Control Tests for Concrete

Ch. 16

Project Specifications Characteristics of the mixture

Maximum size aggregate Minimum cement content

Characteristics of the cement, water aggregates and admixtures

Characteristics of the plastic and/or hardened concrete Temperature, slump, air content Compressive and/or flexural strength

Frequency of Testing FA Aggregate Moisture testing

Twice daily 1% change effects mix water requirement

by 13 pcy Slump Test

First batch of concrete delivered each day When consistency appears to vary Strength cylinders are made Temperature of concrete recorded

Con’t Air content tests

Initial batch of concrete When concrete test cylinders are

made Temperature of concrete recorded

Con’t Concrete strength testing for each class

of concrete placed Not less than once per day Not less than once for each 150 cy of

concrete placed Not less than once for each 5000 sq ft. of

surface area for slabs and walls. One 7-day, two 28-day cylinders are

required for each test and one or more “hold” specimens.

Moisture Content of Aggregates Oven dry method Microwave Moisture meter

Electrical resistivity

Plastic Concrete Sampling freshly mixed concrete

ASTM C 172 2 or more portions within a 15 minute window

Consistency Slump test – ASTM C 143

Test to be completed in 2 ½ minutes after obtaining sample

K-slump tester Kelly Ball Vebe consistometer

Con’t Temperature measurement

ASTM – C 1064 This test should be completed within 5

minutes after obtaining the sample Air content

ASTM C 231 – pressure method ASTM C 173 – volumetric method Test to be started within 5 minutes after

obtaining sample

Density and Yield ASTM C 138

Unit weight of plastic concrete Yield provides information concerning

volumetric quantity of concrete produced per batch

Y = total weight of components/unit weight

Time of setting ASTM C 403

Penetration resistance as a function of time

Initial set 500 psi (2-6 hours) Final set 4000 psi (4-12 hours)

Strength specimens ASTM C 31 –field molded specimens ASTM C 192 – laboratory specimens 6 x 12 for 1 inch or greater max size CA 4 x 8 for ¾-inch or less Beams are 6 x 6 x 30-inches Field specimens cured in same manner

as structure Lab specimens cured in sat. limewater

or moist room.

Destructive Testing of Hardened Concrete ASTM – C 39 for test cylinders

Strength effected by L/D ratio Condition of the ends of samples Sulfur mortar caps vs unbonded neoprene caps Loading rate (20-50 psi/sec)

ASTM C-78 for flexural strength using third point loading.

ASTM C-293 for flexural strength using center point loading.

Strength Tests of Hardened Concrete Compressive Strength Testing of Concrete,

ASTM C39 Unbonded neoprene caps, ASTM C1231

Flexural Strength - 3rd Point Method, ASTM C78

Flexural Strength - Center Point Loading, ASTM C293

Splitting Tensile Strength of Concrete. ASTM C496

fr = 7.5*(f’c)1/2

Failure Modes of Compression Testing

Flexure Strength Testing - Third Point Loading

Flexure Strength Testing - Center Point Loading

P

L = span

depth

Splitting Tensile Test

Air Content Petrographic Determination ofAir-

Void System, ASTM C457 hardened concrete air-void system void size and air-void distribution

system freeze/thaw durability

Density(Gs), Absorption and Voids

ASTM C642 Density or Unit Weight of Hardened

Concrete Absorption of Hardened Concrete Volume of Voids in Hardened

Concrete Density of Hardened Concrete by

Nuclear Density Gage

Other Tests Determination of Chloride Ion

Content in Hardened Concrete ASTM C1152 ASTM C1218

Volume and Length Change Shrinkage of Hardened Concrete

ASTM C157

Durability Frost Resistance

ASTM C666 Freezing in air and thawing in water Freezing in water and thawing in water Dynamic modulus of elasticity

Sulfate Resistance ASTM C1012

Corrosion Resistance ASTM C876 - Potentiometric Mapping

Corrosion Determination - Potentiometric Mapping

Con’t Abrasion Resistance

ASTM C779 ASTM C944 ASTM C1138 (underwater test)

Carbonation Phenolphthalein indicator method

Permeability ASTM C1202 “Rapid Chloride Permeability

Test

Nondestructive Test Methods

Rebound Hammer Tests Schmidt Hammer

http://www.corvib.com/concrete/schmidt.htm

NDTPenetration Testing

- Windsor Probe Maturity Testing

In-place Compressive Strength Pullout Tests

In-place Shear Strength

NDT Ultrasonic Pulse Velocity

Dynamic modulus of elasticity Cracking

Pulse Velocity Testing

NDT Other Dynamic Tests

Impact echo

Impact Echo Testing