White Portland Cement Research Articles

Analysis of Cement properties using Hyperspectral Remote Sensing methods

Abstract. Understanding building material properties can play a key role in analyzing the health of structural elements in buildings. However, the field and laboratory tests can be laborious, time-consuming, and cost-intensive. Generally, the standard tests employed for characterizing the material properties are destructive in nature, but in the recent past, non-destructive testing (NDT) has given us the ease of understanding the material properties. Hyperspectral remote sensing technology has been exploited as one of the NDT methods for assessing the properties of building components. This study aims to investigate the quality information about cement using the hyperspectral remote sensing method and correlate it with the results of traditional quality testing methods. The materials used in the experiments included Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC), and White Portland Cement (WPC). The cement samples were studied and experimented with for the identification of their types, and their temporal variability and changes in their spectral properties on which the strength of the samples depended were further checked. The study concluded that for OPC, PPC, and WPC, the absorption range is 1970 nm to 2020 nm, which is mainly due to the presence of different chemical compounds in cement. Also, the spectral reflectance decreases with time, and it can be concluded that in the present work, the strength of cement decreases with the decrease in spectral reflectance. Hence, Cement properties can be found using hyperspectral remote sensing data.

A Study of the Influence of Thermoactivated Natural Zeolite on the Hydration of White Cement Mortars.

One trend in the development of building materials is the partial or complete replacement of traditional materials that have a high carbon footprint with eco-friendly ecological raw materials and ingredients. In the present work, the influence of replacing cement with 10 wt% thermally activated natural zeolite on the structural and physical-mechanical characteristics of cured mortars based on white Portland cement and river sand was investigated. The phase compositions were determined by wavelength dispersive X-ray fluorescence (WD-XRF) analysis, X-ray powder diffraction (PXRD), diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), and scanning electron microscopy (SEM), as well as thermogravimetric analysis simultaneously with differential scanning calorimetry (TG/DTG-DSC). The results show that the incorporation of zeolite increases the amount of pores accessible with mercury intrusion porosimetry by about 40%, but the measured strengths are also higher by over 13%. When these samples were aged in an aqueous environment from day 28 to day 120, the amount of pores decreased by about 10% and the compressive strength increased by nearly 15%, respectively. The microstructural analysis carried out proves that these results are due to hydration with a low content of crystal water and the realization of pozzolanic reactions that last over time. Replacing some of the white cement with thermally activated natural zeolite results in the formation of a greater variety of crystals, including new crystalline CSH and CSAH phases that allow better intergrowth and interlocking. The results of the investigations allow us to present a plausible reaction mechanism of pozzolanic reactions and of the formation of new crystal hydrate phases. This gives grounds to claim that the replacement of part of the cement with zeolite improves the corrosion resistance of the investigated building solutions against aggressive weathering.

ASSESSMENT OF THE INFLUENCE OF INORGANIC PIGMENTS ON THE TECHNOLOGICAL PROPERTIES OF DECORATIVE CEMENTS

The article presents the results of research on the influence of inorganic pigments on the technological properties of decorative cements. It has been established that regardless of the color of the pigment, with an increase in its quantity in the system, we get a more saturated and bright color of cement stone, but at the same time there is a negative effect of pigments and technological and physical and mechanical properties of artificial stone. The research was conducted on cement systems based on white Portland cement without additives and on cement systems based on white Portland cement modified with polycarboxylate superplasticizer. An increase in the amount of pigment, regardless of its color, leads to an increase in the water consumption of the cement system, however, when a superplasticizer is introduced, the effect of the pigment is not so significant. At the same time, the introduction of a superplasticizer reduces the water consumption of white cement without the introduction of pigments by an average of 37-40%. In addition, it was established that the introduction of pigments affects the hardening time of cement systems. At the same time, pigments, depending on their color and dosage, have different effects on both the start and end of aging. With an increase in the pigment content in a cement system without a plasticizer, the time of the onset of hardening increases, and the introduction of a permanent pigment has the greatest effect on the end of hardening of such a system. The introduction of pigments into plasticized cement systems increases both the start and end time of hardening. As the number of pigments of all colors increases, the strength of the samples decreases. At the same time, the red pigment leads to the greatest decline in strength at all stages of hardening. The decrease in strength can be explained by the increased water consumption, and, as a result, the increased porosity of pigmented samples compared to samples without the introduction of pigments. Further research aimed at finding additives that will reduce the negative impact of inorganic pigments on the processes of hydration and hardening of the cement system, and therefore on the durability of the obtained artificial stone, will be relevant. At the same time, it is important to preserve the intensity of the color and the absence of sediment formation.

