Mortar Ancient Masonry History of Mortar Mud parging in Egypt – 4000 B.C. Alabaster with bitumen – 3000 B.C. Sand and gypsum mortar.
Download ReportTranscript Mortar Ancient Masonry History of Mortar Mud parging in Egypt – 4000 B.C. Alabaster with bitumen – 3000 B.C. Sand and gypsum mortar.
Mortar Ancient Masonry 2 History of Mortar Mud parging in Egypt – 4000 B.C. Alabaster with bitumen – 3000 B.C. Sand and gypsum mortar – 2500 B.C. Sand lime mortar – 500 B.C. 1:3 lime:sand ratio established – 10 B.C. 3 Early American Masonry 4 History of Mortar Sand lime mortar used in U.S. – 1700s Portland cement invented – 1824 5 Modern Masonry 6 History of Mortar Portland cement lime mortar – Early 1900s Masonry cement mortar – 1930s Mortar cement mortar – 1990s 7 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 8 ASTM’s Related to Mortar Standard Specifications C91 Standard Specification for Masonry Cement C144 Standard Specification for Aggregate for Masonry Mortar C270 Standard Specification for Mortar Unit Masonry C887 Standard Specification for Packaged, Dry, Combined Materials for Surface Bonding Mortar C1142 Standard Specification for Extended Life Mortar for Unit Masonry C1329 Standard Specification for Mortar Cement C1384 Standard Specification for Modifiers for Masonry Mortars 9 not in binder 10 not in binder 11 not in binder 12 not in binder 13 not in binder 14 not in binder 15 not in binder 16 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 17 C270 – 03b Standard Specification for Mortar for Unit Masonry1 1. Scope 1.1 This specification covers mortars for use in the construction of non-reinforced and reinforced unit masonry structures. Four types of mortar are covered in each of two alternative specifications: (1) proportion specifications and (2) property specifications. 18 Mortar Types 19 C270 – 03b Standard Specification for Mortar for Unit Masonry1 1.3 When neither proportion or property specifications are specified, the proportion specifications shall govern, unless data are presented to and accepted by the specifier to show that mortar meets the requirements of the property specifications. 20 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 21 C270 – 03b Standard Specification for Mortar for Unit Masonry1 2. Referenced Documents 2.1 C5 ASTM Standards Specification for Quicklime for Structural Purposes C91 Specification for Masonry Cement C109 Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or Cube Specimens) C110 Test Methods for Physical Testing of Quicklime, Hydrated Lime, and Limestone C128 Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine Aggregates C144 Specification for Aggregate for Masonry Mortar 22 not in binder C144 – 02 Standard Specification for Mortar for Unit Masonry1 4.4 When an aggregate fails the gradation limits specified in 4.1 and 4.2, it may be used provided the mortar can be prepared to comply with the aggregate ratio, water retention, and compressive strength requirements of the property specifications of Specification C 270. 23 C270 – 03b Standard Specification for Mortar for Unit Masonry1 C150 C188 C207 C305 C511 C595 C780 Specification for Portland Cement Test Method for Density of Hydraulic Cement Specification for Hydrated Lime for Masonry Purposes Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency Specification for Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes Specification for Blended Hydraulic Cements Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and 24 Reinforced Unit Masonry not in binder C780 – 02 Standard Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry1 1.4 The test results obtained under this test method are not required to meet the minimum compressive values in accordance with the property specifications in Specification C 270. 25 not in binder C780 – 02 Standard Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry1 26 C270 – 03b Standard Specification for Mortar for Unit Masonry1 C952 C1072 C979 C1157 C1180 C1324 C1329 C1357 Test Method for Bond Strength of Mortar to Masonry Units Test Method for Measurement of Masonry Flexural Bond Strength Specification for Pigments for Integrally Colored Concrete Performance Specification for Hydraulic Cement Terminology of Mortar and Grout for Unit Masonry Test Method for Examination and Analysis of Hardened Mortar Specification for Mortar Cement Test Methods for Evaluating Masonry Bond 27 Strength not in binder C1072 – 00a Standard Test Method for Measurement of Masonry Flexural Bond Strength1 28 not in binder C1148 – 92a (Reapproved 2002) Standard Test Method for Measuring the Drying Shrinkage of Masonry Mortar1 29 not referenced not in binder C1180 – 02 Standard Terminology for Mortar and Grout for Unit Masonry1 mortar, n—a mixture consisting of cementitious materials, fine aggregate, water, and with or without admixtures, that is used to construct unit masonry assemblies. 