1、Standard Method of Test for Determining the Shear Strength at the Interface of Bonded Layers of Portland Cement Concrete AASHTO Designation: T 323-03 (2016)1 Release: Group 1 (April 2016) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Wash
2、ington, D.C. 20001 TS-3c T 323-1 AASHTO Standard Method of Test for Determining the Shear Strength at the Interface of Bonded Layers of Portland Cement Concrete AASHTO Designation: T 323-03 (2016)1Release: Group 1 (April 2016) 1. SCOPE 1.1. This test method covers the determination of the interface
3、shear strength of a drilled concrete core sampled from a bonded concrete overlay pavement or bridge deck. 1.2. This test shall be performed on 100-mm (4-in.) diameter cores of portland cement concrete. 1.3. This test is applicable if, when retrieved by coring, the concrete overlay thickness is at le
4、ast 25 mm (1 in.) and the thickness of the base concrete is at least 50 mm (2 in.). 1.4. This test procedure is based on the Iowa Department of Transportation Test Method No. Iowa 406-B (1984). 1.5. This standard may involve hazardous materials, operations, and equipment. This standard does not purp
5、ort to address all of the safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: T 22, C
6、ompressive Strength of Cylindrical Concrete Specimens 2.2. Other Document: Iowa Test Method No. 406-B, Method of Test for Determining the Shearing Strength of Bonded Concrete, Iowa Department of Transportation, 1984. 3. SUMMARY OF METHOD 3.1. This method consists of applying a continuous load to the
7、 vertical diametral plane of the test specimen along the bonded interface between the overlay concrete and base concrete (Figure 1). 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 323-2 AASHTO L
8、oad, P Load, PExisting ConcreteBonded InterfaceCross-Sectional AreaConcreteReaction ReactionShear Strength (S ) =BLoadAreaSide View Front ViewOverlayFigure 1Loading Scheme Used for the Shear Strength Test 3.2. The load is applied until a shear failure occurs at the bonded interface. 3.3. The bond sh
9、ear strength is calculated by dividing the maximum load attained during the test by the cross-sectional area of the test specimen. 4. SIGNIFICANCE AND USE 4.1. The bond shear strength may be used to assess the integrity of the bond between a bonded concrete overlay and the underlying concrete paveme
10、nt or bridge deck. 5. APPARATUS 5.1. Loading BlockThe loading block used for the bond shear test shall be designed to accommodate a 100-mm (4-in.) diameter test specimen. A typical loading block is illustrated in Figure 2. 5.2. Loading HeadA metal loading head with a concave surface having a 50-mm (
11、2-in.) radius of curvature is required to apply load to the specimen. The loading head shall be 13 mm (0.5 in.) wide. Edges should be rounded by grinding to remove sharp edges. A typical loading head is illustrated in Figure 2. 5.3. Testing MachineThe testing machine shall conform to the requirement
12、s of T 22, possessing sufficient capacity and providing the rate of loading described in Section 6.3. 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 323-3 AASHTO Front View Side ViewLoading Bloc
13、kLoading Head102 mm(4 in.)13 mm(1/2in.)51 mm(2in.)Front View Side ViewFront View Side ViewFigure 2Typical Loading Block and Loading Head 6. PROCEDURE 6.1. Specimen PreparationMeasure the diameter of the core, the thickness of the overlay, and the thickness of the original concrete to the nearest mil
14、limeter (mm) (0.004 in.). 6.2. Specimen PositioningSecure the specimen in the loading block. The bonded interface shall be centered between the edge of the loading block and the edge of the loading head. 6.2.1. Align the loading head adjacent to the bonded interface. The loading head shall rest para
15、llel to the bonded interface on the overlay concrete portion of the specimen. Sample positioning and loading are shown in Figure 3. 6.3. Rate of LoadingApply the load continuously and without shock at a constant rate within the range of 2760 to 3450 kPa/min (400 to 500 psi/min) until failure occurs.
16、 Record the maximum applied load, PMAX, carried by the specimen during the test. 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 323-4 AASHTO LoadUpper PlatenLoading HeadPCC CoreOverlay ConcreteL
17、oading BlockExisting Concrete102 mm (4 in.)Lower Platen13 mm (1/2in.)32 mm (11/8in.)Figure 3Illustration of Sample Positioning and Loading 7. CALCULATIONS 7.1. Calculate the bond shear strength, SB, as follows in Equation 1: SI units: 3MAX10BPSA= (1) Inch-pound units: MAXBPSA= where: SB= bond shear
18、strength, kPa (psi); PMAX= maximum load applied to specimen, N (lb); and A = cross-sectional area of test specimen, mm2 (in.2). and in Equation 2: 24DA = (2) where: A = cross-sectional area of test specimen, mm2 (in.2); and D = diameter of test specimen, mm (in.). 2016 by the American Association of
19、 State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 323-5 AASHTO 8. REPORT 8.1. Sampling date and test date. 8.2. Failure PlaneIdentify if failure occurred at the interface, in the base concrete layer, or in the overlay concrete layer
20、. 8.3. Test Results: 8.3.1. Specimen Dimensionsincluding thickness of the overlay concrete, thickness of existing concrete, the diameter nearest 1.0 mm (0.05 in.), and the cross-sectional area nearest 1.0 mm2 (0.005 in.2). 8.3.2. Maximum load applied, nearest 10 N (2.0 lb). 8.3.3. Bond shear strengt
21、h, nearest 50 kPa (1.0 psi). 9. PRECISION AND BIAS 9.1. No precision and bias statements are available at this time. 10. KEYWORDS 10.1. Bonded layers; portland cement concrete; shear strength. 1Formerly AASHTO Provisional Standard TP 29. First published as a full standard in 2003. 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
