Repeated freezing and thawing of moisture within a paving assembly can increase the rate of deterioration and may result in cracking or spalling of the units. The overall durability of the pavement under these conditions is dependent upon the quality of materials and the drainage efficiency of the pavement. See Technical Notes 14 Revised for information on drainage.

Three weathering classes found in ASTM C 902 are SX, MX and NX. Class SX pavers are intended for use where the brick may be frozen while saturated with water. Class MX pavers are intended for exterior use where freezing conditions are not present. Finally, Class NX pavers are acceptable for interior use where protected from freezing when wet. The durability of a paving brick is measured using combinations of its compressive strength, 24 hr cold water absorption and saturation coefficient. Table 1 shows the physical property requirements found in ASTM C 902 for durability in each class.

Alternates to these requirements are also found in ASTM C 902. The alternates include a maximum water absorption, a 50 cycle freezing and thawing test, a sulfate soundness test, and a performance alternate. The maximum saturation coefficient in Table 1 is not required when the average 24 hr cold water absorption is less than 6 percent. The maximum saturation coefficient and maximum cold water absorption in Table 1 are not required when the brick passes the 50 cycle freezing and thawing test. The sulfate soundness test is used as an alternate test in place of the requirements of Table 1. The performance alternate allows the manufacturer to furnish data showing that the units perform well in a similar application of similar exposure and traffic. The performance alternate must be found acceptable by the specifier. Alternates are provided in ASTM C 902 because the performance of units is not easily determined by limiting physical properties alone. The use of alternates does not signify that the brick are of a lower quality, but allows the use of units which are known to have good performance.

  

Abrasion Resistance. Paving brick are exposed to the continual abrasive effect of pedestrian and vehicular traffic. Of these two types of traffic, pedestrian traffic can cause the most wear of the pavement surface. The impact force of high-heeled shoes causes the highest degree of abrasion. Tires, without studs, do not have such a drastic effect, although brick streets will polish over time with repeated tire traffic.

Abrasion resistance is a measure of the resistance of paving brick to the wearing action due to traffic. ASTM C 902 lists two ways in which the abrasion resistance of brick pavers can be determined: 1) an abrasion index calculated by dividing the 24 hr cold water absorption by the compressive strength (units of psi) and then multiplying by 100, or 2) by the volume abrasion loss in accordance with ASTM C 418 Test Method for Abrasion Resistance of Concrete by Sandblasting. The abrasion requirements for pavers by traffic type are shown in Table 2.

 

Slip and Skid Resistance. The slip resistance of a paving surface is related to pedestrian traffic, while skid resistance is related to vehicular traffic. Slip resistance and skid resistance are measures of the slipperiness of a paving surface. Slip resistance and skid resistance are adversely affected by the accumulation of water on the pavement surface. Over time, the skid resistance of all paving surfaces decreases because of the polishing effect of traffic. The skid resistance of most brick is initially very high and decreases while in use, approaching an equilibrium condition within one year after placement. Since both slip and skid resistance rely on the microtexture of the paving brick, a brick with a rougher texture such as a wire cut paver will provide a higher slip and skid resistance.

There are no requirements for testing slip and skid resistance in ASTM C 902, although there are methods for testing skid resistance in the proposed ASTM Specification for Heavy Vehicular Paving Brick. The latter specification references ASTM E 303 Method for Measuring Surface Frictional Properties using the British Pendulum Tester (BPT). Skid resistance values of new brick pavers vary between 51 and 87 which fall within the range of concrete and asphalt pavements. [4]

Dimensions. Brick pavers are available in a wide range of sizes. The most commonly available sizes of pavers are listed in Table 3. Some pavers used in mortarless applications may have a small chamfer not exceeding 3/16 in. (5 mm) in depth or width, or rounded edges with a radius less than 3/16 in. (5 mm). Chamfers provide a better path for surface drainage along the pavement surface, better slip and skid resistance and reduce the amount of chippage along the top edges of the brick during installation and use. The chamfer dimension is subtracted from the specified height when determining the thickness of the pavement surface layer for design. Pavers used in mortarless applications, especially heavy vehicular pavements, may be made with lugs or spacers. These lugs, usually 1/8 in. (3 mm) in size, space the pavers apart and provide a controlled gap for jointing sand. Lugs also keep the paver edges from touching to reduce the amount of chippage during compaction and use. Lugs should be included when measuring the specified dimensions and when laying out a paving pattern.

