ALBERTA INFRASTRUCTURE AND TRANSPORTATION SPECIFICATION FOR CONCRETE PATCHING MATERIAL

Transcription

1 ALBERTA INFRASTRUCTURE AND TRANSPORTATION TECHNICAL STANDARDS BRANCH B391- MAY 04 SPECIFICATION FOR CONCRETE PATCHING MATERIAL SCOPE - The approval procedures and requirements necessary for classifying a product for use as a concrete patching material are specified. 1.0 GENERAL 1.1 INTRODUCTION This specification covers the supply of packaged, dry cementitious mortar or concrete materials for the repair of concrete structures. Aggregates must be included as a component of the packaged material and only the mixing liquid, as specified by the manufacturer, is to be added in the field. The specification covers the approval procedures and requirements for certification of all patching material products. Patching materials will be used to repair areas damaged by impact or deterioration. The patch must withstand freeze-thaw cycles, exposure to de-icing salts, extreme temperatures, rapid temperature changes, dynamic and static stresses related to structural conditions, abrasion from traffic and impact loading. The current edition of all codes and standards referred to within this specification will be applied at the time of testing. BT006, Test Procedure for Measuring Shrinkage/Expansion of Concrete Patching Materials and TLT520, Total Chloride Content in Cement, Mortar and Concrete, shall be used in conjunction with this specification. The properties of patching materials are affected by curing conditions. The curing of laboratory samples shall be carried out, with limitations as described in 3.6.1, in the same manner as prescribed in the manufacturer's specified field curing. The manufacturer agrees to amend his field curing instructions to users as stated above when submitting a product to the Department for approval. B391-MAY 04 Page 1 of 15

2 1.2 CLASSIFICATION OF PATCHING MATERIALS The repair location; weather condition (at time of placement); and the period before traffic must resume; will dictate the type of patching material to be selected. Concrete patching materials are classified into 4 types as follows: (a) (b) (c) (d) Type NH - Normal horizontal patches are used to repair areas such as bridge deck potholes or curb top spalls. These products are generally used during the summer when good weather conditions prevail. Traffic or an overlay will be placed after three days of curing. The product shall be poured and must be workable to allow for proper finishing. Type OH-V - Overhead or vertical patches are used to repair areas such as high load damage to precast girders, spalling on the underside of bridge decks, inside face of curbs, pier caps and abutment seats and backwalls. These products are generally used during the summer when good weather conditions prevail. Patching material shall be of a consistency to be applied by trowelling rather than forming. Type LTH - Low temperature horizontal patches are used to repair areas similar to those described in NH when the ambient temperature is in the range of 0 o to 5 o C and rising and generally during the spring and late fall. The product shall be poured and must be workable to allow for proper finishing. Type HEH - High early horizontal patches are used to repair areas similar to those described in NH. These products are generally used during the summer when good weather conditions prevail and a high early strength is required in order that traffic may be allowed to resume. The product must be poured and will be workable to allow for proper finishing. 2.0 APPROVAL PROCEDURES 2.1 ARRANGEMENT FOR TESTING The Supplier/Manufacturer shall have his product tested for approval according to the procedures as outlined in this specification. Once approved the product will be included on the Department approved product list. The tests are to be carried out by an independent, CSA certified laboratory at the Supplier s/manufacturer's expense. B391-MAY 04 Page 2 of 15

