The instantaneous deflection of twelve cracked normal and high strength concrete tbeams experimentally tested under two types of loading midspan and. Lab manual for deflection of beam experiment three handout. Specific testing required for the project will be found in the project specifications. For a complete description of the test, please refer to astm d2412. A static test is only static in that the load application comes to rest before the measurement is taken or the rate of deflection does not normally exceed 0. The deflection temperature is the temperature at which a test bar, loaded to the specified bending stress, deflects by 0. Torsional rigidity and beaming stiffness test procudure. Refer to table 1 in classification d4000, which lists the astm material standards that currently exist. In addition, a program of plate load testing made possible a correlation between plate load test data and. The three point bend test 1 beam theory the three point bend test figure 1 is a classical experiment in mechanics, used to measuretheyoung.
Vertical deflection criteria is the maximum vertical deflection ratio allowed for a lifting device. Beam deflection test data sheet for group i length 1 length 2 length 3 width mm height mm 4. The model 3540 deflectometer deflection gage measures small deflections in any orientation. Points are marked at only the outer wheel path in left side of the lane. Hibbeler, 7th edition, prentice hall structural analysis, hibbeler, 7th edition, prentice hall. Draw shear and moment diagram for the beam directly under the moment diagram draw a line for the beam and label all supports at the supports displacement is zero w hhere the moment is negative, the dfl ideflection curve is concave downward. Former deputy sheriff eddy craig right to travel traffic stop script washington state law duration. Correlation of flexible pavement rebound deflection development trendline with its curve pattern after the road life cycle limit i made sukartha 1, prof. Benkelman beam deflection measurements waka kotahi nz. This deflection is defined as a five percent reduction in the vertical base or average inside diameter. In effect, this suggested a test load weighing between 120 percent and 125 percent of the rated crane capacity i. Storm sewer is often tested after or during installation to ensure a sound installation was accomplished.
Unlike chladni testing or tap tuning which deal with the frequencies found in a plate, deflection testing instead measures the mechanical properties of the plate. Comparative studies between benkelman beam deflections. Deflection the deviation of the tip from the butt centerline after a known unit of force is applied to the tip to create a. Static and dynamic load deflection molded dimensions. Change is shape of the body is called deflection and change in the dimensions is called strain. Deflection method in displacement method,theunknown displacements are determined first by solving the structures equilibrium equations. Why is it necessary to compute deflections in structures. Data obtained by this test method shall not be used to predict the behavior of plastic materials at elevated temperatures except in applications in which the factors of time, temperature, method of loading, and fiber stress are similar to those specified in this test method. Astm d2412 is a testing standard used to determine the stiffness and load deflection of plastic pipe. Cantilever beam concentrated load p at any point 2 pa 2 e i lei 2 3for0 px yax xa 6 ei 2. A history of deflection testing transportation research board. The deflection of the channels was measured under the wheel path, midway between the 24 o. Testing deflection at low loads does not guarantee the safety of the crane and hence not practical. Beam deflection formulae beam type slope at free end deflection at any section in terms of x maximum deflection 1.
Stiffness method, which forms the basis of most computer software currentlyused for stt ltructural analilysis. This testing ensures that flexible pipe has been properly bedded and backfilled astm d2321 to give optimal performance. Deflection of beam theory at a glance for ies, gate, psu 5. This test method sets out the procedure for measuring the rebound deflection of a flexible pavement or road formation using a portable deflection. Deflectometer for 4point flex testing and component.
This method describes the procedure for the determination of rebound. Pavement evaluation and measurement of functional and structural. Standard test method for deflection temperature of plastics. Dynamic deflections for determining of flexible pavements. Standard guide for nondestructive testing of pavements. Beam diagrams and formulas table 323 continued shears, moments and deflections. Deflection method this method takes into account only the bending deformations. Before loading and keep the trolley at the centre provide a strain gauge or a vertical scale and pointer at the bottom of the. A vertical ring deflection greater than five percent 5% will not be allowed. The fwd trailer showing deflection bowl recorded at geophone offsets.