Comparison of Surface Microhardness of Portland Cement Associated with Niobium Oxide and Zirconium Nanoparticles with the Mineral Aggregate Trioxide

To determine the surface microhardness of white portland cement associated with niobium nanoparticles, white portland cement associated with zirconium nanoparticles, and mineral trioxide aggregate. The present study is an experimental in-vitro study. The sample consisted of 03 study groups. These were divided into 09 subgroups of 04 hours, 14 days and 28 days. The instrument used to record the surface mechanical microhardness was the Vickers microdurometer. The Shapiro-Wilk statistical analysis was then performed to identify the normality of the data. The Anova test was applied to compare between the three groups and then the Tukey test for multiple comparisons with a 95% confidence level. White Portland cement associated with zirconium nanoparticles had the highest hardness value (p<0.05), followed by white Portland cement associated with niobium nanoparticles and aggregate control cement of mineral trioxide. The lowest value of surface microhardness was obtained by the addition of mineral trioxide (p<0.05). Surface microhardness values were significantly higher at 28 days than at 04 hours for all groups evaluated. White Portland cement with/without nanoparticulate additives generated higher surface microhardness than the control group added mineral trioxide in the evaluation periods.

Monitoring chemical reactions following the addition of TiO2 nanoparticles in white Portland cement pastes

Monitoring chemical reactions following the addition of TiO2 nanoparticles in white Portland cement pastes

Impact of Increasing Albedo on Choosing the Optimal Tilt Angle to Optimize PV Systems : Case Study

The amount of irradiation energy that is produced by reflecting one's surroundings is measured using albedo. The amount of albedo is affected by factors such as time, position, geometry, and meteorological conditions. The albedo value responds to changes in any of the characteristics described above, even if those changes are just slight. Because of this, modelling albedo can be difficult. This paper applied the optimum tilt angle at 31° with a constant albedo 0.2 for location in Al-Furat Al-Awsat Technical University - at latitude 32°03'30.6" North and longitude 44°24'13.3" East. After treating the surface on which the PV system is installed with white Portland cement, the surface albedo will change to (0.87); the increase in albedo leads to an increase in reflected radiation from the ground on PV panels then increase in the power output, also the results shown to reaching the maximum value of the solar irradiation hitting the PV panels to get maximum value of power output with albedo 0.87 in this location, optimum tilt angle will change to be 42o instated of 31o. This study proved that when the albedo of the surface on which the system is installed changes, so does the optimal tilt angle.

РАСШИРЕНИЕ ФУНКЦИОНАЛЬНЫХ СВОЙСТВ ЦЕМЕНТНО-СИЛИКАТНОЙ КРАСКИ

The paper describes a one-component cement-silicate paint based on white Portland cement and sodium hydrosilicate, which lacks expensive zinc oxide and potassium liquid glass. The paint is supposed to be produced as a dry mixture, which can be applied in the conditions of the construction area using mixers. It is shown that the introduction of chrysotile nano-fibers into the basic composition of the paint allows its use for painting hot surfaces operating at temperatures up to 700 ºC. The use of nanodispersed titanium dioxide in the composition of cement-silicate paint provides self-cleaning of the painted coating due to photocatalytic reactions on the contaminated surface

Evaluation of self-cleaning performance of TiO2-intermixed and TiO2-coated cement mortars under natural sunlight

Self-cleaning cementitious materials have gained significant attention due to urban environmental pollution. In this study, nano-TiO2 (NT) was first mixed with cement mortar. Second, NTs were coated on fresh cast mortars and on hardened surfaces. Photocatalytic efficiency was evaluated using Rhodamine B under natural sunlight with three types of cement: white Portland (WPC), ordinary Portland (OPC), and Portland pozzolana cement (PPC). Among them, PPC cement mortars exhibited superior photocatalytic performance compared to WPC and OPC even with lower dosages of NT. The order of photocatalytic efficiency was highest for the hard-coat followed by fresh-coat and then intermix sample. Furthermore, Rietveld analysis for crystal structure refinement was used, and crystallography analysis (VESTA software) confirmed the presence of specific atoms and bonds in the crystal structure of PPC with NT. Microstructural analysis using XRD, SEM, and EDAX revealed underlying structural changes and thus quantified the hydration products.