 

The dimensional tolerances for pavers from ASTM C 902 are listed in Table 4. Dimensional tolerances are more critical in mortarless brick paving applications than in mortared brick paving applications since thin sand joints cannot accommodate paver dimensional variation as easily as thicker mortar joints. Brick with larger dimensional variation will shift the alignment of the pattern, making installation difficult in mortarless herringbone and basketweave applications.

 

Salvaged Brick. The use of salvaged brick is generally not recommended for paving applications. This is obviously true for used building or facing brick. The durability of brick depends upon the properties of the units. Generally speaking, salvaged brick will not be uniformly durable when used in a pavement which is exposed to weathering. Some older "vitrified brick pavers" are extremely durable, but are often difficult to distinguish from poor pavers. Only a paver's past performance can be used for comparison.

Setting Bed Materials

The setting bed, placed between the base and the paving surface, functions as a leveling course to help refine the finished grade due to slight irregularities in the base or the units. Setting bed materials may be sand, building felt, asphalt or mortar.

Sand. Sand used as the setting bed should be a washed, well-graded angular sand with a maximum particle size of about 3/16 in. (4.8 mm). Sand should conform to either ASTM C 33 Specification for Concrete Aggregates or ASTM C 144 Specification for Aggregate for Masonry Mortar. In setting beds thinner than 1 in. (25 mm), smaller sand particles such as sands conforming to ASTM C 144 should be used. In setting beds thicker than 1 in. (25 mm) and all vehicular applications, sand conforming to ASTM C 33 should be used. Naturally occurring silica sand should be used in vehicular pavements.

The sand should be free of salts and other deleterious materials to avoid efflorescence or staining. The use of dry sand-cement mixtures should be avoided. Although cement may tend to keep the sand in place initially, the mixture will likely break up in a short time due to flexing of the paving system and weathering. In addition, use of a sand-cement mixture makes removal and reuse of the paving units more difficult.

Materials not suitable for use as the setting bed include sands with clay or dust in excess of that permitted in ASTM C 33 or C 144. Also, fine limestone screenings must not be used, since this material is normally too soft and may cause staining.

Building Felt. In residential pedestrian applications, brick may be placed directly on an asphalt or concrete base. In these applications, building felt may serve as a cushion between the brick pavers and the base, and compensate for minor dimensional variations in the base or brick. Generally, two layers of No. 15 building felt or one layer of No. 30 building felt is appropriate. Building felt should conform to ASTM D 226 or D 227.

Asphalt. Asphalt setting beds composed of aggregate and asphaltic cement may be used. Proportions of these materials are generally determined by specialty contractors or the asphalt plant and are beyond the scope of this Technical Notes; however, an asphalt setting bed generally consists of 7% asphalt and 93% sand. This mix is typically prepared and heated at an asphalt plant before being delivered to the job. A tack coat of neoprene modified asphalt should be placed on top of the asphalt setting bed to help adhere the pavers to the setting bed.

Mortar. Mortar setting beds are used in mortared brick paving applications. Mortar should conform to the proportion specifications of ASTM C 270 Specification for Mortar for Unit Masonry or ANSI A118.4 Specification for Latex-Portland Cement Mortar when a latex additive is used.

For exterior mortared brick paving on grade, Type M mortar is preferred. Type M mortar consists of 1 part portland cement, 1/4 part hydrated lime and 3 3/4 parts sand; or 1 part Type M masonry cement and 3 parts sand. Type S mortar may be used for exterior applications when the pavement is not in contact with the earth, such as suspended diaphragms or in interior applications. Type S mortar consists of 1 part portland cement, 1/2 part hydrated lime and 4 1/2 parts sand; or 1 part Type S masonry cement and 3 parts sand. Portland cement should conform to ASTM C 150, Types I, II or III. Masonry cement should conform to ASTM C 91, Type M or S. Hydrated lime should conform to ASTM C 207, Type S, and sand should conform to ASTM C 144. The thickness of the mortar setting bed may vary from 3/8 in. to 1 in. (10 mm to 25 mm).

