Logarithmic Decrement and Dynamic Modulus of Coated Cement Concrete

Author(s):  
Masakazu Mayama ◽  
Masatoshi Harada
2006 ◽  
Vol 302-303 ◽  
pp. 493-499
Author(s):  
Masakazu Mayama ◽  
Masatoshi Harada

This report presents a research on vibration absorption properties of coated cement concrete, by discussing the logarithmic decrement and dynamic modulus obtained from bending vibration test at various temperatures. The effect of temperature and bitumen content on the vibration properties of materials was evaluated. As temperature and/or coating asphalt content increased, coated cement concrete increased logarithmic decrement and resulted in increasing vibration absorption than the conventional cement concrete. The vibration properties of coated cement concrete were similar to those of conventional cement concrete in the low temperature range. The dynamic modulus of coated cement concrete decreased at higher temperatures. The rate of decrease of dynamic modulus at higher temperatures was comparatively small in comparison with the rate of increase of logarithmic decrement.


2014 ◽  
Vol 578-579 ◽  
pp. 1498-1503
Author(s):  
Chen Fei Wang ◽  
Jing Liu

Different from ordinary Portland cement concrete, the Polypropylene Fiber (PPF) concrete is a new type of concrete and is made through mixing PPF into common concrete. To popularize and apply PPF concrete, this paper carried out a series of experimental study on the durability of PPF concrete under chloride environments. In the present study, three chloride environment tests were conducted on PPF concrete with various volume fraction of PPF (0,0.1%,0.3%,0.5%). The scaling of concrete, the chloride penetration in concrete and the microstructure in concrete were determined. The results indicated that the scaled mass and relative dynamic modulus of elasticity loss decrease with the volume of fiber increasing, Cl-concentration has a much higher content near the sample surface, adding 0.1% PPF into concrete has the perfect resistance of Cl-penetration. More fibers can delay the development of cracks, but that will reduce the inner density of concrete.


Author(s):  
S. Nazarian ◽  
D. Yuan ◽  
A. Medichetti

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.


2011 ◽  
Vol 250-253 ◽  
pp. 673-677
Author(s):  
Zhen Wu Shi ◽  
Shuang Liu ◽  
Rui Rui Zhang

Based on the evaluation of fibrous concrete materials and the experiments of freezing-thawing resistance home and abroad, the present experiment takes relative dynamic modulus of elasticity and rate of mass reduction as an analytical index to conduct a comparative study on the effects of the mixing of four kinds of polypropylene fiber on the cement concrete freezing resistance. The results show that different kinds of polypropylene fiber have different influences on cement concrete freezing resistance. And some polypropylene can improve it while others may make it decreased.


2012 ◽  
Vol 2 (11) ◽  
pp. 189-191 ◽  
Author(s):  
Yogendra O Patil ◽  
◽  
P.N.Patil P.N.Patil ◽  
Dr. Arun Kumar Dwivedi

PCI Journal ◽  
2015 ◽  
Vol 60 (6) ◽  
pp. 39-50 ◽  
Author(s):  
Brett Tempest ◽  
Clarke Snell ◽  
Thomas Gentry ◽  
Maria Trejo ◽  
Keith Isherwood

1997 ◽  
Vol 503 ◽  
Author(s):  
B. K. Diefenderfer ◽  
I. L. Al-Qadi ◽  
J. J. Yoho ◽  
S. M. Riad ◽  
A. Loulizi

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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