30 C270 – 03b Standard Specification for Mortar for Unit Masonry1 2.2 Masonry Industry Council: Hot and Cold Weather Masonry Construction Manual, January 1999 31 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 32 C270 – 03b Standard Specification for Mortar for Unit Masonry1 3. Specification Limitations 3.1 Specification C 270 is not a specification to determine mortar strengths through field testing. 33 C270 – 03b Standard Specification for Mortar for Unit Masonry1 3.3 The compressive strength values resulting from field tested mortars do not represent the compressive strength of mortar as tested in the laboratory nor that of the mortar in the wall. Physical properties of field sampled mortar shall not be used to determine compliance to this specification and are not intended as criteria to determine the acceptance or rejection of the mortar. 34 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 35 C270 – 03b Standard Specification for Mortar for Unit Masonry1 4. Materials 4.1 Material used as ingredients in the mortar shall conform to the requirements specified in 4.1.1 to 4.1.4 36 C270 – 03b Standard Specification for Mortar for Unit Masonry1 4.1.1 Cementitious Materials 37 C270 – 03b Standard Specification for Mortar for Unit Masonry1 4.1.2 Aggregates 38 How sand affects mortar November 1994 Well-graded sand features a well-distributed mix of particles of varying sizes, which minimizes voids (see illustration). Sand that is too fine has more surface area to coat. Coarser sand particles result in larger voids to fill. As a result, mortar made with sand that is too fine or too coarse contains more water per unit volume, which decreases the mortar’s strength. Excessively coarse or fine sand also makes mortar less workable. 39 not in binder C144 – 03 Standard Specification for Aggregate for Masonry Mortar1 4.4 When an aggregate fails the gradation limits specified in 4.1 and 4.2, it may be used provided the mortar can be prepared to comply with the aggregate ratio, water retention, and compressive strength requirements of the property specifications of Specification C 270. 40 November 1994 How sand affects mortar Masonry specialist John Melander of the Portland Cement Association (PCA) says that in many regions, most sands do not meet ASTM C144 gradation limits and must be qualified under this procedure. 41 not in binder C270 – 03b Standard Specification for Mortar for Unit Masonry1 4.1.3 Water 42 C270 – 03b Standard Specification for Mortar for Unit Masonry1 4.1.4 Admixtures – Admixtures such as coloring pigments, air-entraining agents, accelerators, retarders, water-repellent agents, antifreeze compounds , and other admixtures shall not be added to mortar unless specified. Coloring pigments shall conform to Specification C979. Calcium chloride, when explicitly provided for in the contract documents, is permitted to be used as an accelerator in amounts not exceeding 2% by weight of the portland cement content or 1% by weight of the masonry cement content, or 43 both, of the mortar. C270 – 03b Standard Specification for Mortar for Unit Masonry1 Note 1 – If calcium chloride is allowed, it should be used with caution as it may have a detrimental effect on metals and on some wall finishes. 44 C270 – 03b Standard Specification for Mortar for Unit Masonry1 4.1.4 Admixtures 45 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 46 C270 – 03b Standard Specification for Mortar for Unit Masonry1 5. Requirements 5.1 Unless otherwise stated, a cement/lime mortar, a mortar cement mortar, or a masonry cement mortar is permitted. 