Seawater Corrosion Resistance of Low Heat Portland Cement Concrete

2015 ◽  
Vol 814 ◽  
pp. 207-213
Author(s):  
Ning Wang ◽  
Xiao Wei Cheng ◽  
Yun Xia Yang
Keyword(s):  
Corrosion Resistance ◽  
Portland Cement ◽  
Test Specimen ◽  
Sem Analysis ◽  
Corrosion Mechanism ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Quality Change ◽  
Seawater Corrosion ◽  
Drying Test

With the analysis of the seawater corrosion effect on low-heat Portland cement concrete under wetting-drying test, the compressive strength and quality change of concrete test specimen were investigated for different test periods. According to the evaluation of seawater corrosion resistance, the low-heat Portland cement showed better corrosion resistance than that of ordinary Portland cement and moderate-heat Portland cement. Moreover, the corrosion mechanism was expounded through XRD and SEM analysis. It was found that lots of C2S in the low-heat Portland cement play an important role in corrosion resistance of cement concrete.

scholarly journals Sulfuric acid corrosion of geopolymer concrete with mineral additives from wastes

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Nadezhda Eroshkina ◽  
Mikhail Chamurliev ◽  
Mark Korovkin
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Portland Cement ◽  
Geopolymer Concrete ◽  
Acid Solutions ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Demolition Waste ◽  
Sulfuric Acid Solutions ◽  
Mineral Additives

The effect of mineral additives such as crushed ash and individual building demolition waste on the corrosion resistance of geopolymer concrete based on screening the crushed granite and blast furnace slag in an environment of sulfuric acid solutions was studied. The corrosion resistance of concrete was evaluated by the kinetics of reducing the mass and strength of samples in sulfuric acid solutions with a concentration of 2,5 and 5 % for 10 days. It was shown that replacing 50 % of granite powder with ground crushed bricks or ash significantly increases the corrosion resistance of geopolymer materials. It was established that due to the formation of poorly soluble products of the interaction of sulfuric acid and concrete in the pores of a geopolymer stone, an interface is formed between the undestructed material and the zone subjected to destructive processes, which impedes the penetration of the corrosive medium into the material. The study also conducted comparative studies of the corrosion resistance of Portland cement concrete with various water-cement ratios. The research results showed that under the influence of sulfuric acid in Portland cement concrete this border does not form and a rapid loss of mass and strength occurs in the samples. The established feature of the process of destruction of geopolymer concrete in a solution of sulfuric acid is the reason for its higher resistance in comparison with cement concrete.

Influence of Rubber Crumb Addition to Portland Cement Concrete

2011 ◽  
Vol 391-392 ◽  
pp. 600-605
Author(s):  
Hai Bo Zhang
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Coupling Agent ◽  
Sem Analysis ◽  
Cement Matrix ◽  
Rubber Crumb ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Polar Function ◽  
Rubber Concrete

In this paper, two kinds of rubber surface modifying methods were studied. One was bis[3-(triethoxysilyl) propyl] tetrasulfide (Si-69) silicon alkane coupling agent and the other was crylic acid coupling agent. The mechanical properties of cement concrete with modified rubber crumb and with non-modified rubber crumb were tested respectively. The results show that as the rubber crumb addition rises, the toughness of concrete with non-modified rubber crumb increases while the compressive strength decreases, and both thoughness and compressive strength of cement concrete with modified rubber crumb increase. The chloride impermeability of the rubber concrete are much better than that of the Portland cement concrete. After surface modification the chloride impermeability can be improved more. The thermoanalysis proves that the surface of modified rubber crumb is grafted by polar function groups, so the surface changes from hydrophobic to hydrophilic. The scanning electron microscopy (SEM) analysis confirms that the interface between rubber crumb and cement matrix is improved.

Development of a Capacitor Probe to Detect Subsurface Deterioration in Concrete

1997 ◽  
Vol 503 ◽  
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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