scholarly journals Strength and Solidification Mechanism of Silt Solidified by Polyurethane

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Fengyuan Li ◽  
Chaojie Wang ◽  
Yangyang Xia ◽  
Yanjie Hao ◽  
Peng Zhao ◽  
...  
Keyword(s):  
Unconfined Compressive Strength ◽  
Immersion Time ◽  
Mercury Intrusion Porosimetry ◽  
Polymer Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Grouting Material ◽  
Permeable Polymer ◽  
Solidification Mechanism

To determine the mechanism and strength characteristics of solidification of silt by a permeable polyurethane grouting material, the effects of polymer content, soil moisture, and immersion time on the unconfined compressive strength (UCS) of the silt have been studied. The results showed that the permeable polymer grouting material can significantly improve the performance of silt: (1) A higher amount of polymer produced a greater strength in the solidified soil. (2) The strength of the solidified soil increased as the immersion time was increased. (3) Moisture in the soil was not conducive to improving the strength of the solidified soil. The X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) have proven that polyurethane does not react with the silt, but they could improve the strength of the silt through physical action. Mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) were performed to find that polymers can reduce soil porosity, and the addition of polyurethane improved the strength of the silt mainly through adhesion, wrapping, filling, and bridging.

Carbide slag–activated ground granulated blastfurnace slag for soft clay stabilization

2015 ◽  
Vol 52 (5) ◽  
pp. 656-663 ◽  
Author(s):  
Yaolin Yi ◽  
Liyang Gu ◽  
Songyu Liu ◽  
Anand J. Puppala
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Soft Clay ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Carbide Slag ◽  
Calcium Silicate Hydrates ◽  
Blastfurnace Slag ◽  
Ucs Test ◽  
Curing Age

This study addresses the use of an industry by-product, carbide slag (CS), to activate another industry by-product, ground granulated blastfurnace slag (GGBS), for soft clay stabilization in comparison to Portland cement (PC). The properties of CS–GGBS stabilized clays were investigated through unconfined compressive strength (UCS) test, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicated that the optimum CS content for the CS–GGBS stabilized clay to yield the highest UCS was 4%–6%, varying slightly with curing age and GGBS content. The UCS of the optimum CS-GGBS stabilized clays was more than twice that of the corresponding PC stabilized clays. The main hydration products detected for the CS–GGBS stabilized clays included calcium silicate hydrates (CSH), calcium aluminate hydrates (CAH), and alumino-ferrite monosulfate (AFm).

Effect of Metakaolin Sand on Properties of Cement Composites

2014 ◽  
Vol 897 ◽  
pp. 176-179
Author(s):  
Ľudovít Krajči ◽  
Ivan Janotka ◽  
Marta Kuliffayova ◽  
Peter Uhlik
Keyword(s):  
Portland Cement ◽  
Mercury Intrusion Porosimetry ◽  
Structure Refinement ◽  
Hydrate Formation ◽  
Raw Material ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Positive Effect

The Slovak natural raw material kaolin sand containing 36 wt.% of kaolinite from Vyšný Petrovec deposit was thermally transformed at 650 °C for 1 hour to the metakaolin sand with relevant content of metakaolinite. Behaviour of cement composites having replacement of Portland cement with metakaolin sand including 0; 5; 10 and 15 wt.% of metakaolinite and water to solids ratio of 0.5 cured in water for 28 days and 90 days was studied by thermal analysis, X-ray diffraction analysis and mercury intrusion porosimetry analysis. The study concerned calciumsilica hydrate and calcium aluminate hydrate formation, portlandite dehydroxylation and calcite decarbonation. The influence of curing time and metakaolinite content were estimated. The replacement of Portland cement by metakaolin sand led to positive effect on relevant compressive strengths. The changes in microstructure involved especially reduction in portlandite content and pore structure refinement.

Microstructural and Microanalytical Study on Cementitious Materials Subjected to the Cyclic Sulfate Environment

2014 ◽  
Vol 898 ◽  
pp. 371-374
Author(s):  
Xiao Lu Yuan
Keyword(s):  
Electron Microscope ◽  
Mercury Intrusion Porosimetry ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Lower Porosity ◽  
Scanning Electron

Microstructural properties have been studied in cementitious materials, which were subjected to cyclic sulfate exposure, through x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum. Portlandite in OPC-GBFS concrete is mainly converted to gypsum and ettringite. Concrete subjected to the cyclic sulfate attack has a lower porosity and the higher amount of macro-pores than that before exposure. Concretes incorporating FA or GBFS had lower porosity and higher amount of micro-pores than OPC concrete.

scholarly journals Utilization of Municipal Solid Waste Incineration Bottom Ash as Fine Aggregate of Cement Mortars

2021 ◽  
Vol 13 (16) ◽  
pp. 8832
Author(s):  
Byeong-Hun Woo ◽  
In-Kyu Jeon ◽  
Dong-Ho Yoo ◽  
Seong-Soo Kim ◽  
Jeong-Bae Lee ◽  
...  
Keyword(s):  
Solid Waste ◽  
Mercury Intrusion Porosimetry ◽  
Bottom Ash ◽  
Fine Aggregate ◽  
Cement Composites ◽  
Backscatter Electron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Scanning Electron