47 Requirements 48 ASTM C 270 Material Requirements Measuring and Mixing Proportion Specification • Proportion in Accordance with Table 1 • No Mortar Tests Required Property Specification • Laboratory Tests of Mortar Required to Meet Table 2 • Control Field Proportions to Laboratory Established Mix Design 49 C270 – 03b Standard Specification for Mortar for Unit Masonry1 TABLE 1 Proportion Specification Requirements (default) Proportions by Volume (Cementitious Materials) Mortar CementLime Mortar Cement or Masonry Cement Type Portland Cement or Blended Cement Mortar Cement or Masonry Cement M S N Hydrated Lime or Lime Putty M 1 - - - ¼ S 1 - - - over ¼ to ½ N 1 - - - over ½ to 1¼ O 1 - - - over 1¼ to 2½ M 1 - - 1 - M - 1 - - - S ½ - - 1 - S - - 1 - - N - - - 1 - O - - - 1 - Aggregate Ratio (Measured in Damp, Loose Conditions) Not less than 2¼ and not more than 3 times the sum of the separate volumes of cementitious materials 50 Type S Mortar PCL PC HL Ratio Sand 1 ¼ 3 1 + ¼ = 1¼ x 3 = 3¾ 1 : ¼ : 3¾ 51 C270 – 03b Standard Specification for Mortar for Unit Masonry1 TABLE 1 Proportion Specification Requirements (default) Proportions by Volume (Cementitious Materials) Mortar CementLime Mortar Cement or Masonry Cement Type Portland Cement or Blended Cement Mortar Cement or Masonry Cement M S N Hydrated Lime or Lime Putty M 1 - - - ¼ S 1 - - - over ¼ to ½ N 1 - - - over ½ to 1¼ O 1 - - - over 1¼ to 2½ M 1 - - 1 - M - 1 - - - S ½ - - 1 - S - - 1 - - N - - - 1 - O - - - 1 - Aggregate Ratio (Measured in Damp, Loose Conditions) Not less than 2¼ and not more than 3 times the sum of the separate volumes of cementitious materials 52 Type S Mortar MC MC 1 Ratio 3 1x3= Sand 3 1:3 53 Type S Mortar Example – Make 1 cubic yard of mortar 1cy = 27cf MC Sand 1 3 = x 27 x = 9cf = 9 sacks of masonry cement 9cf sacks + 27cf sand = 27cf or 36cf ? 54 Masonry Information Masonry Mortars 55 C270 – 03b Standard Specification for Mortar for Unit Masonry1 TABLE 2 Property Specification Requirements Mortar Cement Lime Mortar Cement Masonry Cement Type Average Compressive Strength at 28 days, min, psi Water Retention, min, % Air Content, max, % M 2500 75 12 S 1800 75 12 N 750 75 14 O 350 75 14 M 2500 75 12 S 1800 75 12 N 750 75 14 O 350 75 14 M 2500 75 18 S 1800 75 18 N 750 75 20 O 350 75 20 Aggregate Ratio (Measured in Damp, Loose Conditions) Not less than 2¼ and not more than 3½ times the sum of the separate volumes of cementitious materials 56 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 57 C270 – 03b Standard Specification for Mortar for Unit Masonry1 6. Test Methods 58 C270 – 03b Standard Specification for Mortar for Unit Masonry1 6. Test Methods 59 C270 – 03b Standard Specification for Mortar for Unit Masonry1 Note 4 – Air content of non-air-entrained portland cement-lime mortar is generally less than 8%. 60 C270 – 03b Standard Specification for Mortar for Unit Masonry1 6. Test Methods 61 Air Content PCL 3 to 5% Bond Strengths Similar Mortar Cement Masonry Cement 8 to 12% 12 to 18% Type S PCL > Type S Mas Cem 3000psi 2200psi Less 62 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 63 C270 – 03b Standard Specification for Mortar for Unit Masonry1 7. Construction Practices 7.1 Storage of Materials – Cementitious materials and aggregates shall be stored in such a manner as to prevent deterioration or intrusion of foreign material. 64 C270 – 03b Standard Specification for Mortar for Unit Masonry1 7.2 Measurement of Materials – The method of measuring materials for the mortar used in construction shall be such that the specified proportions of the mortar materials are controlled and accurately maintained. 65 Gauging the Amount of Sand 1 cu ft = 7 to 8 shovels 1 : 3 (21 to 24 shovels) 66 Gauging the Amount of Sand Gauging Uses: 20 shovels/batch mixer Gage: 5 shovels/bucket 0.67 ft3 5 gallon bucket 20/5 = 4 buckets/mixer 0.67ft3 x 4 = 2.68ft3 2¼ ft3 < 2.68 ft3 < 3 ft3 yes 67 C270 – 03b Standard Specification for Mortar for Unit Masonry1 7.3 Mixing Mortars – All cementitious materials and aggregate shall be mixed between 3 and 5 min in a mechanical batch mixer with the maximum amount of water to produce a workable consistency. 68 C270 – 03b Standard Specification for Mortar for Unit Masonry1 7.4 Tempering Mortars – Mortars that have stiffened shall be retempered by adding water as frequently as needed to restore the required consistency. No mortars shall be used beyond 2 ½ h after mixing. 69 C270 – 03b Standard Specification for Mortar for Unit Masonry1 7.5 Climatic Conditions – Unless superseded by other contractual relationships or the requirements of local building codes, hot and cold weather masonry construction relating to mortar shall comply with the Masonry Industry Council’s “Hot and Cold Weather Masonry Construction Manual.” 