Use of creep and recovery protocol to assess the printability of fibre-reinforced 3D printed white Portland cement composites

ABSTRACT White Portland cement is an ideal choice for producing 3D printed coloured composites due to its inherent whiteness. However, the uncontrollable rheological properties limit the establishment of printed structures and thus affect the mechanical properties. In this study, the polyvinyl alcohol (PVA) and polypropylene (PP) fibres were utilised as reinforcement materials in 3D printed white Portland cement composites (WPCCs) to improve the printability and toughness by controlling creep properties, aiming to build better printed structures. Experimental results show that the addition of PVA and PP fibres effectively improve the creep properties of WPCCs, and printed structures can be well built by controlling creep properties. Specifically, the thixotropy of WPCCs with PVA and PP fibre is improved within specific content ranges of 0∼1% and 0.4∼0.8%, respectively. Compared with reference sample, the flexural strength increases by approximately 148.8% and 90.2% when the PVA and PP fibre contents reach 1.25% and 1%, respectively.

Effect of White-Portland cement containing micro and nano silica on the mechanical and freeze-thaw properties of self compacting mortars

This study concentrated to investigate the influences of white-Portland cement (W-PC) containing silica fume (SF: micro-silica (µSi) and nano-silica (nSi)) as replacement (2–4 wt%) on mechanical (strength and durability), physical and microstructural behaviors of self-compacting mortars (SCMs) fabricated at 0.48–0.63 w/b ratios. In keeping with these purposes, besides of carrying out the workability (mini-slump flow: M−SF and V-funnel: V-F) experiments of SCMs, the mechanical and microstructural tests implemented were: unconfined compressive strength (UCS), flexural strength (FS), freeze–thaw (F-T) and scanning electron microscope (SEM) analysis. The outcomes displayed that, in comparison with the control, replacing W-PC by SF (particularly nSi) enhanced the UCS and FS, resisted against F-T durability by lowering the strength losses in UCS and FS. The ameliorated microstructure resulting in a reduction in the number and/or a narrowing in the size of micro-cracks and pores contributed to generate a more compact and consolidated SCM structure for the improving of strength and durability due of pore-filling effect and superior pozzolanic characteristics of µSi and especially nSi, this in turn reduced the permeability of SCM, which has a significant effect on the strength and durability behaviors of the SCM.

Chemical and physical properties of radiopaque Portland cement formulation with reduced particle size.

This study compared the chemical and physical properties of an experimental radiopaque white Portland cement (REPC) with reduced particle size to ProRoot white mineral trioxide aggregate (WMTA). The particle size distribution of experimental Portland cement (EPC) was examined, and then nano-zirconium oxide (nano-ZrO) was added to produce REPC. Chemical analysis, initial setting time, pH values, and push-out bond strength were evaluated. Results showed that REPC had smallest particle size (354.5±26.45 nm), while PC had the largest (1,309.67±60.54 nm) (p<0.05). Differences in chemical composition were observed. REPC exhibited shorter setting time (32.7±0.58 min) compared to WMTA (131.67±2.89 min) and PC (163.33±2.89 min) (p<0.05). All groups showed alkaline pH (p<0.05). REPC demonstrated the highest push-out bond strength (22.24±4.33 MPa) compared with WMTA (15.53±3.26 MPa) and PC (16.8±5.43 MPa) (p<0.05). This cost-effective PC formulation reduced the setting time and increased the push-out bond strength while maintaining the alkaline properties of the original cements.

A Study on the Understanding and Application of White Portland Cement

Research direction of Cement manufacturers is that the trend of high-performance clinker production, which has increased the content of Alite (C&lt;sub&gt;3&lt;/sub&gt;S) that dominate the initial strength of cement is intensifying. The content of Ferrite(C&lt;sub&gt;4&lt;/sub&gt;AF) mineral of White Portland Cement is less than 1%. In the case of White Portland Cement, when applied to concrete, it is free to choose the color of the concrete structure and exhibits excellent aesthetics and reflectance, so it is highly valuable as an architectural and civil engineering material, but it has a disadvantage of being more expensive than Ordinary Portland Cement, and there is a limit to using the circulating resources used in Cement clinker firing process to express white. The characteristics and color differences of cement differ depending on the difference between the raw material and the manufacturing method. When manufacturing white cement, fuel used to implement white and materials with low heavy metals such as Fe, Cr, and Mn in the raw material are used, cooled to a reducing atmosphere and the cooling method produces white cement clinker by water cooling. Even in process facilities, more careful selection is required when selecting materials for grinding facilities and refractories in the firing process.

Retracted: Effect of Grey and White Portland Cement Fillers on Flexural and Shear Strength of GFRP Composite Material

Retracted: Effect of Grey and White Portland Cement Fillers on Flexural and Shear Strength of GFRP Composite Material

Effect of Incorporating Titanium Dioxide Nanoparticles into White Portland Cement, White Mineral Trioxide Aggregate, and Calcium Enriched Mixture Cement on the Push-out Bond Strength to Furcal Area Dentin.