3 The test results shall be submitted by the Supplier/Manufacturer to: Alberta Infrastructure and Transportation Technical Standards Branch 2 nd Floor, Twin Atria Building Avenue Edmonton, Alberta, T6B 2X3 Attention: Clarence Wong, Bridge Materials Engineer Telephone: (403) FAX: (403) Test results will become the property of the Department. The Department reserves the right to publish the test information for public use. Results of testing may be submitted at any time provided all the requirements are met. The Department will update the approval list after a review has been undertaken to ensure that all requirements are satisfied. 2.2 LABORATORY TEST REPORT The report prepared by the testing laboratory shall include all individual test results from the five required tests as well as the manufacturer's instructions used for mixing and curing. The report shall state the maximum aggregate size used in the mix. Product batch number, designation, date of manufacture and comments as to its workability shall be shown. In addition, the product data sheet, materials safety data sheet and relative bulletins for each product tested shall be included with the test report. In addition to the requirements of Section 3.3, the Manufacturer shall submit to the Department a set of 3 compression strength cubes and 1.0 kg representative sample of the concrete patching material submitted to the lab for testing. 2.3 EVALUATION OF TEST RESULTS The test results will be evaluated as per the rating scales shown in Section 3.0. The individual ratings for the six tests will be added together and divided by 6 to obtain the average rating. In cases where the patching material cannot be extended with pea gravel, the individual ratings for the five tests will be added together and divided by 5 to obtain the average rating. To be considered for approval, a product must have an average rating of 6.0 or greater with no individual rating being less than 4.0 and only one out of the five or six individual ratings can be equal to 4.0. The rating difference between individual specimens shall not vary by more than an increment of 1.0 when rated using the scales shown in Section 3.0. In addition, the patching material must also meet the requirements of Sections and 3.9. B391-MAY 04 Page 3 of 15

4 3.0 QUALIFYING TESTS 3.1 SAMPLE MIXING AND CASTING The sample size of each product submitted for testing shall be large enough to allow all specimens to be cast from the same batch. The specimen shall be mixed and cured according to manufacturer's directions and in accordance with the requirements of this section. The concrete mix used for the base of the shear bond test shall be a 30 MPa design mix. All material and equipment shall be brought to and maintained at a temperature of 23 o C (±2 C) for the duration of the tests listed below Initial Curing, All Samples 3.2 SPECIMEN AGE Unless otherwise specified, all test specimens shall be kept in the mold for 24 hours, without any covers, at 50% (± 2%) Relative Humidity and 23 o C (± 1 o C). The following table shows the product classification and the age of the specimen at time of testing. Product Type Compressive Strength Shear Bond Water Absorption Linear Shrinkage Salt Scaling NH OH-V LTH 24 hours 24 hours HEH 4 hours 24 hours * in days except where noted. 3.3 COMPRESSIVE STRENGTH AND UNIT WEIGHT Compressive strength shall be carried out as per CAN/CSA-A5-93. Unit weight shall be recorded for each test specimen after it is demolded. B391-MAY 04 Page 4 of 15

5 With the exception of the LTH product, the 50 mm cube specimens shall be cured for 4 hours, 24 hours or 28 days as shown in the table in section 3.2. The LTH product specimen shall be cured at 3 o C for the first 24 hours. Mixing liquid and dry LTH packaged material used to make the cubes shall be stored at a temperature of 3 o C and the tests started only when the mixing liquid and dry pack material has achieved a uniform temperature of 3 C throughout. Products where the Manufacturer specifies that the concrete patching material can be extended with pea gravel (6-13 mm), it shall be extended in accordance with the Manufacturer s specification. Mixing liquid and dry packaged LTH material shall be stored at a temperature of 3 C prior to and during the forming of the specimens. LTH products shall be cured at 3 C for the first 24 hours. Three compressive strengths shall be performed on 75 mm x 150 mm cylindrical specimens for each time period for the following Classifications: Type NH, compressive strengths at 24 hours, 3 days, 7 days and 28 days Type HEH, compressive strengths at 45 minutes, 2 hours, 4 hours, 24 hours, 7 days and 28 days Type LTH, compressive strengths at 24 hours, 3 days, 7 days and 28 days In addition, three unit weights shall be performed. The rating of the products from the test results will be done according to the scales in section 3.3.1, and Compressive Strength Rating Scale for Product Types NH and OH-V The following is the rating scale for specimens cured for 28 days. Rating 1 < to 35.9 Compressive Strength (MPa) to 37.9 or > to 39.9 or 80.0 to to 41.9 or 76.0 to to 43.9 or 72.0 to to 45.9 or 68.0 to to 47.9 or 64.0 to to 49.9 or 60.0 to to 59.9 B391-MAY 04 Page 5 of 15