70 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 71 C270 – 03b Standard Specification for Mortar for Unit Masonry1 8. Quality Assurance 8.1 Compliance to this specification is verified by confirming that the materials used are as specified, meet the requirements as given in Section 2.1, and added to the mixer in the proper proportions. 72 C270 – 03b Standard Specification for Mortar for Unit Masonry1 8.2 Test Method C780 is suitable for the evaluation of masonry mortars in the field. However, due to the procedural differences between Specification C270 and C780, the compressive strength values resulting from field sampled mortars are not required nor expected to meet the compressive strength requirements of the property specification of Specification C270, nor do they represent the compressive strength of the mortar in the wall. 73 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices While visual observation of the batching process is important, it is not practical or necessary for an inspector to watch the proportioning of every batch. One thing that can be done – with quick results – is sample the fresh mortar as mixed and calculate how much sand it contains relative to cement. As long as the individual ingredients all meet their own standards, the only thing to check to assure mortar quality is its proportions. This is exactly what the mortar aggregate ratio does and the process is described in ASTM C780. 74 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices ASTM C780 … contains guidance for testing masonry mortars. The mortar aggregate ratio, Annex 4, entails sampling the fresh mortar as mixed, then separating the materials and calculating how much sand it contains relative to cement. 75 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices The Basic Test 1. Take a sample of wet mortar and one of sand. 2. Place sample of mortar into two jars of alcohol. (Alcohol stops cement hydration.) Place sand into a different jar or a plastic bag. 76 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices 3. 4. Agitate the mortar jars to mix the alcohol throughout the sample, breaking up the cement and sand. For mortar jar #1, the alcohol is burned off in the lab, and the remaining material is oven dried to determine the water content. 77 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices 5. For mortar jar #2 and jar #3 with sand, wet sieve each sample. For the mortar sample, the finer materials are assumed to represent the cementitious materials and are washed through a sieve to leave the sand particles behind. The sand sample allows for a correction of fine particles. 78 not in binder Masonry Today Mortar Testing for Quality Assurance: Best Practices 6. 7. Weigh the sample in various conditions: wet, oven dried, after removal of alcohol. This allows the determination of weight of the dry mortar and dry aggregates. Calculate the mortar aggregate ratio. A simple ratio of sand ratio of sand to cement should give something very close to the mortar proportions originally chosen, such as 3:1. 79 C270 – 03b Standard Specification for Mortar for Unit Masonry1 8.3 Test Method C1324 is available to determine the proportions of materials in hardened masonry mortars. There is no ASTM method for determining the conformance of a mortar to the property specifications of Specification C270 by testing hardened mortar samples taken from a structure. 80 C270 – 03b Standard Specification for Mortar for Unit Masonry1 Note 12 – Where necessary, testing of a wall or a masonry prism from the wall is generally more desirable than attempting to test individual components. 81 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 82 Function Hold units together Accommodate unit tolerances 83 Function Provide water penetration resistance Hold units apart 84 Function Variety of colors and textures 85 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 86 Properties Plastic (Mason) Hardened (Designer) Workability Flow Water Retentivity Stiffening Characteristics Board Life Bond Extensibility/Plastic Flow Compressive Strength Durability 87 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.4 Masonry mortars have two distinct, important sets of properties, those of plastic mortars and those of hardened mortars. Plastic properties determine a mortar’s construction suitability, which in turn relate to the properties of the hardened mortar and, hence, of finished structural elements. Properties of plastic mortars that help determine their construction suitability include workability and water retentivity. Properties of hardened mortars that help determine the performance of the finished masonry include bond, durability, elasticity, and 88 compressive strength. C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.5.1 Workability – Workability is the most important property of plastic mortar…Workability is a combination of several properties, including plasticity, consistency, cohesion, and adhesion, which have defied exact laboratory measurement. The mason can best assess workability by observing the response of th mortar to the trowel. 