Bond strength of furcation repair materials is an essential factor in clinical success. Studies on the effect of adding titanium dioxide (TiO2) nanoparticles on the push-out bond strength of commonly used endodontic cements for furcation perforation repair is limited. This study aimed to evaluate the effect of adding TiO2 nanoparticles to white Portland cement (PC), white mineral trioxide aggregate (MTA), and calcium enriched mixture cement (CEM) on their push-out bond strengths. In this in vitro study, 120 endodontically treated molars were assigned to six groups (n=20) based on the material used to repair the perforation. In three groups, the cements (white PC, white MTA, and CEM) were placed in pure form, and in the three remaining groups, 1 weight % of TiO2 was added. The push-out bond strength was measured using a universal testing machine at a strain rate of 0.5 mm/min. Data were analyzed using one-way ANOVA and post hoc Games-Howell test (p< 0.05). One-way ANOVA showed significant differences in the mean bond strength values between the six groups (p= 0.002). The post hoc Games-Howell test showed that the bond strengths in MTA+TiO2 and PC+TiO2 groups were significantly higher than those in MTA and PC groups, respectively. However, there was no significant difference in the bond strength between CEM and CEM+ TiO2 groups. The incorporation of TiO2 into MTA and PC increased their push-out bond strength. However, it did not affect the push-out bond strength of CEM cement.

COMPARATIVE ANALYSIS OF PORTLAND AND WHITE CEMENT IMPACT ON UNCONFINED COMPRESSIVE STRENGTH OF SOIL

Soil improvement plays a vital role in any engineering project, as the entire load from the superstructure is transmitted on the underlaying soil. Weaker soil increases foundation dimension, which is costly and soft soil generally causes difficulties on construction sites when it has low strength and low stiffness. Hence, in order to reduce cost and achieving better structural stability, soil must be stabilized with a mixture in order to achieve larger load carrying capacity. When soils fail to meet the geotechnical requirements, stabilizing the soil using cement is an essential process in geotechnical practice. Clay soil was stabilized in this study using white cement and regular Portland cement. White cement and Portland cement were collected and mixed with clay soil in amounts of 2%, 4%, 6%, 8%, and 10%. Soil tests such as grain size distribution, specific gravity test, unconfined compressive test, soil tests were performed on samples. The report includes field sampling, laboratory testing and engineering analysis and evaluation. From the result of unconfined compressive strength test, it is found that the addition of 6%, 8%, 10% of Portland cement and 10% of white cement increases the shear strength of the clay soil.

Optimization of seasonal tilt adjustment photovoltaic system in Karbala, Iraq, by using the albedo benefit

This study aims to identify a cost-effective method for enhancing incident irradiation on the collector plane. Two different orientations for photovoltaic (PV) systems have been considered. The PV system is installed with albedo (0.25) on a concrete surface. The system is an off-grid with 690 Wp power, used for office applications with a yearly energy (1068) Khp/yr, located at Karbala Governorate /Iraq. The first orientation has an optimal seasonal tilt angle of 13o and 53o for summer and winter, respectively. In contrast, the second orientation is one-axis tracking, horizontal E-W axis, which produces more output power. To avoid the cost of using a tracking system and improve the amount of the output power of the first system, the old concrete surface of this system was treated with white Portland cement with a higher albedo value of 0.87 and then compared to the parameters (incident irradiation in the collector plane, transposition factor and the product available energy) with a second system. It was using Perez transposition model in PV syst software in this study. The results showed a higher value of comparing parameters when using inexpensive materials like white Portland cement, which improved the output PV system power than the tracking system.

The decisive role of the abrasion stress in concrete corrosion during acid attack – Comparison of resistance of different concrete types

Biogenic-produced sulfuric acid (BSA) attack, described as microbially induced concrete corrosion (MICC), reduces lifespan of concrete elements in sewage systems worldwide. Wastewater containing solids (e.g., sand) may cause abrasive stress to the concrete with increased flow intensity and thus accelerate the development of corrosion at the sewage/air interface in the tidal zone. The impact of drying and wetting cycles is also important; therefore, all these factors were included in the testing method. Overall, this paper evaluates the development and extent of corrosion after a pure chemical acid attack combined with a mechanical abrasion in the form of brushing. To simulate the wetting and drying cycles of corrosion, samples were partially immersed in an aggressive solution. The investigation comprised comparing the acid and abrasion resistance of three types of concretes – ordinary Portland cement concrete (OPC), sulfate-resistant concrete (SRC), and white ordinary Portland cement concrete (WOPC). The impact of abrasion on the individual parameters of corrosion, e.g., the amount of leached calcium, acid consumption, and damage depths, were also discussed. The results showed that mechanical abrasion in the form of brushing promotes acid penetration; however, there are differences depending on the type of concrete.