6 3.3.2 Compressive Strength Rating Scale for Product Types HEH and LTH The following is the rating scale for HEH specimens cured for 4 hours or LTH specimens cured for 24 hours. Rating Compressive Strength (MPa) 1 < to to to to to to to to > Compressive Strength Rating Scale for Product Types NH, HEH and LTH Extended with Aggregate The following is the rating scale for NH specimens cured for 28 days and HEH specimens cured for 4 hours or LTH specimens cured for 24 hours. Rating Compressive Strength (MPa) 1 < to to to to to to to to > 30.0 B391-MAY 04 Page 6 of 15

7 3.4 SHEAR BOND STRENGTH Shear bond strength shall be carried out as per ASTM C882, Standard Test Method for Bond Strength of Epoxy - Resin Systems Used with Concrete. This test method determines the bond strength of patching material cast onto slanted surfaces of 30 MPa concrete which has been cured for 28 days. With the exception of LTH products, the test specimens shall be 100 x 200 mm cylinders cured for 24 hours or 28 days as shown in the table in section 3.2 for the various product classifications. Mixing liquid and dry packaged LTH material shall be stored at a temperature of 3 o C and maintained at an uniform temperature of 3 C prior to and during the forming of the specimens. LTH products shall be cured at 3 o C for the first 24 hours. The drying time for the 30 MPa concrete slant surface base prior to patching material shall be a minimum of one day. The base specimens shall be prepared by sandblasting the slant surface such that approximately 10 grams of material is removed. The rating of the products from the test results will be done according to the scale in section Bond Strength Rating Scale for All Product Types The following is the rating scale for specimens cured for 24 hours or 28 days as specified in Section 3.2 Rating Bond Strength (MPa) 1 < to to to to to to to to > 14.0 B391-MAY 04 Page 7 of 15

8 3.5 WATER ABSORPTION Water absorption shall be determined as follows: (a) Cast 2 specimens 150 mm x 150 mm x 50 mm for each product classification and use the average result for rating. Cure at 50% R.H. and 23 o C (±1 o C) for initial 24 hours. (b) Demould specimens after 24 hours and moist cure for a total of 14 days in moist room at 100% R.H. and 23 o C (±1 o C). (c) (d) (e) (f) (g) Oven dry specimens at 80 o C until constant weight, (i.e. the difference between any two successive weights is less than 0.5% of lowest weight obtained). Cool specimens to room temperature in a desiccator, weigh and designate this mass as oven dry mass. Submerge to 25 mm depth in water bath for 24 hours. Lightly towel to surface dry, re-weigh and designate this mass as Surface Saturated Dry (SSD) mass. Calculate percent absorption as the mass of water absorbed based on the oven dry mass. Absorption (%) = SSD Mass - Oven Dry Mass x 100 Oven Dry Mass The rating of the products from the test results will be done according to the scale in section B391-MAY 04 Page 8 of 15

9 3.5.1 Absorption Rating Scale for All Product Types The following is the rating scale for specimens cured for 14 days. Rating Absorption (%) 1 < to to to to to to to to > LINEAR SHRINKAGE Linear shrinkage shall be carried out as per BT006, Test Procedure for Measuring Shrinkage/Expansion of Concrete Patching Materials. This test method determines the length change of hardened hydraulic-cement mortar due to causes other than externally applied forces and temperature change. The test specimens shall be 25 x 25 x 285 mm for maximum aggregate sizes up to 5 mm and 75 x 75 x 285 mm for maximum aggregate sizes between 5 mm and 25 mm Initial Curing of Length Change Specimens This procedure allows for evaluating the length change of concrete patching materials under two curing regimes. These curing requirements are referred to as Standard Curing and Manufacturer's Curing (Optional). The difference in curing affects the initial curing period of 24 hours from time of casting. Under Standard Curing, one set of three specimens shall be cast and cured at 50% Relative Humidity and 23 o C (± 1 o C). Neither the exposed surfaces nor the moulds holding the samples shall be covered up during this period. B391-MAY 04 Page 9 of 15

