Use of ammonium nitrate solution to simulate and accelerate the leaching of cement pastes due to deionized water

1997 ◽  
Vol 49 (181) ◽  
pp. 295-301 ◽  
Author(s):  
C. Carde ◽  
G. Escadeillas ◽  
A. H. François
Keyword(s):  
Ammonium Nitrate ◽  
Nitrate Solution ◽  
Deionized Water ◽  
Cement Pastes ◽  
Ammonium Nitrate Solution

Degradation of Materials Based on Alkali-Activated Blast-Furnace Slag after Exposure to Aggressive Environments

2021 ◽  
Vol 325 ◽  
pp. 131-136
Author(s):  
Iveta Plšková ◽  
Petr Hrubý ◽  
Libor Topolář ◽  
Michal Matysík
Keyword(s):  
Blast Furnace ◽  
Ammonium Nitrate ◽  
Sodium Sulfate ◽  
Blast Furnace Slag ◽  
Nitrate Solution ◽  
Ammonium Nitrate Solution ◽  
Degradation Of Materials ◽  
Non Destructive ◽  
Furnace Slag ◽  
Alkali Activated

The paper summarizes partial results of a study of degradation of materials based on alkali-activated blast-furnace slag (AAS) and comparative on cement CEM III/A 32.5 R after exposure to aggressive environments. It further specifies the possibilities for utilising destructive and non-destructive techniques to determine the progress of degradation and characterizes the degree of their correlation. After 28 days of ageing in a water environment, the produced test specimens (40×40×160 mm beams) were placed in aggressive media (ammonium nitrate solutions; sodium sulfate, rotating water) and after subsequent 28, 56 and 84 days of degradation were subjected to testing. Testing comprised both a destructive form (determination of compressive strength and flexural strength) and a selected non-destructive technique (Impact-echo method). The partial outputs were supplemented by the results acquired from monitoring weight changes. In addition, the development of Ultrasonic Pulse Velocity in relation to the progress of the degradation processes was also monitored. While the exposure of both test specimens to water and sodium sulfate did not result in any significant changes, the exposure to the ammonium nitrate solution exhibited rapid signs of degradation associated with a significant reduction in functional characteristics.

Microstructural and permeability changes due to accelerated Ca leaching in ammonium nitrate solution

2014 ◽  
pp. 431-438 ◽  
Author(s):  
Quoc Phung ◽  
Norbert Maes ◽  
Diederik Jacques ◽  
Geert De Schutter ◽  
Guang Ye
Keyword(s):  
Ammonium Nitrate ◽  
Nitrate Solution ◽  
Permeability Changes ◽  
Ammonium Nitrate Solution

Electrical conductivity, speeds of sound, and viscosity of aqueous ammonium nitrate solutions

2001 ◽  
Vol 79 (8) ◽  
pp. 1207-1212 ◽  
Author(s):  
Abdul Wahab ◽  
Sekh Mahiuddin
Keyword(s):  
Electrical Conductivity ◽  
Ammonium Nitrate ◽  
Structural Information ◽  
Ion Pairs ◽  
Nitrate Solution ◽  
Hydration Number ◽  
Isentropic Compressibility ◽  
Speeds Of Sound ◽  
Ammonium Nitrate Solution ◽  
Nitrate Solutions

Density, electrical conductivity, speeds of sound, and viscosity of aqueous ammonium nitrate solutions were measured as functions of concentration (m, mol kg–1) (0.1599 [Formula: see text] m [Formula: see text] 20.42) and temperature (T, K) (273.15 [Formula: see text] T [Formula: see text] 323.15). Experimental values are consistent with the reported data. Variation of isotherms of electrical conductivity, isentropic compressibility, and structural relaxation time with concentration evoke structural information on the ion solvation in aqueous ammonium nitrate solution at different concentration regions. The primary hydration numbers of ammonium nitrate were estimated at a particular concentration at which the isentropic compressibility isotherms converge. The existence of free hydrated ions, resulting from strong ion solvent interactions in dilute to 9.1 mol kg–1, the solvent-separated ion-pairs resulting from the relative competition between the ion–solvent and the ion–ion interactions in 9.1 to 12.0 mol kg–1, and the solvent-shared ion-pairs beyond 12.0 mol kg–1 resulting from a decrease in the number of solvent molecules, govern the transport process.Key words: electrical conductivity, speeds of sound, viscosity, ammonium nitrate, hydration number.

