As described above, one of the critical aspects of durability of concrete repairs and overlays is a lasting and. Earlier this year we took a look at the development of selfhealing concrete that repairs its own cracks using a builtin healing agent. Experiments were carried out to study the effect of workmanship and environmental conditions on bond strength for concrete patch repairs. Concrete bond strength testers, anchor testers, pulloff. This is a useful test when used to evaluate air barrier. Tensile bond strength of a high performance concrete. Pull off adhesion testers for concrete strength testing proceq. A number of tests have been used to determine the following properties of repair materials. This test method is not appropriate for determining the pulloff strength of the frp from the patch material. The bondtest is used to conduct a pulloff test in accordance with astm c1583, test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method. Best practices for preparing concrete surfaces prior to.
Evaluation of bond strength between overlay and substrate. Four repair materials, sandcement mortar, acrylic modified cementitious mortar, sbr modified cementitious mortar, and flowing concrete, were tested with mainly three test methods core pulloff test, patch compressive test, and patch flexural test. Featuring a unique gray color, hp concrete is designed to perform extremely. Great for repair techs who routinely repair ipads and need to diagnose a. Field applications of insitu tensile pulloff tests to evaluate bond of concrete surface materials by. Tensile bond strength of a high performance concrete bridge deck overlay. Pull off adhesion testers for concrete strength testing.
Reduce wear and tear on the delicate connectors on your ipad with this tester cable. Substrate should be saturated surface dry ssd with clean water prior to application. Astm c1583 c1583m standard test method for tensile. To ensure optimum repair results, the effectiveness of decontamination and preparation should be assessed by a tensile adhesion strength pulloff test. These methods are used in completing the field condition survey of buildings. The development and maintenance of a sound band is an essential requirement of a concrete patch repair.
This paper discusses the main issues relevant to tensile bond testing, namely material properties, surface. Such testing follows astm c 1583, standard test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method. To evaluate the inplace bond strength between a repair overlay and. This tester can be used to determine the need for surface preparation, detect relative differences in potential surface strength over an area to be repaired, and determine the adequacy. The compressive strength can be considered as proportional to the ultimate pullout force. Pull off test to evaluate the compressive strength of. Strength of concrete repair and overlay materials by direct tension. The quality of concrete repairs is determined by the adhesive strength between the repair material and the substrate. Astm d4541 standard test method for pulloff strength of.
Utc3250 digital bond strenght pull off tester standards. The most common method of nondestructive field testing is through a process called sounding. Engineers, researchers, and contractors are devoting considerable effort towards improving the durability of concrete repairs. Field guide to concrete repair application procedures. To ensure that the surface preparation procedures were followed as per the specifications, the pulloff strength of the prepared surface prior to repair application is measured. Although the sand patch test14,25and the profilometric method44,65are still popular for evaluating the surface morphology of concrete, tayeh et al. In recent years, the pulloff test method has gained favour as an in situ. The test determines the greatest perpendicular force in tension that a surface area can bear before a plug of material is detached. The requirements for pulloff adhesion of concrete repair and historic stone repair are different, since for.
Crafco hp concrete cold patch offers a quick, easy, and quality solution for both sides of the pavement universe. Field testing of concrete structures include nondestructive testing and destructive testing. The bondtest is used to conduct a pulloff test in accordance with astm c1583, test method for tensile strength of concrete surfaces and the bond strength or. Measurement of bond strength by pulloff is classified in these ics categories. Recorded parameters include the timedate of the test, test disc size, maximum load applied, calculation of bond strength, applied load rate, test. Pulloff adhesion strength testing of lining systems on concrete. The tensile pulloff adhesion test of the existing concrete should be conducted as part of the condition evaluation report. In this same regard, repairs to concrete structures need to be as long lasting as possible. This thesis was aimed at studying the evaluation of bond strength between repair material and substrate at the interface.