10 Under the optional Manufacturer's Curing, a second set of three specimens are prepared and cured for 24 hours at 23 o C (± 1 o C), using wet burlap or plastic covers or water spray in a moist room, or both. Alternatively or in conjunction with these wet curing methods, the specimens may be sprayed with a commercially available proprietary curing compound during the first 24 hours. OH-V products are difficult to wet-cure in the field, laboratory specimens of this type may only be cured with a commercially available proprietary curing compound during the initial curing period. If a product meets the requirements of Section 2.3 under Manufacturer's Curing, but fails to meet the requirements under Standard Curing, the manufacturer shall ensure that his curing instructions or included with each shipment. If moist curing in a fog room was used the manufacturer's curing instructions shall specify continuous wetting by a water sprinkler system in the field for the same period that was requested for initial fog room curing. If plastic covers were used to reduce shrinkage in the laboratory, they shall be required for field usage Length Change Measurement (See BT006) Except for short periods required to perform length change measurements, all length change specimen shall be demoulded after 24 hours and stored in a humidity and temperature controlled chamber at 50 ± 2% Relative Humidity and 23 o C (± 1 o C). Length change shall be measured at the age of 1 day ± 1 hour, 3 days ± 4 hours, 7 days ± 8 hours and 28 days ± 12 hours, with reference to the length of each prism at time of casting as outlined in Specification BT006. The maximum allowed expansion for the first day is 0.075%. Products exceeding this limit under both curing regimes will be rejected. The report shall describe the curing regime under which a product passes the requirements of Section 2.3. Specimens shall be weighed at time of demoulding and again at the conclusion of the testing. The rating of the products from the test results will be done according to the scale in section B391-MAY 04 Page 10 of 15

11 3.6.3 Shrinkage Rating Scale for All Product Types The following is the rating scale for specimens aged for 28 days. Rating 3.7 SALT SCALING Linear Shrinkage (%) 1 > to to to to to to to to < (-) Shrinkage Salt scale shall be carried out as per ASTM C672, Standard Test Method for Scaling Resistance of Concrete Surfaces Exposed to De-icing Chemicals. This test method determines the resistance to scaling of a horizontal surface exposed to freeze-thaw cycles in the presence of de-icing chemicals. The following modifications will apply to this test: (a) (b) (c) Proportioning - the patching product shall be prepackaged by the supplier. Specimen - shall have a 50 mm depth and the dike is to be placed on the under or formed side of the specimen. To ensure all form oil is removed the formed surface shall be prepared by light sandblasting, such that approximately 15 grams of material removed. Three specimens shall be formed for testing. Mixing and Testing - machine mix and test according to the applicable provisions of CSA CAN3-A5. B391-MAY 04 Page 11 of 15

12 (d) Curing - a period of 14 days, the first 7 days in moist storage and the last 7 days under controlled chamber at 50% RH and 23 C (±1 C). (e) (f) Salt Solution - the de-icing salt shall consist of sodium chloride and water having a concentration such that each 100 ml of solution contains 3 grams of sodium chloride. Mass Loss - Prior to the final visual examination and rating and after each of the 10 cycles, remove the salt solution together with all the flaked off concrete from the surface and place into a watertight container. This procedure is best accomplished by tilting the slab into a 500 mm in diameter funnel and washing the surface of the specimen with the salt solution. The washing should continue until all loose particles are removed from the concrete. The solution shall then be strained through a filter and the residue dried out in an oven at 105 o C to a constant mass. The residue shall be cumulatively weighed after each 10 cycles. This residue shall be defined as the loss of mass and expressed in kilograms per square metre of exposed slab area. The loss of mass shall be calculated to the nearest kg/m 2. (g) Report - measure and report cumulative weight after every 10 cycles, as kg/m 2. Specimens for all product types shall have the mass loss determined every 10 cycles until 50 cycles have been completed. In addition, visual ratings shall be reported for every 10 cycles until 50 cycles have been completed in accordance with ASTM C672 Visual Rating Scale. The rating of the products from the test results will be done according to the scale in section B391-MAY 04 Page 12 of 15

