Astm C 805

Introduction The direct determination of the strength of concrete implies that concrete specimens must be loaded to failure. Copyright Compu-tecture, Inc. The temperatures of the rebound hammer itself may affect the rebound number. Muhammad Khusnaini Asy Syadzili.

ASTM C Test Methods

Estimate the rebound number on the scale to the nearest whole number and record the rebound number. Data are not available on the relationship between rebound number and thickness of carbonated concrete.

These factors need to be ast in interpreting rebound numbers. Avoid areas exhibiting honeycombing, scaling, or high porosity. There were no books found for the applied search filters. The local curve for measuring strength of the regression method is set up and its superiority is proved.

The final results were compared with previous ones from the literature and also with actual results obtained from samples extracted from existing structures. The presence of surface carbonation can also result in higher rebound numbers. This x has been approved for use by agencies of the Department of Defense.

This procedure may result in the actual strength of concrete, but may cause trouble and delay in evaluating existing structures. Verication on the test anvil does not guarantee that the hammer will yield repeatable data at other points on the scale. At least two replicate cores shall be taken from at least six astm c with different rebound numbers.

ASTM C805 PDF DOWNLOAD

Remember me for one month. The relationship shall be established over the range of concrete strength that is of interest. Combining values from the two systems may result in non-conformance with the standard. Concrete should be tested only after it has thawed. Therefore, tests should be made with the same instrument in order to compare results.

An instrument guide is provided to center the rebound hammer over the impact area and keep the instrument perpen- dicular to the surface. Take ten readings from each test area.

ASTM C Test Methods

The manufacturer shall report the rebound number to be obtained by a properly operating instrument when tested on an anvil of specied hardness. Do not compare results from ground and unground surfaces. Are you sure you want to empty the cart?

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn. Site License Subscription. At least two replicate cores shall be taken from at least six locations with different rebound numbers. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use.

Standard Test Method for

The rebound method can be easily applied to concrete specimens as well as existing concrete structures. Some users compare several hammers on concrete or stone surfaces encompassing the usual range of rebound numbers encountered in the field. If you like to setup a quick demo, let us know at support madcad. The user should exercise professional judgment when testing carbonated concrete.

However, a successful nondestructive test is the one that can be applied to concrete structures in the field and be portable and easily operated with the least amount of cost. To use this test method to estimate strength, it is necessary to establish a relationship between strength and rebound number for a given concrete mixture and given apparatus. The user must exercise professional judgement when testing carbonated concrete. Current edition approved Nov. Smaller specimens must be rigidly supported.

ASTM C805 PDF

Troweled surfaces generally. Some users compare several hammers on concrete or stone surfaces encompassing the usual range of rebound numbers encoun- tered in the eld. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. If possible, test structural slabs from the underside to avoid nished surfaces.

The rebound method presented is simple, quick, and reliable and covers wide ranges of concrete strengths. Data are not available on the relationship between rebound number and thickness of cabonated concrete. This standard has been approved for use by agencies of the Department of Defense.

If possible, structural slabs should be tested from the underside to avoid finished surfaces. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ASTM C/M - Gilson Co

Areas exhibiting honeycombing, scaling, or high porosity should be avoided. Examine the impression made on the surface after impact, and if the impact crushes or breaks through a near-surface air void disregard the reading and take another reading. More From Bayron Medina Ospina. Historical Version s - view previous versions of standard. Some of these properties are hardness, rebound number, resistance to penetration or projectiles, resonance frequency, and ability to allow ultrasonic pulses to propagate through concrete.

Establish the relationship by correlating rebound numbers measured on the structure with the strengths of cores taken from corresponding locations. Gradually push the instrument toward the test surface until the hammer impacts.

Follow the manufacturers instructions for proper operation of such devices. Select test locations so that a wide range of rebound numbers in the structure is obtained. Among the available nondestructive methods, the rebound hammer is the most commonly used one in practice. Troweled surfaces generally exhibit higher rebound numbers than screeded or formed nishes. These factors need to be considered in interpreting rebound numbers.

Manger or Buyer or Director or Parcurment. Therefore, tests should be made with the same hammer in order to compare results.

It is the responsibility of the user of this standard to establish appropriate safety and health practices and astm c the applicability of regulatory limitations prior to use. These factors astm c to be considered in interpreting rebound numbers. Referenced Documents purchase separately The documents listed below are referenced within the subject astm c but are not provided as part of the standard. To estimate strength during construction, establish the relationship by performing rebound number tests on molded specimens and measuring the strength of the same or companion molded specimens. Therefore, the determination of concrete strength requires special specimens to be taken, shipped, marathi dj new songs and tested at laboratories.

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