AASHTO TP 84-2011 Standard Method of Test for Evaluation of Adhesive Anchors in Concrete under Sustained Loading Conditions.pdf

1、Standard Method of Test for Evaluation of Adhesive Anchors in Concrete under Sustained Loading Conditions AASHTO Designation: TP 84-11 (2016)1 Release: Group 2 (June 2016) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 200

2、01 TS-4c TP 84-1 AASHTO Standard Method of Test for Evaluation of Adhesive Anchors in Concrete under Sustained Loading Conditions AASHTO Designation: TP 84-11 (2016)1Release: Group 2 (June 2016) INTRODUCTION Adhesive anchor systems have widespread use in transportation structures such as bridge wide

3、ning, concrete repair and rehabilitation, barrier retrofitting, utility installation on existing structures, and tunneling. These systems are used to anchor threaded rod and reinforcing bars in concrete. This test method determines an adhesive anchors ability to withstand sustained tensile loads und

4、er normal conditions. 1. SCOPE 1.1. This test method applies to structures used in AASHTO applications and is applicable to adhesive anchor systems with steel anchors in predrilled holes in concrete. 1.2. This test method determines the time to failure for adhesive anchors in concrete at various lev

5、els of sustained loading. 1.3. The static load test is developed from ASTM E488 and the sustained load (creep) test is modified from ASTM E1512 and ICC-ES AC308. 1.4. This test method only addresses the effect of sustained loads on adhesive anchors. Numerous other factors affect the load capacity of

6、 adhesive anchors and a complete battery of tests is essential to evaluate an adhesive anchor. Refer to ICC-ES AC308 for a listing of some of the many factors and related test methods that apply to adhesive anchors. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: T 22, Compressive Strength of Cylindr

7、ical Concrete Specimens T 23, Making and Curing Concrete Test Specimens in the Field T 24M/T 24, Obtaining and Testing Drilled Cores and Sawed Beams of Concrete 2.2. ASTM Standards: A193/A193M, Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure S

8、ervice and Other Special Purpose Applications D907, Standard Terminology of Adhesives E488/E488M, Standard Test Methods for Strength of Anchors in Concrete Elements E1512, Standard Test Methods for Testing Bond Performance of Bonded Anchors 2016 by the American Association of State Highway and Trans

9、portation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4c TP 84-2 AASHTO 2.3. International Code Council Standard: ICC-ES AC308, Acceptance Criteria for Post-Installed Adhesive Anchors in Concrete Elements 3. TERMINOLOGY 3.1. Refer to ASTM D907 for a complete listi

10、ng of terminology related to adhesives. 3.2. Definitions of Terms Specific to This Standard: 3.2.1. adhesive anchora post-installed anchor that tr ansfers load to concrete through an adhesive compound embedded in a hole in hardened concrete. The adhesive materials used include epoxy, cementitious ma

11、terial, polyester resin, and others. 3.2.2. adhesive anchor systemfor the purposes of this standard, the adhesive anchor system is composed of the following components: adhesive anchor; proprietary adhesive compounds in combination with a mixing and delivery system; accessories for cleaning the dril

12、led hole, such as wire brushes, air nozzles, etc.; and printed instructions for the adhesive anchor installation, including hole preparation, injection, and cure. 3.2.3. creepthe deformation or displacement of an adhesive over time due t o stress. 3.2.4. embedment depthdistance from the surface of t

13、h e structural member to the end of the installed anchor. 3.2.5. linear variable differential transformer (LVDT)an electronic instrumentation device used for measuring displacement. 3.2.6. static load testa test in which a load is slowl y applied at a specified rate for one cycle until failure. 3.2.

14、7. sustained load (creep) testa test in which a constant lo ad is continuously applied until failure due to creep. 3.2.8. test specimenthe structural member, anchor rod, and adhesive. 3.2.9. Symbols: d = nominal anchor diameter, in. (mm) do= nominal diameter of drilled hole in concrete, in. (mm) f c

15、 specified compressive strength of concrete, psi (MPa) hef= effective depth of embedment of an anchor, in. (mm) 4. SIGNIFICANCE AND USE 4.1. This test method provides a means of: 4.1.1. Determining the mean static load of an adhesive anchor, 4.1.2. Determining acceptable loads to apply to an adhesi

16、ve anchor based on the lifetime of the structure, and 4.1.3. Determining an adhesive anchors ability to endure sustained loads. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4c TP 84-3 AASHTO 4.2.