Incineration bottom ash is generated by the incineration of solid waste. Household solid waste is increasing every year and so is incineration bottom ash. This is a problem to treat the incineration bottom ash because the ash has many toxic components. Cement composites can solve this problem and there are many studies for using the bottom ash as fine aggregate. To evaluate the usage of incineration bottom ash, compressive strength, mercury intrusion porosimetry, scanning electron microscopy-backscatter electron, X-ray diffraction, and toxicity characteristic leaching processes were performed. When using incineration bottom ash up to 20% of substitution, the compressive strength in all cases was increased. This study showed how the filler effect appeared well in the cement composites through the scanning electron microscopy-backscatter electron, and mercury intrusion porosimetry. X-ray diffraction indicated the possibility of an alkali-silica reaction of the aggregate with the components of incineration bottom ash. This problem is an obstacle to applying the incineration bottom ash as a fine aggregate. In addition, the toxicity characteristic leaching process was shown to be under the threshold of the Korean standard, however, this should nuanced by the consideration of amorphity. Comprehensively, incineration bottom ash could be used as a fine aggregate of up to 20% of substitution. However, the pre-treatment would need to eliminate or reduce alkali reactive components and heavy metals.

Physical and Chemical State of the Concrete Piers of the Former Franz Joseph Bridge Built in 1891

2016 ◽  
Vol 691 ◽  
pp. 297-308
Author(s):  
Ivan Janotka ◽  
Peter Paulík ◽  
Patrik Ševčík ◽  
Michal Bačuvčík
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Elasticity Module ◽  
European Standards ◽  
Physical And Chemical ◽  
And Chemical Properties

This article discusses the properties of concrete within the piers of the Old Bridge in Bratislava (former Franz Joseph Bridge). It was the first permanent bridge across the river Danube in Bratislava as well as within the present territory of Slovakia. Mechanical, physical and chemical properties were verified on core drills, some of them being almost 23 m long. The concretes were tested for dynamic and Young’s elasticity module and compressive strengths. Subsequently the fines of concrete specimens were studied by the X-ray diffraction, TG-DTA and mercury intrusion porosimetry techniques and also by chemical analyses and SEM observations. The piers were made from 5 different concrete kinds. The concrete in the caissons and in the piers does not fulfil the criteria for structural concrete defined in the present European standards. This finding seriously suggests that carrying capacity of the piers after the reconstruction of the bridge, without any strengthening would become questionable.

scholarly journals Influences of Ultrafine Slag Slurry Prepared by Wet Ball Milling on the Properties of Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Yubo Li ◽  
Shaobin Dai ◽  
Xingyang He ◽  
Ying Su
Keyword(s):  
Environmental Sustainability ◽  
Blast Furnace Slag ◽  
Ball Mill ◽  
High Performance ◽  
Mercury Intrusion Porosimetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

The application of ultrafine ground-granulated blast-furnace slag (GGBFS) in concrete becomes widely used for high performance and environmental sustainability. The form of ultrafine slag (UFS) used in concrete is powder for convenience of transport and store. Drying-grinding-drying processes are needed before the application for wet emission. This paper aims at exploring the performances of concrete blended with GGBFS in form of slurry. The ultrafine slag slurry (UFSS) was obtained by the process of grinding the original slag in a wet ball mill, which was mixed in concrete directly. The durations of grinding were 20 min, 40 min, and 60 min which were used to replace Portland cement with different percentages, namely, 20, 35, and 50, and were designed to compare cement with original slag concrete. The workability was investigated in terms of fluidity. Microstructure and pore structure were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). The fluidity of concrete mixed with UFSS is deteriorated slightly. The microstructure and early strength were obviously improved with the grind duration extended.

scholarly journals Effects of Gamma-Ray Irradiation on Hardened Cement Mortar

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Yuliia Khmurovska ◽  
Petr Štemberk ◽  
Svyatoslav Sikorin ◽  
Jiří Němeček ◽  
Daria Jóźwiak-Niedźwiedzka ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Gamma Ray ◽  
Mercury Intrusion Porosimetry ◽  
Cement Mortar ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Significant Difference ◽  
Gamma Ray Irradiation ◽  
Control Samples

AbstractThe effect of gamma-ray irradiation on cement mortar properties is investigated in this study in order to understand the mechanism behind the strength and stiffness reduction, which may be significant according to the available researches. 60Co irradiation facility with the generating dose rate of 0.1–10 Gy/s and the total activity of 4.4·1015 Bq (120 kCi) was used to perform the irradiation, so that the total observed dose of the irradiated samples reached the values ranging from 12.0 to 15.0 MGy. An identical set of control samples was placed in the same laboratory conditions away from gamma radiation. The results of nanoindentation, X-ray diffraction analysis and mercury intrusion porosimetry of the irradiated and the control samples are shown and explained in detail in this study. The nanoindentation creep compliance and the nanoindentation elastic modulus of the irradiated and the control samples do not show any significant difference. The mineral composition obtained using the X-ray diffraction analysis of the irradiated and the control samples is also similar. The pore structure rearrangement and microcrack occurrence, which were evidenced by the mercury intrusion porosimetry and scanning electron microscopy, led to the porosity increase and may be attributed to the significant decrease of compressive strength.

