Pavement deflection is measured by the benkelman beam which consists of a slender beam 3. Benkelman beam deflection measurements waka kotahi nz. The benkelman beam is used with a loaded truck typically 80 kn 18,000 lb on a single axle with dual tires inflated to 480 to 550 kpa 70 to 80 psi. Velciti done benkelman beam deflection for various state and cities roads and highways. Comparative studies between benkelman beam deflections. It measures deflection of flexible pavements under the action of moving wheel loads. Adjustable feet for benkelman beam, complete with two spirit level calibration device 80b01803 calibration device for 80b0180 benkelman beam apparatus. Cetanz proficiency test report test method tnz t1 1977. Benkelman beam yang menunjukkan kelainankelainan di luar batas toleransi, perlu diperbaiki sampai batas toleransi tersebut dipenuhi. This test procedure covers the determination of the rebound deflection of a pavement under a standard wheel load and tyre pressure. The beam test shall be as per nzta specification t1 except that the recordings for bowl deflection shall not be recorded or used in the deflection calculation. Aashto t 25601, standard method of test for pavement deflection measurement 3 istilah dan definisi istilah dan definisi yang digunakan dalam standar ini sebagai berikut. The entire apparatus, must be sturdy, rigid and without slop. Nine laboratories took part in the benkelman beam proficiency test.
This enables point testing at userspecified locations in the outer andor inner wheel paths. Supplied complete with a wooden transport case 430mm x 1800mm x 350mm. Introduction the benkelman beam instrument is used to measure the deflection of the road. Pavements analyzed and test locations are shown in the figure 1. It is not necessary for the tyres to be of any standard pattern. Benkelman beam myers pavement quality testing equipment. We have unique approach in our business which providing. Benkelman beam kit with bearing plate to nf p982002 consisting of. Comparative studies between benkelman beam deflections bbd. Benkelman beam deflection studies linkedin slideshare.
Lwd test lwd was taken to the identified locations and tests were carried out. Overlay design by benkelman beam road surface standard. Standard guide for general pavement deflection measurements. It should be used to find out the overlay thickness of the flexible over flexible pavement as per irc81 1997. Lwd and benkelman beam tests were carried out on these pavements inside the campus. To verify the correct performance of the apparatus. T256standard method of test for pavement deflection measurements. Standard test procedure for benkelman beam deflection. Place a probe beam between the tires of a test vehicle. E benkelman beam a benkelman beam is shown in figure 2. Telescoping design for easy set up and reduced storage space requirements. You can see our benkelman beam deflection testing works below, about us.
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. Standard guide for nondestructive testing of pavements. Deflectometer rdd, benkelman beam deflectometer bbd. You can see our benkelman beam deflection testing works below. The benkelman portable beam apparatus is a convenient, cost effective and accurate device used for measuring the deflection of flexible. The benkelman beam measures the deflection of a flexible pavement under moving wheel loads. A comparative subgrade moduli study is carried out by static and dynamic deflection methods using lightweight deflectometer and conventional benkelman beam deflectometer on low volume road.
The equations express the pavement deflection as functions of wheel load, vehicle speed and pavement temperature. Field and laboratory tests are performed at 40 test locations on inservice road of 2 km stretch that contains three common types of cohesive soils ch, ci. Strength evaluation of flexible pavement of runway using. Deflection is measured when the vehicle passes over the test area.
Pdf comparative studies of lightweight deflectometer and. Our team is your onestopshop for pavement testing, ensuring you get the data you require. Benkelman beam apparatus, asphaltbituminous mixture testing. Specifications for measurement condition survey and deflection data are used to establish sections of uniform performance. The probe beam, supported by a rigid reference beam, measures deflections using its 2. Comparison of static modulus by benkelman beam bb test and dynamic modulus by lightweight deflectometer test were conducted by guzzarlapudi, et al. Benkelman beam adalah revisi dari sni 0324161991,metode pengujian lendutan perkerasan lentur alat benkelman beam.
The benkelman beam figure 2, developed at the western association of state highway organizations washo road test in 1952, is a simple device that operates on the lever arm principle. Dimensions a and b must be recorded on form bb1 for each beam together with the benkelman beam no. Cetanz proficiency test report test method tnz t1 1977 benkelman beam test dear cetanz member, please find attached the results from the benkelman proficiency testing organised by cetanz in may 2008. Whenever new pavement is to be laid this reading is helpful. Comparative studies of lightweight deflectometer and. Pavement evaluation by benkelman beam of state highway. Secara umum penyiapan alat benkelman beam sebelum penyetelan adalah sebagai berikut. Cara uji lendutan perkerasan lentur dengan alat benkelman beam. Deflection should be find out by benkelman beam deflection test. This pavement analysis tool provides the following features. Comparison study of overlay design for engineering. Specifications for measurement condition survey and deflection data are used to establish sections of uniform performance at least 10 deflection measurements should be made for each section per lane subject to a minimum of 20 measurements per km.