Mössbauer studies of the corrosion products of iron formed in aqueous ammonium nitrate solution

1983 ◽  
Vol 23 (7) ◽  
pp. 733-752 ◽  
Author(s):  
Pushpalatha C. Bhat ◽  
M.P. Sathyavathiamma ◽  
N.G. Puttaswamy ◽  
R.M. Mallya
Keyword(s):  
Ammonium Nitrate ◽  
Nitrate Solution ◽  
Corrosion Products ◽  
Mössbauer Studies ◽  
Ammonium Nitrate Solution

Effect of Limestone Fillers on Ca-Leaching and Carbonation of Cement Pastes

2016 ◽  
Vol 711 ◽  
pp. 269-276 ◽  
Author(s):  
Quoc Tri Phung ◽  
Norbert Maes ◽  
Diederik Jacques ◽  
Geert de Schutter ◽  
Guang Ye
Keyword(s):  
Nitrate Solution ◽  
Elevated Pressure ◽  
Economic Benefits ◽  
Chemical Degradation ◽  
Leaching Rate ◽  
Carbonation Depth ◽  
Cement Pastes ◽  
Microstructural Alterations ◽  
Ammonium Nitrate Solution ◽  
Degradation Rates

Because of its environmental and economic benefits, part of cement is replaced by limestone fillers (LS). However, the effect of LS on the chemical degradation of cement-based materials is still unclear. In this study, accelerated leaching and carbonation were applied on cement pastes to study the effects of LS replacement on the degradation rates and microstructural alterations of degraded materials. Ammonium nitrate solution was used to accelerate the leaching process, while carbonation was speeded up by applying an elevated pressure gradient of pure CO2 on samples with 65% relative humidity. The carbonation rate was characterized by phenolphthalein carbonation depth and CO2 uptake, while leaching rate was quantified by phenolphthalein leaching depth and Ca-leached amount. Leached/carbonated samples were analyzed by a series of post-analysis techniques to characterize the microstructural and mineralogical changes. Results showed that, for a similar w/c ratio, a higher LS replacement resulted in lower leaching rate. For carbonation, LS replacement promoted the CO2 uptake despite similar carbonation depth. Furthermore, LS replacement led to less C-S-H carbonation compared to samples without LS.

scholarly journals Comparison of McMaster and Mini-FLOTAC effi ciency methods in diagnostics of Ascaris suum infection in young pigs

2020 ◽  
pp. 85-91
Author(s):  
O. Kruchynenko ◽  
A. Antipov
Keyword(s):  
Specific Gravity ◽  
Ammonium Nitrate ◽  
Nitrate Solution ◽  
Diagnostic Efficiency ◽  
Young Pigs ◽  
Ammonium Nitrate Solution ◽  
Effi Ciency ◽  
Scientific Laboratory ◽  
Flotac Technique ◽  
Efficiency Comparison