13 3.7.1 Salt Rating Scale for All Product Types The following is the rating scale for specimens after 50 cycles. Rating Mass Loss (kg/m 2 ) 1 > to to to to to to to to < Visual Salt Rating Scale for All Product Types After 50 cycles of testing, the visual rating of each specimen shall be less than 3 in accordance with ASTM C672, visual rating scale. 3.8 YIELD AND UNIT WEIGHT Yield and unit weight shall be measured in accordance with ASTM C387 using the manufacturer s recommended mixing liquid and amount. 3.9 CHLORIDE CONTENT Chloride content shall be carried out in accordance with TLT-520, Total Chloride Content in Cement, Mortar and Concrete. The patching material shall contain no chlorides. Samples formed for the 50 mm compressive strength determination may be used for the testing of chlorides. B391-MAY 04 Page 13 of 15

14 4.0 PACKAGING 4.1 QUALITY AND SIZE Bags shall be multi-layered with the outer layer of strong paper or equivalent and the inner layers of waterproof material. The waterproof material shall have a water vapour transmission not greater than 100 g/m 2 in 24 hours as determined in accordance with Procedure B of ASTM Test Method E96 Maximum weight allowed in a bag is 25 kg. The net weight in each bag shall not vary by more than 2% from that printed on the bag. The volumetric yield shall not vary by more than 2% from that printed on the bag. 4.2 MARKING The following information shall be marked on the outside of each bag: (a) (b) (c) (d) (e) (f) (g) (h) (i) Product name Manufacturer Batch number Weight of bag Date material was manufactured. At time of shipping the product must not have been manufactured for more than 30 days. Shelf Life Yield in cubic metre when mixed with recommended amount of liquid. Mix instructions including recommended amount of water or other liquid component or both to be mixed with the package contents. The recommended length of mixing time or sequence of mixing time or sequence of mixing and resting time in minutes. Curing recommendations. B391-MAY 04 Page 14 of 15

15 5.0 ADDITIONAL REQUIREMENTS 5.1 APPROVED PRODUCT Products meeting this specification will be considered for approval. The approved products will be shown on the approval list as to type, name, manufacturer and Alberta supplier. It will be the responsibility of the Supplier/Manufacturer to retest his product, at his own expense, prior to the end of the 5 year period. The Department will not notify the Supplier/Manufacturer of the expiry date. The approval is valid for 5 years from the date of approval. Any subsequent change in product formulation or future amendments/changes to the Specification for Concrete Patching Material B391 will require a retest for reapproval at the Supplier/Manufacturer s expense. 5.2 QUALITY CONTROL The Supplier/Manufacturer shall be responsible for quality control of the product. He shall sample and test the material as necessary during production to ensure that all material conforms to these specifications, and is consistent with the sample of material that was tested and approved. When requested by the Department, the Manufacturer will submit the quality control data within 30 days. Any subsequent change in the product will require a re-test at the Supplier s/manufacturer s expense. 5.3 RIGHT TO REJECT The Department reserves the right to reject material, and withdraw the product from the approval list should it not meet performance. Failure to pass quality assurance tests will result in withdrawal of the Department s approval. In addition to the requirements of the specification B391, the Department may perform other identification tests to establish that the material delivered to the construction site is identical to the laboratory sample on which approval was based. The material shall meet or exceed all qualifying tests, and shall perform adequately in the field. Unsatisfactory performance, whether short term or long term, shall be grounds for withdrawal of the approval. B391-MAY 04 Page 15 of 15