The bbd technique is a popular test all over the world for estimating the required overlay thickness. Most of the road network in india has a significant level of deterioration and therefore requires major rehabilitation projects. Development correlation between benkelman beam deflection. Benkelman beam deflection testing company india, tamilnadu. The amount of rebound deflection can be determined by the formula 3 below. Fhwahrt16011 december 2017 research, development, and technology turnerfairbank highway research center 6300 georgetown pike mclean, va 221012296. Using fwd data with me design and analysis, volume iii. The beam pivot bearing and the dial gauge must move freely without friction or slop. Benkelman beam bb devices should be corrected by a factor of ground water table seasonal factors and temperature correction and a correction factor of the load test if not exact test load of 8. The system combines a linear displacement electronic transducer, wireless pda, global positioning system gps and simple to use software to produce faster, more accurate, and less labour intensive measurement and reporting of road pavement.
Since there is a not much of the heavy traffic inside the campus, pavements are assumed to carry light traffic. Benkelman beam apparatus, asphaltbituminous mixture. Pdf comparative studies between benkelman beam deflections. Paper open access related content road maintenance.
Velciti pvt ltd is the leading getech and highway consultant company in india. This test method sets out the procedure for measuring the rebound deflection of a flexible pavement or road formation using a portable deflection beam under both a standard wheel load and tyre pressure. 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. The space between the tyres must be wide enough that the benkelman beam can be placed between the tyres without touching them. The following survey and tests will be conduct to compare deflection of flexible pavements by bbd and fwd techniques. All the procedure for conducting benkelman beam deflection test were followed as per the guidelines given in irc.
In this study attempt has been made to conduct this test on the top of conventional whitetopping. Development correlation between benkelman beam deflection and. Sep 25, 2016 comparison of static modulus by benkelman beam bb test and dynamic modulus by lightweight deflectometer test were conducted by guzzarlapudi, et al. Collection and interpretation of pavement structural.
Oct 08, 2016 bankelman beam deflection test duration. 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. Directreading dial indicator eliminates need for conversion tables or field calculations. Benkelman beam evaluation of structural capacity of existing pavement estimation and design of over lay for strengthening of weak pavement 5. Benkelman beam deflection measurements 5 pages, 40 kb. Iri value, deflections and traffic growth gained from years 20112015 subsequently created regression models to obtain the relationship and the correlation coefficient. Studies of pavement deflection measured with the benkelman beam were carried out at the aasho road test, ottawa, 111.
The most widely used method in india has been benkelman beam deflection bbd method. Pddx pavement deflection data exchangetechnical data guide, version 1. Cara uji lendutan perkerasan lentur dengan alat benkelman. The beam is placed in contact with the surface under test between the vehicle tyres. Lightweight aluminum construction for easy transport to test site locations. Penyetelan alat benkelman beam dengan alat penyetel ditujukan untuk mengetahui batas toleransi ketelitian alat. Guidelines for deflection testing, analysis, and interpretation publication no.
The vehicle passes over the test area to beyond the end of the probe beam determines deflection measurement. Pavement evaluation and measurement of functional and structural. We also provide inhouse traffic management so you dont have to, allowing you to focus on your projects, while we get the testing done. Test data are summarized by means of tables, graphs and mathematical equations. The dial indicator is not included and must be purchased separately. The shamrock wireless electronic benkelman beam is an automated system for measurement and reporting of road pavement deflection. Iri, pavement condition assessment functionally with deflection method using test data tool benkelman beam bb and the actual traffic load. General a the surface under the beam shall be sound and free of excessive loose material, large protruding. The lwd is a portable device that applies the same type of stress pulse acting on a 300 mm diameter. The deflectograph is, in essence, a pair of automated benkelman beams mounted under a truck. The hm574 benkelman beam is a simple leverarm device which measures deflection of flexible pavements under the action of moving wheel loads. Referenced documents purchase separately the documents listed below are referenced within the subject standard but are not provided as part of the standard aashto standard. Standard guide for nondestructive testing of pavements using.
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