Aashto t 166 pdf download

Standard Method of Test for Determining Degree of Pavement Compaction of Bituminous Aggregate Mixtures AASHTO Designation: T 230-68 (2000) 1. 1.1. SCOPE This method describes the procedures for determining the degree of pavement compaction of a bituminous-aggregate mixture as related to standard specimens composed of the same materials and within the tolerance of the job mix formula. The values stated in SI units are to be regarded as the standard. 1.2. 2. 2.1. REFERENCED DOCUMENTS AASHTO Standards: W T 166, Bulk Specific Gravity of Compacted Asphalt Mixtures Using Saturated Surface-Dry Specimens T 167, Compressive Strength of Bituminous Mixtures 2.2. ASTM Standard W D 2950, Density of Bituminous Concrete in Place by Nuclear Method 3. 3.1. 3.1.1. 3.1.1.1. SAMPLING AND TESTING Removing the sample from the compacted pavement. Equipment: Any tool suitable for removing intact a square, circle, or core of compacted pavement for the full depth of the course or courses. An impact chisel, a diamond blade pavement saw, a steel density ring, or a diamond bit core drill are suitable for this purpose. The core drill should be equipped to core and retrieve specimens approximately 100 to 150 mm (4 or 6 in.) in diameter. The density ring shall be approximately 150 mm (6 in.) I.D. and approximately 6.4 mm (lI4 in.) less in height than the thickness of the compacted course. A rigid plate or suitable container large enough to hold the sample without distortion after it is removed from the pavement. 3.1.1.2. Ts-2~ T 230-1 AASHTO 3.1.2. 3.1.2.1. Procedure: Method A-A suitable material of appropriate size for preventing the bond between pavement layers shall be placed and its location identified. After pavement has been laid and compacted, cut and remove a square sample from above location. (See Appendix A for typical method.) Method B-When the sample is to be cored, pre-identifying the location of the sample may be eliminated. When the coring operation has been completed, carefully remove sample by use of the core retriever. When the maximum nominal size aggregate in the pavement is 25 mm or less, a 100-mm (4-in.)diameter bit or larger shall be used. When the maximum nominal size aggregate is over 25 mm, a 150-mm (6-in.) diameter bit shall be used. Method C-The 3.1.2.2. 3.1.2.3. 3.1.2.4. sample may be obtained by the Density Ring Method. (SeeAppendix B.) After the pavement sample has been cut or cored, it should be carefully removed. Care should be exercised that the sample is not distorted, bent, cracked, or in any way changed from its physical condition as it was before removal from the pavement. The sample should then be forwarded to the laboratory. If for any reason there should be a delay in shipping the sample to the laboratory, it should be placed in a safe, cool place. Complete identification information should be submitted with the sample. Determination of Specific Gravity of the Sample Taken From the Compacted Pavement: 3.1.2.5. 3.2. 3.2.1. 3.3. 3.3.1. The specific gravity of the sample shall be determined in accordance with T 166. Determination of specific gravity/density of the compacted pavement by nuclear gauge. The specific gravity/density of the compacted pavement may be determined in place by testing in accordance with ASTM D 2950, “Density of Bituminous Concrete in Place by Nuclear Method.” Standard Specimens: 3.4. 3.4.1. Standard specimens shall be prepared from a representative sample of the mix to be tested for compaction, in accordance with T 167 or other acceptable methods. Determination of the specific gravity of a standard laboratory compacted specimen. The specific gravity of the standard specimens shall be determined in accordance with T 166. 3.5. 3.5.1. 4. 