Bond coats may be used between the concrete slab and mortar setting bed. Bond coats consist of portland cement mixed to a creamy consistency with water or a latex additive. The bond coat is used to create improved bond between the concrete slab and the mortar setting bed. It is installed as the setting bed and pavers are laid, and should not exceed 1/16 in. (2 mm).

Latex-portland cement mortars improve bond strength, reduce water absorption and provide greater durability than conventional mortars. These mortars should be used in applications such as heavy vehicular traffic pavements or pavements where proper drainage is not possible. Latex-portland cement mortars are also useful in mortared brick paving over a suspended diaphragm and are typically used in thin-set mortar applications. Latex additives are water emulsions which are added to and may replace all or part of the mixing water. It is advisable to check latex-modified mortar and brick compatibility with respect to bond strength by preconstruction testing.

Jointing Materials

Materials used between brick pavers may be mortar or sand. Mortared brick paving uses mortar between the pavers. This mortar should be the same as the mortar used for the setting bed. In mortarless brick paving, the sand which is placed between the pavers should conform to ASTM C 144 (mason's sand). However, the maximum particle size should not be larger than the joint size. Typically, 1/8 in. (3 mm) joints are used in mortarless brick paving. The sand should be clean and washed with no deleterious materials. When mortarless brick paving is used on slopes or in areas where jointing sand may be washed out, a portland cement-sand mixture can be used. This mixture should be used with caution as it often stains pavers during installation and makes their reuse difficult. If a sand-cement mixture is necessary, it should consist of 1 part portland cement and 6 parts sand.

Base and Subbase Materials

Base and subbase materials consist of crushed aggregate, gravel, sand, asphalt or concrete. Suspended diaphragms are usually made of concrete, steel or wood. Asphalt and concrete bases often require an aggregate subbase. Some flexible bases may require a subbase because of heavy traffic loads or poor subgrade conditions.

Aggregate Bases and Subbases. Crushed, quarry-processed aggregate is often used as a base material because of its availability, ease of use in construction and good performance. Naturally-occurring gravel may also be used if it meets proper gradation requirements. The maximum size of aggregate used in construction depends upon the size of the project and the size of the compaction equipment being used. Proper gradation of materials is required to achieve adequate compaction. Gradation should conform to ASTM D 2940 for heavy traffic applications, while smaller projects can simply require aggregate graded down from 3/4 in. (19 mm) in size. Aggregates are produced from different raw materials and are called different names in different parts of the country. Therefore, aggregate should be specified by gradation rather than by name.

Either dense graded or open graded aggregate may be used, although dense graded crushed aggregate develops a stronger, more impervious base. Open graded aggregate is often used in areas of poor drainage or in areas subjected to frost heave. If an open graded aggregate base is used beneath a sand setting bed, a geotextile must be used to prevent sand from filtering into the base.

In residential pedestrian applications, sand bases can be used when the subgrade is compacted or bearing on undisturbed earth, and in areas where frost heave is not a consideration. Sand should conform to ASTM C 33 (concrete sand) and be clean and free of deleterious materials. Salts in the sand will often wick up through the brick, showing efflorescence on the surface.

Asphalt Bases. New or existing asphalt bases may be used to support brick paving. Major defects such as cracks or holes in existing asphalt bases should be repaired prior to installation of brick. A membrane can be placed over an existing asphalt base to strengthen the pavement and prevent the sand setting bed from sifting through cracks in the asphalt. The specification of asphalt for bases is beyond the scope of this Technical Notes, but the asphalt should conform to ASTM D 3515 (hot-mixed asphalt), ASTM D 4215 (cold-mixed asphalt) or local codes.

Concrete Bases. New and existing concrete bases may be used for brick paving. New concrete should be installed following recommended concrete practices. Where a mortar setting bed is bonded to a new concrete slab, a rough textured finish should be used such as that produced by a screed or wood float. Concrete bases should be properly cured before the brick pavers are installed. If brick paving is placed over existing concrete, the concrete should be sound, with major cracks properly repaired. A geotextile can be used to bridge cracks when using a sand setting bed to prevent sand from sifting into the cracks. The specification of concrete for bases is beyond the scope of this Technical Notes, but should conform to local codes.

Membranes

Membranes are used in brick paving applications to separate layers in a paving system, accommodate differential movement or serve as a waterproofing element. Membrane materials include geotextiles, sheet membranes and liquid membranes.