ULTRA-HIGH PERFORMANCE CONCRETES WITH PHENOLIC FOUNDRY SAND: MECHANICAL AND MICROSTRUCTURAL EVALUATION

In this investigation, the properties of ultra-high-performance concretes (UHPC) produced with different binders and aggregates were analyzed. Ternary and quaternary mixtures were tested, including structural white Portland cement (WPC), silica fume (SF), hydrated lime (HL), rice husk ash (RHA), fly ash (FA), and limestone filler (LF), in combination with industrial sand (IS) and discarded foundry phenolic sand (DFPS).&#x0D; The mixtures underwent two types of curing: moist curing until the testing age and moist combined with thermal curing. The concretes were evaluated for compressive strength and microstructure using thermogravimetric analysis (TG/DTG) and Fourier transform infrared spectroscopy (FTIR) techniques.&#x0D; The results showed that all mixtures achieved the desired levels of strength for UHPC (150 MPa). Up to 28 days, the mixtures with RHA exhibited higher strength compared to those with FA, regardless of the curing type. However, at 91 days, the mixtures with FA and thermal curing were more resistant than the mixtures with RHA. Among the quaternary mixtures, at 7 days, the strengths of the mixtures were equivalent, indicating that FA did not react at earlier ages.

СПОСОБЫ СИНТЕЗА СИЛИКАТСОДЕРЖАЩЕГО КЛИНКЕРА СТОМАТОЛОГИЧЕСКОГО ЦЕМЕНТА

The article provides an overview of modern cements used in dentistry with an emphasis on silicate cements such as mineral trioxide aggregate (MTA). The basic requirements for dental cements are given, including their safety, adhesion to tooth tissues, resistance to various influences and thermal properties. &#x0D; The article analyzes in detail the composition and properties of industrial white Portland cement used in construction, in comparison with the characteristics of dental silicate cements. The general issues of the synthesis of high-base calcium silicates used in dentistry are considered from the standpoint of the chemical technology of Portland cement. The mineralogical composition and hydration processes of various cement components, their effect on tooth color and other properties are discussed. &#x0D; The methods of reducing the temperature and increasing the rate of formation of calcium silicates, common in the technology of dental cements and in the production of Portland cement, are indicated. It is assumed that it is possible to accelerate solid-phase synthesis in the range of 1250-1350 °C with a special method of introducing mineralizers proposed at the V.G. Shukhov BSTU for the synthesis of white Portland cement, provided it is adapted for dental formulations.

Electrical and microstructural characterization of carbon nanotube-carbon fiber added cementitious conductive surface coating

In contrast to the traditional methods of directly adding conductive fillers to the cement matrix in the development of heatable conductive concrete, radiation shielding and smart sensing cementitious materials, this study proposes a more efficient approach by covering the non-conductive glass fiber reinforced concrete (GRC) surface with a thin conductive layer. Single-walled carbon fiber (SWCNT) and carbon fiber (CF) were used as conductive additives in the mixture of electrically conductive surface coating. Dosages of 0.1%, 0.2%, and 0.3% (wt) for SWCNT and 0.2%, 0.4%, 0.6%, 0.8%, and 1% (Vol) for CF were preferred. According to these ratios, a total of 15 different conductive cement coatings were carried out. White Portland cement and fine silica sand were used as binder and filler material, respectively. The conductive cement-based coating with a thickness of approximately 3 mm shows good adhesion and integration properties, since it is placed in the mold gradually at the same time as the GRC, which acts as the substrate. Resistivity, impedance, heatability (electrothermal), TGA-DTA and microstructure characterization were performed to investigate the electrical, thermal and microstructural properties of the coatings.The impedance/resistance properties of the cement-based composite samples containing CF showed superior performance compared to the other samples. In TGA/DTA analyses, the amount of CF in the cement mixture did not affect the thermal weightlossmuch. The lowest resistivity values were measured as 20 and 80 Ω.cm for the CF1.0 and CF0.8 samples, respectively, and the electrothermal test results showed that the temperature reached 45.5 and 28 °C from 23 °C, respectively, by applying 24 V voltage within 1 h with a power consumption of 750 W/m2 and 232 W/m2.