Compressive Strength Of Cement Research Articles

Nanosilica Revolution: Unveiling the Impact on Enhancing Performance in Oil and Gas Well Cement

Summary In recent times, numerous oil and gas wells have experienced diverse failures ranging from downhole plug malfunctions to compromised wellbore integrity, resulting in damage to aquifers, loss of assets, and posing significant economic and environmental hazards. The inclusion of nanosilica into oil and gas well cement emerges as a promising solution, demonstrating a positive influence on enhancing mechanical properties, such as compressive strength and durability. This study investigates the impact of nanosilica on the mechanical properties of Class G Portland cement slurry, aiming to enhance its application in the oil and gas industry. The influence of nanosilica on the cement compressive strength behavior of oilwell cementing systems directly set and cured under the condition of 110°C and 2,000 psi is studied. Test results indicate that the cement slurries containing 3% nanosilica experienced compressive strength enhancement by 40% compared with the base sample after 24 hours. The compressive strength test results are corroborated by further evidence from a permeability test as well as microstructure analysis of the set cement. The thermal stability of the set cement samples using thermogravimetry analysis (TGA) concludes that the sample containing 3% nanosilica has the lowest mass loss. Future research should focus on long-term durability studies and comprehensive mechanical property assessments to further validate the benefits of these nanomaterials in real-world conditions.

Interfacial crack self-healing by Sporosarcina pasteurii: From medium optimization to spore encapsulation.

Self-healing cement takes advantage of microbial induced carbonate precipitation (MICP), a meritorious biological process, to achieve automatic healing of cement cracks. In this study, two beneficial factors, optimization of the bacteria culture medium and encapsulation of bacterial spores, were used to improve the MICP efficiency of Sporosarcina pasteurii in self-healing cement. On the one hand, in medium optimization, we compared the growth of Sporosarcina pasteurii fed with two generally used nitrogen sources, e.g., urea and ammonium chloride, and found that ammonium chloride can promote biomineralization more efficiently than urea. It was also confirmed that nickel (0.1 mg/l) and manganese ions (10 mg/l) benefit the MICP process through enhancement of urease activity and promotion of spore production. On the other hand, spores encapsulated in sodium alginate-gelatin gel beads prepared by using a flow nozzle device can have excellent swelling performance triggered by water. As an application demonstration, self-healing of cement cracks with consideration of the above beneficial factors was successfully verified without substantial influence on the cement compressive strength.

The Effect of Calcium Sulfate on the Hydration and Properties of Red Mud-Based Calcium Ferroaluminate Cement Clinker.

The hydration of high-alkali red mud-based ferroaluminate cement (RCFA) clinker with calcium sulfate needs to be regulated. This study explored the effects of the calcium sulfate type and dosage on the hydration and properties of high-alkali RCFA clinker. The research results show that when 4% gypsum was added, the 3 d compressive strength of cement was 39.1 MPa, and the 28 d compressive strength was 63.2 MPa. The 28 d strength increased by 61.6% compared with the 3 d strength. The properties of cement paste can be adversely affected by excessive anhydrite content. The exothermic hydration of clinker was accelerated by calcium sulfate at the beginning, but the rate declined as the process progressed. Sufficient sulfur supply can enhance the hydration of ye'elimite, thereby increasing the AFt content in the hydration product. The mass loss of the hydration product is mainly caused by the dehydration of ettringite, monosulfoaluminate, and AH3. In addition, the Na element in the RCFA hydration product is mainly present in monosulfoaluminate and unhydrated cement particles.

Machine learning based prediction of compressive and flexural strength of recycled plastic waste aggregate concrete