Quality assurance and deflection bowl field interpretation 21 4. This testing ensures that flexible pipe has been properly bedded and. Marking of the deflection observation points the deflection observations points are marked at transverse distance of 1. When uniform loads of 1,404 lb and 1,560 lb were applied, the 0. Compression load deflection testing american roller. Pavement deflection is measured by the benkelman beam which consists of a slender beam 3. Astm d2412 load deflection of plastic pipe test how to guide. If the deflection of a structure is more than the permissible, the structure will not look aesthetic and will cause psychological upsetting of the occupants. While the diversity of equipment and data applications make specific procedures infeasible, this guide is intended to encourage the collection of sufficient deflection data, adequate calibration of equipment, and implementation of general procedures leading to. Beam stress and deflection calculation two equal loads. Oct 30, 2011 former deputy sheriff eddy craig right to travel traffic stop script washington state law duration. Bb test load curve models of road deflection to obtain an idea of the strain that occurs in the pavement. Benkelman beam deflection studies linkedin slideshare. The axis of the beam deflects from its initial position under action.
Directreading dial indicator eliminates need for conversion tables or field calculations. The first deflection happens when the mold is clamped under full tonnage. Types of post installation field testing include deflection testing and joint testing. If any line were to not pass a mandrel, it is important to determine the cause. The benkelman beam measures the deflection of a flexible pavement under moving wheel loads.
Torsion test procedure step 1 reload the vehicle,as per step 1 of the beam test procedure. Request a quote nieltech provides independent mandrel deflection testing on all thermoplastic pipe sewers ranging in size from 6 up to 24 in diameter. Beam deflection test data sheet for group iii material no. This pavement analysis tool provides the following features. The value obtained for a specific polymer grade will depend on the base resin and on the presence of reinforcing agents. Deflection testing shall satisfy oepa requirements. This paper compares deflections measured during the four point bending test of the steel fiber reinforced, waste sand fine aggregate concrete. Standard guide for nondestructive testing of pavements using. Standard test procedure for benkelman beam deflection. The method of testing shall be subject to the a pproval of the engineer. Different types of test specimen and different constant loads are defined to suit different types of material. Variation of deflection with measuring equipment and load speed on test track recaredo romero, aurelio ruiz, ramon rodil, and miguel angel lechuga deflection is used on the fullscale test track to establish moduli for pavement layers and to provide useful information for strengthening studies and performance models. Tomore closely simulate a rolling truck tire, methods of dynamic deflection tests were sought, including falling bodies, the dynaflect and the the road rater.
Since 1935, a greater understanding of the value of deflection readings has developed. The reference axes have their origin at the fixed end of the beam. The deflection gauge is pulled through the pipe from mh to mh. A simple technique, based in a cantilever beam bending test, can be used in educational and training labs using generic laboratory equipment. California traveling deflectometer, as the rolling wheel load. Vertical deflection impacts any part of the crane that stands vertically, including the mast, columns, wall, etc. Benkelman beam evaluation of structural capacity of existing pavement estimation and design of over lay for strengthening of.
Deflection gauges mandrels are used to test flexible sewer pipe for outofroundness or deflection per astm specifications d3034 and f679. The mandrel deflection test must be performed after final backfill to road subgrade elevation has been placed. Able to analyze determinate beam deflection and slope by moment area method. Pavement evaluation by benkelman beam of state highway. This test procedure covers the determination of the rebound deflection of a pavement under a standard wheel load and tyre pressure, with or without temperature measurements. Noncontact deflection measurement at high speed greenwood. Vertical deflection differs from horizontal deflection, but both are taken into account for enclosed track bridge cranes. Purpose of platen deflection test plastics training. According to john case 1999 when a body is under stress, then that stress tries to change its shape and dimensions. Compression load deflection testing is one of the services we offer as part of our physical property tests. Selection of a test system a meeting was held november 10, 1975, in the office of materials laboratory for the purpose of deciding which dyna mic deflection. Determine the slope and deflection by using moment area method expected outcomes.
