Obtain Drill Cores & Sawed Beams of Concrete | ACI Level II – ASTM – C 42

Obtain Drill Cores & Sawed Beams of Concrete

ACI Level II – ASTM – C 42

Introduction

This test method provides standardized procedure for obtaining and testing specimens to determine the compressive, splitting tensile and flexural strength of in–place concrete

Generally test specimens are obtained when doubt exist concrete quality


General Sampling

Sample of hardened concrete for use in the preparation of strength test should not be removed before it is 14 days old

Sample that have been damaged during removal shall not be used unless the damaged portion are removed

Specimens containing embedded reinforcement shall not be used for determining compressive, splitting tensile & flexural strength

A core specimens shall be drilled perpendicular to the surface and not near formed joint


Measuring the Length of Drilled Cores

Cores for determining the thickness of pavement slabs, walls & other structural elements shall have diameter of at least 95mm

The lengths of such cores are stipulated to be measure in accordance with method C 174









Comments

Post a Comment

Popular posts from this blog

Air Content of Concrete by Volumetric Method (ASTM C - 173)

Image
 Air Content of Concrete by Volumetric Method ASTM C - 173 Introduction In this test, we will determine the air content in normal and heavy-weight concrete If the air content increases 1% above the design value  the strength reduction will be 3 to 5% Apparatus Air Meter, Bowl diameter equal to 1 to 1.25 times, Capacity of bowl 0.075 cubic feet, Top section 20% larger than a bowl Temping Rod,  Hemispherical tip, diameter 16 + 2 mm, height 100 mm greater than the bowl Isopropyl Alcohol, Calibrated Cup, Funnel, Rubber Syringe, Mallet, Procedure Dampen the bowl with water, fill the fresh concrete in the bowl with two equal layers First Layer, fill the half bowl of its volume, rodding 25 times through its depth, and distribute over the cross-section, 10 to 15 times tap with the mallet outside of the bowl Second Layer,  fill the remaining bowl, rodding 25 times to penetrate the previous layer about 25 mm, and distribute over the cross-section, 10 to 15 times tap with the...
Read more

Making and Curing of Concrete Cubes (BS EN-12390 Part 2)

Image
  Making and Curing Concrete Cubes  (BS EN-12390 Part 2) Introduction This standard specifies a method for making and curing test specimens for strength test Apparatus Cubes Molds = L 6 x W 6 x H6 Internal Vibrator = minimum frequency 120 Hz, diameter not exceeding one-quarter Vibration Table = minimum frequency 40 Hz Compacting Bar = having a square cross-section of approximately 25 by 25mm and a length of approximately 380mm Mallet Procedure Remix the sample before filling the cube molds Before filling the concrete, covered the mold's inner surface with a thin film of non-reactive release material  Specimen compacted minimum of two layers, but no layer more than 100 mm in thickness Mechanical vibration or hand compaction Mechanical Vibration Vibrate the concrete until the all entrapped air remove from the concrete and the depression left from the surface of a concrete over-vibration is the cause of segregation Hand Compaction The first layer, distribute the strokes in u...
Read more