17、The stress versus time-to-failure graph is useful to the practicing engineer in selecting and designing adhesive anchors. 4.3. A stress versus time-to-failure graph can give an indication of the reduction in capacity of an adhesive anchor due to sustained load at a given design lifetime. 4.4. This t

18、est method provides a means for comparing adhesive anchor products for sustained loading applications. 4.5. The test methods in this standard should be followed in order to ensure reproducibility of test results. 5. TEST APPARATUS 5.1. Instrumentation and Data Collection: 5.1.1. All laboratory instr

19、umentation (electronic load, displacement, temperature, and humidity sensors, etc.) must be calibrated with certified equipment. 5.1.2. A load cell or other load-measuring device must be able to measure forces to within 1 percent of the anticipated peak load. 5.1.3. As an alternative, a load cell is

20、 not required for monitoring the sustained load (creep) test if the test apparatus has a stiffness that is sufficiently low to ensure accuracy of 1 percent of the applied sustained load at the maximum anchor creep displacement and if a stiffness-displacement relationship can be established to determ

21、ine the load applied with reasonable confidence. 5.1.4. Displacements should be measured continuously by LVDTs, linear potentiometers, or an equivalent device with an accuracy of at least 0.001 in. (0.025 mm). 5.1.5. The instrumentation must be placed in a way that does not interfere with the anchor

22、 or testing apparatus. The instrumentation should measure the vertical displacement and load on the anchor relative to the test specimen. The instrumentation should be placed in such a way that it will remain parallel to the axis of the anchor and will not be affected by the deflection or failure, o

23、r both, of the anchor or test specimen. 5.1.6. Two displacement measuring devices shall be placed equidistant and sufficiently far away from the anchor to not be within the potential failure surface. The two displacement values shall be averaged to obtain the actual displacement. One displacement me

24、asuring device may be used if it is placed centered on the anchors axis and can be shown to produce acceptable confidence. 5.1.7. Static Load TestThe measuring devices and the data collection system must be a ble to gather data points at least twice per second for the static load test. 5.1.8. Sustai

25、ned Load (Creep) TestThe measuring devices and the data collection system must be able to gather data points according to a progressively reducing frequency as discussed in Section 9.4.6.2 and Note 4. 5.2. Test Apparatus: 5.2.1. Examples of suitable test apparatus for static and sustained load (cree

26、p) tests are shown in Figures 1 and 2, respectively. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4c TP 84-4 AASHTO Source: Modified from Cook et al. Section 14.2. Figure 1Static Load Test Apparat

27、us Source: Modified from Cook et al. Section 14.2. Figure 2Sustained Load (Creep) Test Apparatus 5.2.2. The test apparatus must be of sufficient capacity so as to not yield during testing. 5.2.3. CouplerA coupler shall be used between the anchor and the test loadin g rod, providing a nonrigid connec

28、tion that does not transfer bending forces. LinearPotentiometer(2 each)Loading RodRetaining NutsCompressionLoad CellHydraulic RamNon-RigidCouplerConfiningPlateConfiningSheetAnchorLoad FrameFront View Side ViewLoad Frame (below)Corner Bolts (4)Corner Bolts (4)Coupling RodLoading RodRetaining NutsWash

29、ers 11.1.2. Test sponsor and test agency; 11.1.3. Anchor InformationManufacturer, model, type, material, finish, shape, dimensions , and other relevant information; 11.1.4. Adhesive InformationManufacturer, model, type, lot, material, application method, and other relevant information; 11.1.5. Struc

30、tural Member InformationDescription, dimensions, reinforcing, mix design of concrete, aggregate type, curing method, concrete strength at time of test, age of concrete at time of test; 11.1.6. Installation InformationDescription of the procedure, tools, and methods used to insta ll the adhesive anch

31、or. Include the drilling and cleaning of the holes as well as the installation of the adhesive and anchor. Document any deviations from the manufacturers specifications; 11.1.7. Adhesive Curing InformationTemperature and humidity conditions, duration of cure, time wh en conditioning of test specimen

32、 began; 11.1.8. Temperature and humidity conditions at time of installation and during adhesive cure, conditioning, and final testing; 11.1.9. Embedment depth and diameter of hole of installed anchors; 11.1.10. Test InformationDescription of test method, am ount of initial load, and actual rate of l

33、oading; and 11.1.11. Number of samples tested per series. 11.1.12. Static Load Test Data: 11.1.12.1. Individual and average load values per anchor and coefficient of variation, 11.1.12.2. Individual and average displacement values at maximum load, 11.1.12.3. Load-versus-displacement curves per ancho

34、r, and 11.1.12.4. Load-versus-time curves per anchor. 11.1.13. Sustained Load (Creep) Test Data: 11.1.13.1. Individual time-to-failure values per anchor, 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.