89 Workability Most important plastic property Supports weight of units Adheres to vertical surfaces Spreads easily 90 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.5.3 Flow – Initial flow is a laboratory measured property of mortar that indicates the percent increase in diameter of the base of a truncated cone of mortar when it is placed on a flow table and mechanically raised ½ in. and dropped 25 times in 15 s. 91 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.5.4 Water Retentivity – Water retentivity is a measure of the ability of mortar under suction to retain its mixing water. This mortar property gives the mason time to place and adjust a masonry unit without the mortar stiffening. Water retentivity is increased through higher lime or air content, addition of sand fines within allowable gradation limits, or use of water retaining materials. 92 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.5.5 Stiffening Characteristics – Hardening of plastic mortar relates to the setting characteristics of the mortar, as indicated by resistance to deformation. 93 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.1 Bond – Bond is probably the most important single physical property of hardened mortar. It is also the most inconstant and unpredictable. Bond actually has three facets; strength, extent and durability. Because many variables affect bond, it is difficult to devise a single laboratory test for each of these categories that will consistently yield reproducible results and which will approximate construction results. These variables include air content and cohesiveness of mortar, elapsed time between spreading mortar and laying masonry unit, suction of masonry unit, water retentivity of mortar, pressure applied to masonry joint during placement and tooling, texture of masonry unit’s 94 bedded surfaces, and curing conditions. Bond Complete and intimate contact between mortar and unit is essential for good bond 95 Masonry Information Mortar Cement: Product Data Sheet Bond Strength: The mortar cement specification is the only ASTM masonry material specification that includes bond strength performance criteria. 96 Board Life Retempering 97 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.3.1 The compressive strength of mortar depends largely upon the cement content and the water-cement ratio. The accepted laboratory means for measuring compressive strength is to test 2 in. cubes of mortar. 98 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.3.2 …Often overlooked is the size/shape of mortar joints in that the ultimate compressive load carrying capacity of a typical 3/8 in. bed joint will probably be well over twice the value obtained when the mortar is tested as a 2 in. cube… 2x 2 in. cube = 3/8 in. jt. 99 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.3.2 …Mortars should typically be weaker than the masonry units, so that any cracks will occur in the mortar joints where they can more easily be repaired. 100 Durability Barracks at Fort Wayne in Detroit 101 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.4 Durability – The durability of relatively dry masonry which resists water penetration is not a serious problem. The coupling of mortars with certain masonry units, and design without exposure considerations, can lead to unit or mortar durability problems. It is generally conceded that masonry walls, heated on one side, will stand many years before requiring maintenance, an indication of mortar’s potential longevity. Parapets, masonry paving, retaining walls, and other masonry exposed to freezing while saturated represent extreme exposures and 102 thus require a more durable mortar. C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.6.4.1 …Properly entrained air in masonry mortar generally increases its resistance to freeze-thaw damage where extreme exposure (such as repeated cycles of freezing and thawing while saturated with water) exists. 