Digital bond strenght pulloff tester protection and. Destructive and nondestructive field testing of concrete. E j buckton, h j fereday, s r banks, g a maunsell, h j nichols, p l pratley, h shirley smith and h s smith. Many factors such as surface roughness, existence of micro cracks, compaction, curing etc influence the bond. Tensile bond tests are increasing in popularity as a means of measuring this adhesive property, both on site for quality control and in the laboratory for materials evaluation. References direct tensile pulloff testing astm standard 1583 standard test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method icri guideline 210. The proceq dy2 family of automated pulloff testers covers the complete range of pulloff applications with unmatched ease of operation and the. The counterpre s s u r e ring of the testing machine is placed against the surface of the concrete and load is hyd r aulically applied by turning the handle of the testing m a c h i n e. The pulloff strength determined by this procedure is a performance property, and it may be referenced in specifications. Astm d454117 pulloff strength of coatings test ansi blog.
In the test, the traction is axially transmitted to the disc previously bonded to the concrete. Proceedings of the institution of civil engineers structures and buildings. The pull off test is based on the concept that the traction force required to pull a metallic disc bonded to a surface layer of concrete is associated with the compressive strength of the material 19. Proceedings of the institution of civil engineers structures and buildings, volume 110, issue 4, 1 nov 1995 3560. Astm c1583 c1583m, standard test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method, astm international, west conshohocken, pa, 20, back to top. Tensile bond testing of concrete repairs springerlink. The bondtest is used to conduct a pulloff test in accordance with. Using this type of testing for quality assurance ensures that clients receive an adequate, wellconstructed repair. The tensile bond strength pulloff test is a quick, and simple method for determining how well repair material or an overlay is bonded to underlying concrete. Reliability of the pulloff test for in situ evaluation of. An additional test method is required to determine the pulloff strength of the patch from the substrate concrete. Repair to concrete structures often involves breaking out cracked concrete and replacing this and areas of spalling with a mortar or concrete. Astm d4541 standard test method for pulloff strength of coatings using portable adhesion testers.
Astm c1583c1583m 20 standard test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method astm c1600c1600m 2017 standard specification for rapid hardening hydraulic cement astm c1602c1602m 2018 standard specification for mixing. Concrete pulloff testing is used to confirm the substrate strength prior to the installation of repair materials or as quality assurance for the installation of overlays or fiber wrap. The bond test is used to conduct a pulloff test in accordance with astm c1583, test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair. Astm d4541 is a standard test method that is used in order to evaluate the pulloff strength of air barrier membranes. The pulloff test as a means of projecting the compressive strength of concrete and other materials involves bonding a circular steel disk to the surface by means of an epoxy resin adhesive. This is again often referred to as cohesive failure of. Reliability of the pulloff test for in situ evaluation of adhesion strength. Read on for information on repairing small cracks, sidewalks, and driveways, as well as patching holes and corners. Failure will occur along the weakest plane within the system comprised of the test fixture, adhesive. When the time comes to repair concrete, you need to have a sound understanding of exactly how to patch it since it will not only save you time but also save you a great deal of money and effort. Adhesion of the new patch to the original concrete is generally considered to be an important criterion in judging the success of the repair.
Pulloff adhesion strength testing of lining systems on. Astmd7522 standard test method for pulloff strength. The proceq dy2 family of automated pulloff testers covers the complete range of pulloff applications with unmatched ease of operation and the ability to store a complete record of the test. Saw cutting perimeter edges of concrete repair area at a dovetail is preferred. The standard test method covered in astm d454117 standard test method for pulloff strength of coatings using portable adhesion testers is used for evaluating the pulloff strength otherwise known as adhesion of a coating system from metal substrates. The testers provide a complete record of the pulloff test, confirming that the test was carried out in accordance with the applicable standard. Pullout tests on hardened concrete the constructor. D2651 guide for preparation of metal surfaces for adhesive bonding. C1583 test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension pulloff method d16 terminology for paint, related coatings, materials, and applications. Applicable to products and systems applied to a thickness up to 50 mm.
A controlled tensile force is then applied to the disk, and as the strength of the bond becomes greater than that of the material under stress it will eventually fail in tension. Pulloff testing is the most widely used test method to assess bond strength. The american concrete institute aci however, has presented a test. The guide outlines equipment and material requirements, the test procedure, reporting, and acceptance. Good bond strength between overlay and substrate is a key factor in performance of concrete repairs. Bond characterization between concrete substrate and. Repair and overlay materials by direct tension pulloff.
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