Geotextiles or geosynthetics are used to separate pavement layers while still allowing drainage. They are composed of various types of fibers that are either woven or nonwoven. Thickness, permeability, elongation, grab strength, burst pressure and durability are properties of geotextiles which should be examined for their suitability in brick paving applications. The specification of geotextiles is beyond the scope of this Technical Notes. Geotextile manufacturers should be consulted on the suitability of their product in a particular brick paving application.

Sheet membranes are often used as bond breaks or waterproofing membranes. Materials such as building felt, PVC, polyethylene or other proprietary membranes can be used in brick paving applications. Felt should conform to ASTM D 226 or D 227. Strength and thickness of these materials should be such that they will resist punctures.

Liquid-applied membranes are often used to waterproof decks and may be used as bond breaks. When used to waterproof, liquid-applied membranes should be self-adhered to the base to minimize migration of water caused by leaks. Application and thickness of the liquid membranes should follow the manufacturer's recommendations.

INSTALLATION AND WORKMANSHIP

One factor which has a great impact on the performance of brick pavements is workmanship. Proper preparation and compaction of the base is absolutely critical. There are numerous ways to install brick pavements which vary by region. The recommendations in this Technical Notes are based on experience and provide a minimum level of workmanship necessary for satisfactory performance.

Subgrade Preparation

One element common to all paving assemblies is the soil or subgrade. In preparation for the base or subbase, the subgrade should be excavated to the proper elevation, deleterious materials removed, and the subgrade compacted. If subsurface drainage is required, drain pipes should be installed and be properly backfilled. The entire subgrade should be compacted to 90-95% maximum density.

Flexible Base Systems

Only mortarless brick paving should be placed over flexible bases. Generally, flexible bases are the most economical type of base to install. Proper construction of the subbase, sand setting bed and brick pavers is necessary to ensure good performance.

Subbase and Base Preparation. The subbase and base materials should be spread and compacted in layers. The thickness of these layers must be consistent with the capabilities of the compaction equipment. Heavy compaction equipment such as vibratory rollers may be necessary when constructing a street with crushed stone, whereas a plate vibrator may be used when constructing a sand base for a residential patio. Each material should be placed and compacted in layers no greater than 4 in. (100 mm). It is essential that the intended surface profile of the pavement is formed by the base so the pavers can be placed on a uniform thickness of bedding sand.

If a geotextile is used, it should be placed after compaction of the subgrade or base. The geotextile should be placed smooth and be overlapped a minimum of 12 in. (300 mm) at its ends. The geotextile should be lapped further in conditions such as poor soils. The geotextile should be placed so that the material entirely covers the base and extends up the side of the excavated area to contain the setting bed material. Construction equipment should be kept off of the geotextile. Check the geotextile manufacturer's literature for further installation recommendations.

Edge restraints should be placed before base installation if the restraint is anchored below the base. The edge restraint should be installed after base compaction if it is intended to be anchored into the base. In the latter case, the base should extend at least 6 in. (150 mm) past the end of brick paving above.

Setting Bed Preparation. The setting bed material should be spread over the base in a uniform thickness. A screed board is often used to spread the sand. The setting bed is not meant to and should not be used to fill in low spots nor its thickness adjusted to bring the pavement to the correct grade. Any changes in thickness or undulations in the sand will reflect on the pavement surface. To prevent disturbance of the sand it should not be spread too far in front of the laying face of the pavers. Prepared setting bed materials left overnight should be properly protected from disturbance and moisture. The moisture content of the sand during installation should be as uniform as possible, with the material moist but not saturated. Stockpiled sand should be kept covered to prevent contamination.

Paver Installation. Pavers should be laid in the desired bond pattern with a 1/16 to 1/8 in. (2 to 3 mm) average joint width. The term "handtight" is a misnomer since sand between the pavers is desired. The joint width should not exceed 1/4 in. (6 mm).

String lines or chalk lines may be used to keep the pattern aligned. Whole pavers should be laid first, followed by pavers cut to size. All pavers should be cut with a masonry saw to produce an accurate, clean, straight cut. A trial area may be laid out in advance of work to determine paver positions and minimize the amount of cutting required.