scholarly journals From Nanostructural Characterization of Nanoparticles to Performance Assessment of Low Clinker Fiber–Cement Nanohybrids

2019 ◽  
Vol 9 (9) ◽  
pp. 1938 ◽  
Author(s):  
Styliani Papatzani ◽  
Kevin Paine
Keyword(s):  
Flexural Strength ◽  
Mercury Intrusion Porosimetry ◽  
Manufacturing Processes ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Differential Thermogravimetry

With the current paper three nano-Montmorillonites (nMt) are applied in cement nanohybrids: an organomodified nMt dispersion, nC2; an inorganic nMt dispersion, nC3; and an organomodified powder, nC4. nC4 is fully characterized in this paper (X-ray diffraction, scanning electron microscopy/X-ray energy dispersive spectroscopy and thermal gravimetric analysis/differential thermogravimetry. Consecutively a ternary non pozzolanic combination of fiber–cement nanohybrids (60% Portland cement (PC) and 40% limestone (LS)) was investigated in terms of flexural strength, thermal properties, density, porosity, and water impermeability. Flexural strength was improved after day 28, particularly with the addition of the inorganic nMt dispersion. There was no change in density or enhancement in pozzolanic reactions for the powder nMt. Mercury intrusion porosimetry showed that the pore related parameters were increased. This can be attributed to mixing effects and the presence of fibers. Water impermeability tests yielded ambiguous results. Clearly, novel manufacturing processes of cement nanohybrids must be developed to eliminate mixing issues recorded in this research.

scholarly journals Structural changes in phenol-intercalulated hydrotalcite caused by heating

Clay Minerals ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 771-779 ◽  
Author(s):  
J. Cornejo ◽  
R. Celis ◽  
I. Pavlovic ◽  
M. A. Ulibarri ◽  
M. C. Hermosín
Keyword(s):  
Ftir Spectroscopy ◽  
Thermal Effects ◽  
Structural Changes ◽  
Mercury Intrusion Porosimetry ◽  
Nitrogen Adsorption ◽  
Total Weight Loss ◽  
X Ray Diffraction ◽  
Phenol Adsorption ◽  
X Ray ◽  
Mercury Intrusion

AbstractThermal analysis (DTA-TG-DTG), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nitrogen adsorption and mercury intrusion porosimetry techniques were used to assess the structural changes induced upon heating of two hydrotalcite-phenol (trichloro- and trinitrophenol, HT-TCP and HT-TNP) complexes, and the results were compared with those obtained for the original hydrotalcite (HT) sample. The DTA revealed thermal effects that depended on the nature of the interlayer ion in the complexes. The total weight loss (TG-DTA) increased from 37% for the original HT to 40% for HT-TCP and 77% HT-TNP, as the amount of phenol increased. The XRD and FTIR spectroscopy showed that the calcination product (550°C) of the HT-phenol complexes was indistinguishable from that formed from the original HT. Since HT-phenol complexes were prepared by phenol adsorption on calcined HT, our results confirm the recyclability of HT-like compounds as sorbents for phenols.

scholarly journals Changes in mineralogy and microstructure of a lime-treated silty soil during curing time

2020 ◽  
Vol 195 ◽  
pp. 03044
Author(s):  
Zi YING ◽  
Yu-jun Cui ◽  
Nadia Benahmed ◽  
Myriam Duc
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Soil Samples ◽  
Time Effect ◽  
Curing Time ◽  
X Ray Diffraction ◽  
Lime Treatment ◽  
Treated Soil ◽  
X Ray ◽  
Mercury Intrusion

Lime treatment is widely applied to improve the workability and long-term durability of soils. In this study, the curing time effect on the mineralogy and microstructure of lime-treated soil was investigated. The soil samples were prepared with 2 % lime and statically compacted at dry (w = 17 %) and wet (w = 20%) sides of optimum. X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP) were performed on lime-treated soil at various curing times. The presence of XRD peaks attributed to portlandite even after 150 days curing time indicated that it was not totally converted in cementitious compounds after reaction with silica and alumina from clay minerals. By contrast, no obvious XRD reflections of well-crystallized cementitious compounds were identified. Furthermore, all samples compacted at dry and wet side of optimum exhibited bi-modal pore size distribution, with a decrease of macro-pore frequency with increasing water content. The microstructure changes with increasing curing time did not follow monotonic tendency. On the whole, the quantities of pores less than 0.006 μm and micro-pores increased and the quantity of macro-pores decreased with increasing curing time due to the possible creation of poorly crystallized or amorphous cementitious compounds.

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