35、TS-4c TP 84-11 AASHTO 11.1.13.2. Individual load values and percent mean static load values at failure per anchor, 11.1.13.3. Individual displacement values at failure per anchor, 11.1.13.4. Load-versus-displacement curves per anchor, 11.1.13.5. Displacement-versus-time curves per anchor, 11.1.13.6.

36、 Load-versus-time curves per anchor, and 11.1.13.7. Stress versus time-to-failure curve; 11.1.14. Photographs, sketches and descriptions of failure modes observed; 11.1.15. Summary of findings; and 11.1.16. Listing of observers of tests and signatures of responsible persons. 12. PRECISION AND BIAS 1

37、2.1. PrecisionNo precision has been established for this test method. 12.2. BiasNo bias can be established because no reference material is av ailable for this test. 13. KEYWORDS 13.1. Adhesive anchors; anchors; bonded anchors; creep test; concrete; post-installed anchors; static load test; sustaine

38、d load test; test methods; time-to-failure test. 14. REFERENCES 14.1. Cook, R. A., and R. C. Konz. Factors Influencing Bond Strength of Adhesive Anchors. ACI Structural Journal, Vol. 98, No. 1. American Concrete Institute, Farmington Hills, MI, 2001, pp. 7686. 14.2. Cook, R. A., R. C. Konz, and D. S

39、 Richardson. Specifications for Adhesive-Bonded Anchors and Dowels. Report No. 96-3. University of Florida, Gainesville, FL, 1996. APPENDIXES (Nonmandatory Information) X1. INCREMENTAL LOAD RATE X1.1. The incremental load rate is a method that applies the load in several load steps, holds the load

40、for 2 min, and then increases to the next load level. Apply the load in steps with the first increment not greater than 50 percent of the estimated ultimate load and each increment thereafter not exceeding 15 percent of the estimated ultimate load. Maintain each load increment within a tolerance of

41、3 percent for 2 min. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4c TP 84-12 AASHTO X1.2. This method can provide an indication of an adhesives sensitivity to sustained loading at higher load lev

42、els. X1.3. Figure X1.1 shows a load-versus-displacement curve and a time-versus-displacement curve for an anchor under incremental loading. Figure X1.1Load-Displacement and Time-Disp lacement Curves with Incremental Loading X1.4. As shown in Figure X1.1, as the load is held constant, the anchor in t

43、his graph displays more displacement at the higher load steps. X1.5. Figure X1.1 also shows that, at the lower load levels, the displacement tends to stabilize. Additionally, at the higher load levels, the anchor continues to displace. This is indicated by the slope of the time-displacement curve. X

44、2. DETERMINING STATIC LOAD STRENGTH X2.1. Cook and Konz Section 14.1 classify three types of load-displacement response (strength-controlled, stiffness-controlled, and displacement-controlled) for adhesive anchor systems. These three types of responses and methods of their analysis are summarized be

45、low: X2.1.1. Strength-ControlledThis failure mode is defined by a very sharp peak in the load- displacement curve. There is a drastic reduction in the stiffness of the adhesive anchor beyond the peak. The static load strength is determined to be at the peak on the load-displacement graph. Figure X2.

46、1 shows a typical curve of a strength-controlled failure. 010020030040050060070080090010002,0004,0006,0008,00010,00012,00014,00016,00018,00020,0000.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100Time(s)Load(lbf)Displacement (in.)LoadTime0 2016 by the American Association of State Hig

47、hway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-4c TP 84-13 AASHTO Source: Cook and Konz Section 14.1; reprinted with permission of ACI. Figure X2.1Typical Strength-Controlled Failure X2.1.2. Stiffness-ControlledThis failure mode is defined by

48、a large initial stiffness and a drastic change in stiffness that does not decrease, but rather continues to increase at a lower slope. Due to the lack of “peak” in the curve, the static load strength is determined by finding the point at a tangent stiffness of 30 kip/in. (5 kN/mm). The tangent stiff

49、ness (slope) at a given data point can be approximated by calculating the slope between a point five data points after and five data points before. Figure X2.2 shows a typical curve of a stiffness-controlled failure. Source: Cook and Konz Section 14.1, reprinted with permission of ACI. Figure X2.2Typical Stiffness-Controlled Failure 16014012010080604020001234130.8Displacement, mmTensileLoad, kN1601401201008060402000 1234101.6Displacement, mmTensile Load, kN 2016 by the American Association of State Highway and Tra