103 Masonry Information Masonry Cement: Product Data Sheet The ability to endure the extremes of repeated freeze-thaw cycles without deterioration is critical to the long-term performance of mortar. Research shows that air entrainment levels of at least 10 to 12 percent are needed to provide effective resistance to freeze-thaw deterioration in masonry mortars. Masonry cement mortars have greater resistance to freeze-thaw deterioration than nonair-entrained-portland cement-lime mortars. This superior performance can be attributed to the controlled air content of masonry cement mortars. 104 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.9.3.2 Mortar generally bonds best to masonry units having moderate initial rates of absorption (IRA), from 5 to 25g/min-30 in.2, at the time of laying. More than adequate bond can be obtained, however, with many units having IRA’s less than or greater than these values. A measure of the suction of water upward into a dry brick from a bed face during one minute of exposure. 105 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.9.3.3 The extraction of too much or too little of the available water in the mortar tends to reduce the bond between the masonry unit and the mortar. A loss of too much water from the mortar can be caused by low water retentivity mortar, high suction masonry units, or dry, windy conditions. When this occurs, the mortar is incapable of forming a complete bond when the next unit is placed. Where lowering the suction by prewetting the units is not proper or possible, the time lapse between spreading the mortar an laying of a masonry unit should be kept to a minimum. When a very low suction masonry unit is used, the unit tends to float and bond is difficult to accomplish. 106 C270 – 03b Standard Specification for Mortar for Unit Masonry1 There is no available means of increasing the suction of a low suction masonry unit, and thus the time lapse between spreading the mortar and placing the unit may have to be increased. X1.9.3.4 Mortars having higher water retentivity are desirable for use in summer or with masonry units having high suction. Mortars having lower water retentivity are desirable for use in winter or with masonry units having low suction. 107 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X1.9.5.2 Tooling of the mortar joint should be done when its surface is thumb-print hard utilizing a jointer having a diameter slightly larger than the mortar joint width. Joint configurations other than concave can result in increased water permeance of the masonry assemblage. Striking joints with the same degree of hardness produces uniform joint appearance. Finishing is not only for appearance, but to seal the interface between mortar and masonry unit, while densifying the surface of the mortar joint. 108 Mortar Joints Exterior/Interior Concave 109 Mortar Joints Exterior/Interior Concave Vee 110 Mortar Joints Exterior/Interior Concave Vee Grapevine 111 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered 112 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered Beaded 113 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered Beaded Struck 114 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered Beaded Struck Flush 115 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered Beaded Struck Flush Raked 116 Mortar Joints Exterior/Interior Concave Vee Grapevine Interior Weathered Beaded Struck Flush Raked Extruded 117 not in binder TABLE 2. MORTAR PROPERTIES Cementitious Materials Portland Cement:Lime Type Mortar Cement Masonry Cement S N O S N S N Initial 110 110 108 114 115 113 115 Final 90.0 100 99.0 92.0 87.0 89.0 100 Water Retention, % 81.8 90.9 91.7 80.7 75.6 78.8 87.0 Cone Penetration, mm 56 57 58 53 51 53 64 7 day, psi 3718 1745 674 2722 2471 2635 1069 28 day, psi 4248 2132 882 3220 3285 3157 1472 Air Content, % 1.5 1.1 1.4 8.7 9.3 13.8 15.8 Flow Compressive Strength2 1Average of three measurements on 2” cubes 2Measured 118 not in binder TABLE 3. FLEXURAL BOND STRENGTHS Cementitious Material and Mortar Type Brick IRA gm/30 in2/min 1.00 4.30 15.1 Flexural Bond Strength Data Portland Cement:Lime Mortar Cement Masonry Cement S N O S N S N Average of 30, psi 92.40 80.96 65.03 94.18 82.17 77.42 61.94 Standard Deviation, psi 19.22 15.98 9.65 19.61 11.87 11.85 7.28 Coefficient of Variation 19.62 18.05 13.76 18.93 14.31 14.77 11.52 Average of 30, psi 109.0 105.4 80.47 120.7 127.2 122.0 104.6 Standard Deviation, psi 16.96 11.72 10.38 17.03 22.97 19.59 21.10 Coefficient of Variation 14.68 10.75 12.72 13.22 17.85 15.37 20.11 Average of 30, psi 101.4 115.1 94.00 Standard Deviation, psi 24.00 20.65 9.21 Coefficient of Variation 22.92 16.94 9.58 119 Masonry Information Masonry Cement: Product Data Sheet Several factors influence drying shrinkage of masonry mortars, including water content, rate of drying, sand properties, moisture content and absorption of the masonry units, and cementitious material properties. Results of laboratory tests shown in Fig. 1 indicate that the drying shrinkage of masonry cement mortars is about half that of portland cement-lime mortars. 