Aggregate Effects on Pervious Portland Cement Concrete Static Modulus of Elasticity

The seismic testing technique was combined with the maturity concept to monitor and predict the strength gain of portland cement concrete. In this process, the dynamic modulus of elasticity of a given mixture, obtained from its stress wave velocity, can be related to the strength parameters and static modulus of the mixture by using the same specimens used in the calibration process commonly carried out for maturity tests. When these relationships are combined with the maturity parameters, the predictive power is significantly improved. In this investigation, laboratory tests with molded specimens and cores were carried out by the simplified free–free resonant column method, and field tests of concrete slabs were performed with a handheld device called the portable seismic pavement analyzer. On the basis of the results of these experiments, relationships between the dynamic modulus and the strength parameters as well as the maturity are proposed. The technique was shown to be a rapid, simple, and economical means for optimization of concrete mix design, quality control–quality assurance of concrete construction, and determination of the time required before a repaired or newly constructed structure is ready for use.

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Comprehensive Quality Control of Portland Cement Concrete With Seismic Methods

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1575-14 ◽

1997 ◽

Vol 1575 (1) ◽

pp. 102-111 ◽

Cited By ~ 1

Author(s):

Soheil Nazarian ◽

Deren Yuan ◽

Eric Weissinger ◽

Mark McDaniel

Keyword(s):

Quality Control ◽

Portland Cement ◽

Field Tests ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Field Methods ◽

Static Modulus ◽

Seismic Methods ◽

Coefficients Of Variation ◽

Seismic Tests

The feasibility of seismic methods for determining the quality and thickness of portland cement concrete layers was recently studied. The study consisted of performing nondestructive laboratory seismic tests on cylinders that were laboratory-cured for 2 to 90 days. The cylinders were then subjected to appropriate strength tests (such as compressive and splitting tensile). Reasonably high correlations were found between static modulus, compressive strength, or tensile strength and seismic modulus. Seismic moduli were also found to be repeatable, as the coefficients of variation for different lots were generally less than 2 percent. Similar tests were also performed on cores retrieved from a site constructed with similar concrete. Before coring the slabs, nondestructive seismic tests were also performed on the concrete. Seismic moduli from laboratory and field tests were close and repeatable. The coefficients of variation for the seismic tests were generally less than 3 percent and 4 percent for the laboratory and field tests, respectively. The curing patterns observed in both the field and the laboratory were very different. Regardless of the methodology used, the correlations based on the laboratory specimens appear not to be representative of the field behavior. A focus on the use of nondestructive field methods for quality control/quality assurance may be necessary.

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Development of a Capacitor Probe to Detect Subsurface Deterioration in Concrete

MRS Proceedings ◽

10.1557/proc-503-231 ◽

1997 ◽

Vol 503 ◽

Cited By ~ 2

Author(s):

B. K. Diefenderfer ◽

I. L. Al-Qadi ◽

J. J. Yoho ◽

S. M. Riad ◽

A. Loulizi

Keyword(s):

Dielectric Constant ◽

Portland Cement ◽

Electromagnetic Waves ◽

Low Cost ◽

Complex Dielectric Constant ◽

Life Cycle Costs ◽

Parallel Plates ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Set Up

ABSTRACTPortland cement concrete (PCC) structures deteriorate with age and need to be maintained or replaced. Early detection of deterioration in PCC (e.g., alkali-silica reaction, freeze/thaw damage, or chloride presence) can lead to significant reductions in maintenance costs. However, it is often too late to perform low-cost preventative maintenance by the time deterioration becomes evident. By developing techniques that would enable civil engineers to evaluate PCC structures and detect deterioration at early stages (without causing further damage), optimization of life-cycle costs of the constructed facility and minimization of disturbance to the facility users can be achieved.Nondestructive evaluation (NDE) methods are potentially one of the most useful techniques ever developed for assessing constructed facilities. They are noninvasive and can be performed rapidly. Portland cement concrete can be nondestructively evaluated by electrically characterizing its complex dielectric constant. The real part of the dielectric constant depicts the velocity of electromagnetic waves in PCC. The imaginary part, termed the “loss factor,” describes the conductivity of PCC and the attenuation of electromagnetic waves.Dielectric properties of PCC have been investigated in a laboratory setting using a parallel plate capacitor operating in the frequency range of 0.1 to 40.1MIHz. This capacitor set-up consists of two horizontal-parallel plates with an adjustable separation for insertion of a dielectric specimen (PCC). While useful in research, this approach is not practical for field implementation. A new capacitor probe has been developed which consists of two plates, located within the same horizontal plane, for placement upon the specimen to be tested. Preliminary results show that this technique is feasible and results are promising; further testing and evaluation is currently underway.

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