Deflection testing is a mechanical tuning process that is taken from techniques used by the violin masters. The normal net effect of aging is an increase in modulus or stiffness. Beam stress and deflection calculation two equal loads slideruleera structural 27 jan 16 00. Benkelman beam deflection studies transportation engineering section 2. Astm d2412 load deflection of plastic pipe test how to. This is useful in determing how a rubber covering will perform in a process condition. Deflection of steel fiber reinforced concrete beams based. Phd 3 civil engineering faculty, department of transportation, institute of technology sepuluh november, indonesia authors. There are three broad categories of nondestructive deflection testing equipment. Deflection should be find out by benkelman beam deflection test. Bearing capacity, noncontact, laser doppler, nondestructive test, measuring apparatus, deflection, structural condition, high speed. Each test compares a 4 inch section of reynolds 531 tube to a 4 inch section of reynolds 531 with an s and s bicycle torque coupling installed. Professional heat deflection temperature tester precise. Measurement methods have used either a rolling wheel or a simulated wheel load.
The beam and torsional deflection of the modified vehicle should increase approximately in proportion to the increase in wheelbase. By suitably placing the probe between the dual wheels of a loaded truck, it is possible to measure the rebound and residual deflections of the pavement structure. Deflection testing of earthwork and pavement layers. In each fixture a single load is applied to both test sections simultaneously so that the force is equal in both samples being compared. Comparative studies between benkelman beam deflections bbd. It should be used to find out the overlay thickness of the flexible over flexible pavement as per irc81 1997. It is important to understand that mandrel testing is a gonogo test. The magnitude of this change is dependent upon the specific material involved and the environmental conditions. Obstructions in the line, not associated with deflection, may influence the test. Keep the safe working load at the centre, by means of concrete blocks or steel.
Factors affecting static and dynamic load deflection characteristics age the aging of rubber compounds over a period of time is a complex process. Variation of deflection with measuring equipment and load. Experimental protocol for cantilever beam bending test several methods may be used to determine the young modulus and poisson ratio of a material 1. This test method evaluates the tensile behaviour of steel fibrereinforced concrete either in terms of areas under the loaddeflection curve or by the load bearing. Test results are recorded electronically and the whole setup is usually mounted on a trailer towed behind a specially equipped vehicle. Such a test usually places the rubber in shear or compression. Visual inspection is recommended in the event of a nogo result. The platen deflection test is used to determine the amount of stationary platen deflection that occurs during the molding cycle. Deflection testing of earthwork and pavement layers roads and. Test method t160 deflection measurement portable beam. Existing highway pavements structural details by test pit. Following is the equation which can be used for calculating deflection in beams.
Experimental protocol for cantilever beam bending test. Understanding overhead crane deflection and criteria spanco. The installation completed fourteen cycles with no evidence of damage to the tiles or grout joints. Due to improper experimental setup, the actual results experienced varied substantially when compared. Computation of deflection of structures is necessary for the following reasons.
Since the early 1960s, caltrans research data have been based on deflections obtained by using the. Collection and interpretation of pavement structural. These tests demonstrate that in torsion, tension and bending, a tube that has an s and s bicycle torque coupling installed will be stiffer than a plain section of reynolds 531 bicycle tube. Under the action of the load, the axis of the beam deforms into a curve. This heat deflection temperature tester is designed and engineered offering the newest microchip technology to ensure high accuracy and real time test monitoring, a precision heating and cooling system, a precision deflection measurement system, a large sample area to test up to three sample simultaneously, a large color lcd display for. The reasons for measuring pavement deflection are outlined. Also soil sample is taken at the site through at the pavement composition survey locations. This summary is intended to help you understand the basic procedure and equipment required to complete this test with accuracy.
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