In pedestrian paving applications, jointing sand may be swept into the joints. In some pedestrian and all vehicular paving applications, the brick should be vibrated into place using a mechanical plate vibrator/compactor. Compaction of the brick forms a more stable surface and promotes interlock between the sand and pavers. If a vibrator is used, the first pass of the vibrator should be prior to the spreading of jointing sand to force bedding sand into the joints from below. On subsequent vibrator passes, jointing sand is spread across the surface before compaction. Several passes of the vibrator may be necessary to fill the joints. Compaction should not occur within 3 ft (0.9 m) of any unrestrained edge.

Semi-Rigid Base System

Only mortarless brick paving should be placed over a semi-rigid asphalt base. Typically, an asphalt base is supported by an aggregate subbase. Each material layer is compacted as placed. An asphalt or bituminous setting bed is placed over the base. Usually delivered hot from the plant, the asphalt setting bed is rolled to a 3/4 in. (19 mm) depth. A tack coat of 2% neoprene-modified asphalt adhesive should be applied by a mop, squeegee or trowel on top of the asphalt setting bed. This tack coat should be very thin, not exceeding 1/16 in. (2 mm), to avoid pumping of the material between the pavers and onto the surface when hot. When the tack coat is dry to the touch, paving units may be laid in the desired bond pattern. After brick placement, sand should be swept into the joints.

Rigid Base Systems

Both mortarless and mortared brick paving systems may be laid over a rigid concrete base. Concrete bases may or may not be laid over an aggregate subbase depending upon the application and traffic. Typically, the concrete base should cure a minimum of seven days before installation of the setting bed and pavers.

In mortarless applications, a sand or asphalt setting bed is laid directly on top of the concrete base. A 1/2 in. (13 mm) sand setting bed or 3/4 in. (19 mm) asphalt setting bed is used. A thin tack coat is applied to the asphalt setting bed. Membranes can be laid directly on the concrete base, but only after the base has cured properly. The pavers are laid and jointing sand is swept into the joints.

When pavers are installed with mortar, standard bricklaying or tile setting procedures should be followed. The preferred method of mortar placement is with a trowel. The concrete base should be clean and slightly dampened, but be surface dry immediately prior to placing the mortar setting bed. The setting bed is laid in the desired thickness, no more than 2 ft (0.6 m) ahead of the laying of the paving units. Brick pavers should be buttered with mortar on the bottom and edges and shoved into the mortar setting bed. The joints between the units should be completely filled to minimize moisture penetration. Joints should be tooled with a concave jointer when the mortar becomes thumbprint hard.

When installing thin pavers, a thin mortar bed is used. As with full pavers, the concrete base is cleaned and dampened. However, a bond coat is applied to the concrete base prior to installation of the setting bed. The mortar setting bed and thin pavers are immediately installed on top of the bond coat.

If care is exercised during mortar installation, cleaning can be avoided or kept to a minimum. Burlap bags rubbed over the surface or wet sand swept over the surface may remove some mortar droppings which are still soft. If cleaning is necessary, use procedures and cleaning solutions recommended in Technical Notes 20 Revised. Avoid the use of acid solutions when possible.

An alternate method of installation of full or thin pavers involves placing pavers on a mortar setting bed and leaving a space the size of a mortar joint between the units for a grout mixture. A grout mixture with proportions of cement, lime and sand the same as the appropriate mortar but with greater flow is used. The grout is poured, injected or squeegeed into the joints after the pavers have set in the mortar. The joints are tooled to a concave finish when the grout is thumbprint hard. When grout is placed in the joints in this manner, special care must be taken to protect the units from grout stains. Pavers may have their top surface coated with paraffin or wax before they are laid. Failure to coat the pavers will result in stains on pavers that are difficult to remove. Coated pavers may be special ordered from the brick manufacturer, or the coating may be applied at the jobsite. The paraffin or wax should have a melting point between 150 and 170°F (66 and 77°C). Experience has shown that materials with lower melting points are often affected by hot sunlight, while those with higher melting points are difficult to remove. While applying the coating, care must be taken to prevent the edges or joint surfaces of the pavers from becoming coated since the edges must be clean for proper bond. The pavement should be steam cleaned soon after the mortar in the joints has cured.