4.1. DEGREE OF PAVEMENT COMPACTION The degree of compaction shall be determined by dividing the specific gravity of the pavement specimens by the specific gravity of the standard specimens and shall be expressed as a percentage: Pavement Sp G r Degree of Compaction = Standard Specimen Sp G r Ts-2~ T 230-2 AASHTO --`,,`,`,,,,`,`,`,,`````,,``,,,,-`-`,,`,,`,`,,`--- APPENDIX A Al. A l .l. OBTAINING A SQUARE OF COMPACTED PAVEMENT Place a 300-mm (12-in.) square of cardboard, light sheet metal or metal foil on the particular lane that is being paved. It should not be placed any closer than 0.6 m (2 ft) from the edge of the lane or from a longitudinaljoint. Tie in the four comers of the square by measuring from known points and recording the distances. After the pavement is laid and compacted, nail redheads (nails with a square of red cloth attached to their heads), in the four comers of the square beneath the pavement. This will identify the location of the sample when it is to be cut out and removed. By using either an impact chisel or a diamond blade saw, make cuts in the pavement connecting the four measured points. This will furnish a sample of pavement 300 by 300 mm (12 by 12 in.) that can easily be removed as the bond is broken directly by the cardboard, or sheet metal or metal foil. A l .2. APPENDIX B-DENSITY B1. B1.l. RING METHOD APPARATUS Density Ring-The density ring shall be of steel, approximately 150 mm (6 in.) inside diameter in.) less in height than the thickness of the compacted layer of and approximately 6.4 mm asphalt mix from which the specimen is to be removed. Rings of the required height may be cut from low carbon, cold drawn, seamless, mechanical tubing-150 mm I.D., 6.4 mm (6 in. I.D., '14 in.) wall thickness. The lower part of the outside wall of the ring shall be cut on a bevel (approximately 20") until the bottom edge is approximately 3.2 mm in.) wide. The ring shall be trued so that the top and bottom edges are parallel to each other and perpendicular to the inside wall. The wall shall be cut through at one location as shown in Figure 1. The cut section shall be approximately 1.6 mm (1/16 in.) wide, or as cut by the saw blade. If the cut should open more than is desirable, it may be brought back to the desired dimension by compressing the open-ring in a vise. B1.l.l. 61.1.2. B1.1.3. Ts-2~ T 230-3 AASHTO r3.2 Dimensional Equivalents mm ~ in. % 1/4 3.2 6.4 152.4 6 All dimensions shown in millimeten unless otherwise noted. h = 6.4 mm less than thickness of compacted layer from which the specimen is to be removed. All dimensions are approximate. Notes: 1. 2. Figure l-Typical B1.1.4. Pavement Density Ring A hole approximately 3.2 mm in.) in diameter shall be drilled in the ring wall opposite the cut section. The center of the hole shall be approximately 4.8 mm (3/16 in.) from the upper edge of the ring. By means of the hole, a suitable wire may be attached to the ring to aid in removal of the ring and specimen from the compacted pavement. All edges of the split ring, including the cut section, shall be deburred and made smooth by filing. Ts-2~ T 230-4 AASHTO 1 82. 82.1. PROCEDURE On the base or leveling course on which the asphalt mix is being placed, and at the selected location, place the density ring with beveled edge down ahead of the spreading operation. If desired, a piece of aluminum foil slightly larger than the density ring may be placed between the ring and the base or leveling course. A string may be attached to the short wire affixed to the density ring and led to an area outside the spreading operation. After the spreading machine has passed over the density ring, but before rolling operations are begun, the string and wire are lifted through the uncompacted mix and left on the surface. After rolling operations are complete, the string and wire are lifted from the surface to the location of the density ring and enclosed specimen. By means of the attached wire, and with the aid of a pry (large screwdriver will do), the density ring and the enclosed specimen shall be removed from the pavement. Dry ice in a plastic bag may be used to cool the compacted mix before the ring and specimen are removed. After the ring and specimen are removed, material near the upper edge (above the density ring) which may have been loosened or disturbed during the removal operation, shall be trimmed from the undisturbed portion of the specimen. --`,,`,`,,,,`,`,`,,`````,,``,,,,-`-`,,`,,`,`,,`--- 82.2. 82.3, To remove the specimen from the ring, a strong screwdriver is inserted into the cut-section and turned to expand the ring and allow the specimen to drop out, or to be pushed out. Care must be exercised so the compacted specimen will not be deformed during the removal operation. Ts-2~ T 230-5 AASHTO