120 Masonry Information Masonry Cement: Product Data Sheet 121 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 122 Selection MIM suggests the mortar type selected be the weakest that will satisfy structural requirements. 123 Compatibility Mortar type should be correlated with the particular masonry unit to be used because certain mortars are more compatible with certain masonry units. 124 C270 – 03b Standard Specification for Mortar for Unit Masonry1 TABLE X1.1 Guide for the Selection of Masonry Mortars Mortar Type Location Building Segment Recommended Alternative Exterior, above grade Load-bearing wall Non-load bearing wall Parapet wall N O N S or M N or S S Exterior, at or below grade Foundation wall, retaining wall, manholes, sewers, pavements, walks, and patios S M or N Interior Load-bearing wall Non-bearing partitions N O S or M N Interior or Exterior Tuckpointing See Appendix X3 See Appendix 125 X3 Recommendations Above Grade Wall System Veneer Reinforced Unreinforced Mortar Type N N or S S Below Grade S or M 126 C270 – 03b Standard Specification for Mortar for Unit Masonry1 TABLE X1.1 Guide for the Selection of Masonry Mortars Mortar Type Location Building Segment Recommended Alternative Exterior, above grade Load-bearing wall Non-load bearing wall Parapet wall N O N S or M N or S S Exterior, at or below grade Foundation wall, retaining wall, manholes, sewers, pavements, walks, and patios S M or N Interior Load-bearing wall Non-bearing partitions N O S or M N Interior or Exterior Tuckpointing See Appendix X3 See Appendix 127 X3 Recommendations Above Grade Wall System Veneer Reinforced Unreinforced Mortar Type N N or S S 128 Recommendations Above Grade Wall System Veneer Reinforced Unreinforced Mortar Type N N or S S 129 1999 Spec Unit Strength Method Table 2 – Compressive strength of masonry based on the compressed strength of concrete masonry units and type of mortar used in construction Net area compressive strength of concrete masonry units, psi Type M or S mortar Type N mortar Net area compressive strength of masonry, psi 1250 1300 1000 1900 2150 2800 3050 2000 3750 4050 2500 4800 5250 3000 1900 1500 1350 130 Recommendations Above Grade Wall System Veneer Reinforced Unreinforced Mortar Type N N or S S 131 1999 Code Table 2.2.3.2 – Allowable flexural tension for clay and concrete masonry, psi Mortar types Masonry type Normal to bed joints Solid units Hollow units Ungrouted Fully grouted Parallel to bed joints in running bond Solid units Hollow units Ungrouted and partially grouted Fully grouted Portland cement/lime or mortar cement Masonry cement or air entrained portland cement/lime M or S N M or S N 40 30 24 15 25 68 19 58 15 41 9 29 80 60 48 30 50 38 30 19 80 60 48 30 132 Mortar Products ASTM C 270 Scope Referenced Documents Specification Limitations Materials Requirements Test Methods Construction Practices Quality Assurance Function Properties Selection Tuckpointing Application 133 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X3.3 Selection Guide – Use tuck pointing mortar of the same or weaker composition as the original mortar. See Table X3.1. 134 C270 – 03b Standard Specification for Mortar for Unit Masonry1 X3.5 Mixing: X3.5.1 Dry mix all solid materials. X3.5.2 Add sufficient water to produce a damp mix that will retain its shape when pressed into a ball by hand. Mix from 3 to 7 min, preferable with a mechanical mixer. X3.5.3 Let mortar stand for not less than 1hr nor more than 1 ½ h for prehydration. X3.5.4 Add sufficient water to bring the mortar to the proper consistency for tuck pointing, somewhat drier than mortar used for laying the units. X3.5.5 Use the mortar within 2 ½ h of its initial mixing. Permit tempering of the mortar 135 within this time interval. Moisture Resistance of Brick Masonry Maintenance Tuck-pointing Mortar Joints 136 137