Pavement Tolerances

The maximum variation from plane of the pavement surface should be ± 3/8 in. in 10 ft (± 10 mm in 300 mm). The edges of any two adjacent pavers should not differ by more than 1/16 in. (2 mm) in height for mortarless brick paving or 1/8 in. (3 mm) for mortared brick paving. Pavers adjacent to drainage inlets and channels should not be lower than the top of the drain and not be more than 3/16 in. (5 mm) above it.

MAINTENANCE

Although brick paving surfaces are very durable, some routine maintenance may be necessary.

Snow Removal

Snow removal from brick pavements should not present any particular problem. It can be removed by plowing, blowing or brushing away the snow. When using plows or shovels there are precautionary measures that can be taken to preserve the surface character of the brick. Metal blades should be rubber tipped or mounted on small rollers. The blade edge should be adjusted to a clearance height suitable for the pavement surface. Avoid the use of any chemicals containing rock salt to aid in melting ice. Use of these materials may cause efflorescence. A product called urea is used to melt ice at many airports without causing efflorescence. Otherwise, remove snow before it can be compacted or turn to ice. To render icy surfaces passable, use clean sand on the icy areas.

Efflorescence

Many times efflorescence, a white powdery substance produced by soluble salts, is unavoidable on a paving surface. Deicers used on adjacent areas may be deposited onto the brick pavement, soluble salts may be present within paving system components or salts may migrate from adjacent soils. Therefore, proper drainage and maintenance are especially critical to reduce the amount of efflorescence. If efflorescence does appear on the paving surface, natural weathering or traffic will usually eliminate it. See Technical Notes 23 Series for more information of efflorescence.

Coatings

Coatings or sealers are often desirable on interior brick floors to facilitate cleaning. Coatings on exterior brick pavements are not recommended unless the coating has been proven to perform on exterior brick pavements. Coatings generally have two purposes, to lock loose sand in the joints for mortarless paving and to prevent staining and facilitate cleaning. Coatings used to prevent jointing sand erosion should be applied to the joints only. All coatings used in exterior applications must have a high vapor transmission rate and not adversely affect the slip resistance of the pavement. Before any coating is applied, the pavement surface should be fully dry and clean. The choice of any coating should be based on its intended result.

Repairs

Repointing of mortar joints may be necessary due to deterioration of the mortar. Procedures given in Technical Notes 7F should be followed. A stronger repointing mix is recommended for paving applications than for wall applications. Type S mortar is usually sufficient to provide good durability as a repointing mortar.

At some time, a brick pavement or utilities under the pavement may have to be repaired. In mortared brick paving, units and base materials that are removed should be discarded and not used again. The returned fill and subbase should be well compacted and the new base poured in place. The mortar and pavers should be replaced using techniques similar to those described for new construction.

In making repairs on flexible brick pavements, the paving brick may be reused. A single unit is removed initially, preferably with a purpose-made tool to prevent damage of the paver. Adjacent pavers may subsequently be removed and stacked nearby to be used again if not damaged. Temporary edge restraints should be placed at the perimeter of the exposed area to minimize creeping of the pavement. At all times, vehicular traffic should be kept at least 6 ft (2 m) away from the work edges. Proper compaction of the new or returned fill material is very important. Fill material should be brought up to the proper level and compacted. If the area is too small to permit proper compaction, self-stabilized materials such as concrete should be used. One to two ft (0.3 to 0.6 m) of pavers around the perimeter of the excavated area should be removed so that accurate levels can be established from undisturbed work. The sand setting bed should be screeded and compacted. A thin layer of sand should be screeded on top of the setting bed to bring the setting bed to the proper level. The pavers are then re-laid in the correct bond pattern. If creep of the pavement has occurred during repairs, some units may have to be saw cut to fit, although temporary edge restraints should avoid excessive creep. Jointing sand should be spread over the top of the pavers and the system vibrated to the finished level with a plate compactor if appropriate.

SUMMARY

This Technical Notes describes the proper selection of materials and installation methods for brick paving assemblies. The importance of proper installation cannot be stressed enough for pavement performance and longevity. Information on maintenance of brick paving assemblies is also provided.

The information and suggestions contained in this Technical Notes are based on the available data and the experience of the engineering staff of the Brick Institute of America. The information contained herein must be used in conjunction with good technical judgment and a basic understanding of the properties of brick masonry. Final decisions on the use of the information contained in this Technical Notes are not within the purview of the Brick Institute of America and must rest with the project architect, engineer and owner.

REFERENCES