In this paper, uniaxial compression tests, multistage loading tests, and electrochemical tests were adopted to investigate the strain characteristics, failure characteristics, and electrochemical impedance of anchor bolts in a cement-gypsum composite. The uniaxial compression test results showed that the uniaxial compressive strength 
 
 
 
 σ
 
 
 c
 
 
 
 of the three specimens were 4.4 MPa, 4.0 MPa, and 3.1 MPa, respectively, under three different osmotic pressures. The analysis of the multistage loading tests revealed that the directions of most cracks were approximately consistent with the load-bearing direction. Moreover, the existence of osmotic pressure increased the creep deformation capacity of the specimen; the greater the osmotic pressure, the stronger the deformation capacity of the specimen. The curvature relationship of the total strain curve of the three specimens was KS12 > KS22 > KS32, and the total strain curve of S32 was close to a straight line. When comparing the creep strain variation characteristics of the three specimens, it was found that, with the increase of osmotic pressure, the proportion of creep strain within the total strain gradually increased, while the proportion of corresponding elastic strain gradually decreased. Compared with the specimen before failure, the electrochemical test in the failure stage proved the variability of the Bode curves and Nyquist curves. When the osmotic pressure was 0.15 Mpa, the Bode diagram of specimen S32 in the low frequency band showed a large jump, which was stable after entering the high frequency band.

Electrochemical Experiment to Evaluate the Impact of Multistage Load and Osmotic Pressure on Anchor Bolt

The effects of SRB on macrocell corrosion of X70 steel in soils were studied by using polarization curve technique,electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM) and EDXA.It was noted that the SRB obviously affected the macrocell corrosion behavior of X70 steel.When X70 steel formed a macrocell between inoculation SRB or bactericide clay and sand,X70 steel in clay was an anode,while that in sand was a cathode.Along with test going,the corrosion rate of X70 steel,which was buried by natural style,was slow,but the anode of macro cell kept a rapid corrosion rate.The corrosion rate of X70 steel in clay was faster than that in natural condition.Current density and electromotive force of macro cell of X70 steel formed between inoculation SRB clay and sand was much larger than that between bactericide clay and sand.The corrosion rate of anode in inoculation SRB clay was 4.93 times of that in natural condition.The corrosion rate of anode in bactericide clay was 2.45 times of that in natural condition.When the area ratio of cathode to anode being 15∶1,the corrosion ratio of anode in inoculation SRB clay and bactericide clay were respectively 5.01 and 2.33 times respectively of that in condition of the area ratio of cathode to anode being 1∶1.

Effects of srb on macrocell corrosion of x70 steel in soils

The short-term corrosion behavior of X80 pipeline steel was investigated in Huo'erguosi soil with saturated water using electrochemical measurement,scanning electron microscopy(SEM) and energy dispersive spectrum(EDS) analysis.The results showed that the corrosion rate of X80 steel presented the variational trend of rapid increase→sharp decrease→slow increase with the increase of corrosion time,and corrosion tendency increases,this is induced by change of corrosion morphology from uniform corrosion to localized corrosion.The corrosion product is basically iron oxides and iron sulfides.The corrosion resistance and corrosion morphology of X80 steel samples is dependent on the integrality and compactness of corrosion product films.

Study on Short-term Corrosion Behavior of X80 Pipeline Steel in Huo'erguosi Soil with Saturated Water

The influence of components of simulated acid rain(SAR) on corrosion behaviors of 1Cr18Ni9Ti stainless steel in soil was studied by means of polarization curves and electrochemical impedance spectroscopy(EIS).The results indicated that the components of SAR obviously affected the corrosion behaviors of 1Cr18Ni9Ti stainless steel.When the concentration ratio of SO42-to NO3-of SAR decreased,the corrosion rate of the stainless steel would also decrease.EIS of 1Cr18Ni9Ti stainless steel consisted of two capacitive arcs,the corrosion was controlled by oxygen diffusion process.