The coproovoscopic methods involving count chambers are widely used in the veterinary practice for diagnostics. These methods are important in assessments of the prevalence rates of nematode infections in pigs and for FECR tests. However, more basic data is needed on the efficiency of the commercial methods of diagnostics, tested at the different specific gravity of the flotation solutions. In a thorough analysis of publications of Ukrainian scientists, we have found that the data is sparse on the efficiency comparison of the modified McMaster’s and MiniFLOTAC methods. The aim of our study was to compare the efficiency of the commercial coproovoscopic techniques: the modified McMaster’s method (with sensitivity of 25 EPG), and MiniFLOTAC combined with Fill-FLOTAC (with sensitivity of 5 EPG) in testing for A. suum infection in piglets. Results of approbation of the mentioned methods are presented for the following saturated solutions: NaCl (SG=1.2), MgCl2 •6H2 O (SG =1.27) and NH4 NO3 (SG=1.28). Fecal samples were taken at own private farm, in Mlynok village of Onufriivka district, Kirovohrad region from 20 4 month old pigs with spontaneous A. suum infection. The laboratory assessments were performed in the Scientific Laboratory of Parasitology and Veterinary and Sanitary Expertise of the Poltava State Agrarian Academy. It is established that at high rates of A. suum infection in young pigs, McMaster’s method with the ammonium nitrate solution is more efficient compared to the Mini-FLOTAC method. In average, 5331.2 eggs of A. suum were determined per 1 g of feces using the former method, compared to 4567.5 EGP according to the Mini-FLOTAC technique (P < 0.001). The highest diagnostic efficiency of the modified McMasters method and the combination of Mini-FLOTAC and Fill-FLOTAC is seen when ammonium nitrate (NH4 NO3 ) solution of 1.28 SG is used (P < 0.001). Our results add new data on the efficiency of the commercial methods of diagnostics with varying specific gravity of the flotation solutions, for pigs infected with nematodes. Key words: EPG, pigs, nematode, ascariasis, diagnostics, efficiency.

scholarly journals ANALYSIS OF KINETIC CHARACTERISTICS OF BAROMEMBRANE AND ELECTROBARMEMBRANE SEPARATION OF AMMONIUM NITRATE SOLUTION

2020 ◽  
Vol 63 (9) ◽  
pp. 28-36
Author(s):  
Sergey I. Lazarev ◽  
Sergey V. Kovalev ◽  
Dmitry N. Konovalov ◽  
Olga A. Kovaleva
Keyword(s):  
Electrical Conductivity ◽  
Ammonium Nitrate ◽  
Nitrate Solution ◽  
Membrane System ◽  
Transmembrane Pressure ◽  
Membrane Systems ◽  
Specific Output ◽  
Output Stream ◽  
Ammonium Nitrate Solution ◽  
Current Voltage

The paper presents a generalized analysis of literature data on the current-voltage, omics characteristics and electrical conductivity of membrane systems. Based on an analysis of the literature, it is noted that electrodialysis is a promising method for the separation of solutions for the production of ammonium nitrate. An analysis of literature revealed that the application of an external constant electric field to the membrane separation of solutions containing charge-transporting components (nitrate ions and ammonium ions) causes the directed transfer of cations and anions through the membranes. The studies revealed that with the baromembrane separation of the studied solutions with increasing transmembrane pressure, the specific output stream increases. This is due to an increase in the driving force of the process. For the OFAM-K anode membrane, with an increase in the current density, with the electrobaromembrane separation of the ammonium nitrate solution, the specific output stream decreases, which is associated with a change in the pH value of the acidified anode permeate. nd for the OPMN-P cathode membrane, the specific output stream increases with a change in the pH of the alkalized cathode permeate. A modified mathematical equation is proposed for theoretical calculation of the specific output stream and the retention coefficient of the OFAM-K and OPMN-P nanofiltration membranes. Experimental studies of membrane systems equipped with the anode OFAM-K and the near-cathode OPMN-P membranes from voltage and transmembrane pressure revealed that for the aqueous solution of ammonium nitrate there are two characteristic periods on the current-voltage, omics characteristics and electrical conductivity of the membrane system (the first period is beyond regime, dissociation of water (H+ and OH-) at the phase boundary with the advent of additional electric current carriers, the second is the degradation of the active layer of a semipermeable membrane). When studying the current-voltage characteristics of a membrane system equipped with an anode OFAM-K and a near-cathode OPMN-P membranes, when separating model and technological solutions, a decrease in the total omics resistance of the system is observed, which is associated with the solution throttling process.

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