Influence of Components of Simulated Acid Rain on Corrosion Behaviors of 1Cr18Ni9Ti Stainless Steel in Soil

Study on the Corrosion Behaviors of Zinc in Yellow Soil Leached with Simulated Acid Rain

The EIS behavior, corrosiveness, and seepage structure of sand of varied water content were studied by means of electrochemical impedance spectroscopy under the three-electrode system. The...

Electrochemical impedance spectroscopy of sand of varied particle size and water content using the three-electrode system

The invention relates to the field of building foundation engineering, in particular to a HDPE double-wall corrugated pipe foundation and a construction process thereof. The foundation comprises upper part-removed HDPE double-wall corrugated pipes and prefabricated reinforcement cages; and the prefabricated reinforcement cages are mounted in the HDPE double-wall corrugated pipes at the construction site, and are lifted in an excavated foundation pit by a crane. The segmented manufacturing and the segmented lifting are formed for the HDPE double-wall corrugated pipes and the reinforcement cages; reinforcements are welded in joints; and corrugated pipes are connected by two insertion pipes in butt joint. The corrugated pipes are manually placed; and the HDPE double-wall corrugated pipes are fixed on the foundation by spacing every a certain distance by clamping pieces and anchor ribs. Finally, soil layers are filled to reach the center heights of the pipes; and concrete is cast. The HDPE double-wall corrugated pipe foundation has such advantages as simple structural form, convenience for construction, shortening of the construction period, relatively lower manufacturing cost and excellent bearing capacity.

HDPE double-wall corrugated pipe foundation and construction process thereof

The invention relates to the field of grouting engineering, and more specifically relates to grouting composite slurry used under a dynamic water condition and a preparation method thereof. The grouting composite slurry is prepared from the following components in parts by weight: 100 parts of ordinary Portland cement, 5-10 parts of coal-series metakaolin, 1.0-1.5 parts of a water reducer, 0.05-0.1 part of a defoaming agent, 0.1-0.4 part of polyacrylamide, 0.1-0.3 part of polyvinyl alcohol, 60-120 parts of water and 3-5 parts of a liquid accelerator. The grouting composite slurry used under the dynamic water condition is based on an action mechanism of polymer modification, component screening is carried out, and the composite slurry which is no-toxic and safe, has good product stability,is not easily dissolved into water, and has a high retention rate and good anti-dispersion property under the dynamic water condition is developed. Therefore, the problems that the retention rate of cement slurry is low, the anti-dispersion property is poor, organic slurry is toxic, a product is unstable, and the like are solved.

Composite slurry used under dynamic water condition and preparation method thereof

In this study, the equations for electrochemical impedance characteristics, including Nyquist diagrams and Bode chart, of contaminated soils was obtained by using soil mechanics, chemical, electrochemical and microscopic analysis. The analysis is implemented in light of the relationship between mineral composition, microstructure, macro-performance and electrochemical characteristics of contaminated soil. The parameters for physical, mechanical and electrochemical properties were then obtained based on the EIS characteristic. By theoretical EIS analysis, the relationship between electrochemical properties (electrolyte resistance, charge transfer resistance, electric double layer capacitor and diffusion resistance coefficient) and soil properties (the mineral compositions, moisture, soil microstructure, pore distribution and soil strength) was determined. As a result, the equivalent circuit model and corrosion evaluation system for the contaminated soil were established, which can evaluate the soil contaminations and provide advices on electric double layer, electrode material, solid electrolyte and corrosion protections of metallic materials embedded in the soils. It also provides important engineering data and scientific basis for evaluation of ecological suitability, which has significant economic and social benefits.

Ruizhen Xie

Papers

Electrochemical impedance spectroscopy of sand of varied particle size and water content using the three-electrode system

HDPE double-wall corrugated pipe foundation and construction process thereof

Composite slurry used under dynamic water condition and preparation method thereof

A Method for Evaluating Corrosion of Contaminated Soil—Electrochemical Impedance Spectroscopy (EIS) Method