In the last 50 years, the use of plastics has increased significantly due to advances in technology, population growth and increasing needs. However, this trend has led to the accumulation of large amounts of plastic waste. Numerous studies have been conducted on the use of recycled plastic materials in concrete production as a means of recycling and environmental protection. This study aims to predict the 28-day cylinder compressive and flexural strength of concretes using Polyethylene Terephthalate (PET), Phenolic Formaldehyde (PF), Polypropylene (PP), Polycarbonate (PC), Polyvinyl Chloride (PCV), High-Impact Polystyrene (HIPS) and High-Density Polyethylene (HDPE) plastic waste as aggregates. In this scope, a comprehensive database was created using experimental results obtained from the literature. Then, this study used six ML models, including Support Vector Regressor (SVR), Random Forest Regressor (RFR), Gradient Boosting Regressor (GBR), XGBoost Regressor (XGR), LightGBM Regressor (LGR), Bagged Decision Trees Regressor (BDTR), to predict the compressive and flexural strength of recycled plastic waste aggregate concrete (RPWAC). From the experimental database, 253 data points with strength between 6.00–70.05 MPa were identified to estimate the compressive strength (CS) and 175 data points with strength between 1.21–7.96 MPa were identified for flexural strength (FS). Cross-validation was used for six ML models and hyperparameter fine-tuning was performed. The results showed that six different ML models predicted the compressive and flexural strengths of RPWAC with high accuracy. The XGR model predicted CS and FS better than the other five different models with R2 values of 0.931 and 0.999, respectively. The three main properties effecting the CS of RPWAC were plastic waste content, water/cement ratio and concrete specific gravity, while the three main properties affecting the FS of RPWAC were cement specific gravity, plastic waste content and cement CS.

New Insights Into Application Relevant Properties of Cu2+-Doped Brushite Cements.

Doping of brushite cements with metal ions can entail many positive effects on biological and physicochemical properties. Cu2+ ions are known to exhibit antibacterial properties and can additionally have different positive effects on cells as trace elements, whereas high Cu2+ concentrations are cytotoxic. For therapeutical applications of bone cement, a combination of good biocompatibility and sufficient mechanical properties is required. Therefore, the aim of this study was to investigate different physicochemical and biological aspects, relevant for application, of a brushite cement with Cu2+-doped β-tricalcium phosphate, monocalcium phosphate monohydrate and phytic acid as setting retarder. Additionally, the ion release was compared with a cement with citric acid as setting retarder. The investigated cements showed good injectability coefficients, as well as compressive strength values sufficient for application. Furthermore, no antibacterial effects were detected irrespective of the Cu2+ concentration or the bacterial strain. The cell experiments with eluate samples showed that the viability of MC3T3-E1 cells tended to decrease with increasing Cu2+ concentration in the cement. It is suggested that these biological responses are caused by the difference in the Cu2+ release from the hardened cement depending on the solvent medium. Furthermore, the cements showed a steady release of Cu2+ ions to a lesser extent in comparison with a cement with citric acid as setting retarder, where a burst release of Cu2+ was observed. In conclusion, despite the anticipated antibacterial effect of Cu2+-doped cements was lacking and mammalian cell viability was slightly affected, Cu2+-concentrations maintained the physicochemical properties as well as the compressive strength of cements and the slow ion release from cements produced with phytic acid is considered advantageous compared to citric acid-based formulations.

Evaluation of Machine Learning and Traditional Methods for Estimating Compressive Strength of UHPC

This research provides a comparative analysis of the optimization of ultra-high-performance concrete (UHPC) using artificial neural network (ANN) and response surface methodology (RSM). By using ANN and RSM, the yield of UHPC was modeled and optimized as a function of 22 independent variables, including cement content, cement compressive strength, cement type, cement strength class, fly-ash, slag, silica-fume, nano-silica, limestone powder, sand, coarse aggregates, maximum aggregate size, quartz powder, water, super-plasticizers, polystyrene fiber, polystyrene fiber diameter, polystyrene fiber length, steel fiber content, steel fiber diameter, steel fiber length, and curing time. Two statistical parameters were examined based on their modeling, i.e., determination coefficient (R2) and mean square error (MSE). ANN and RSM were evaluated for their predictive and generalization capabilities using a different dataset from previously published research. Results show that RSM is computationally efficient and easy to interpret, whereas ANN is more accurate at predicting UHPC characteristics due to its nonlinear interactions. Results show that the ANN model (R = 0.95 and R2 = 0.91) and RSM model (R = 0.94, and R2 = 0.90) can predict UHPC compressive strength. The prediction error for optimal yield using an ANN and RSM was 3.5% and 7%, respectively. According to the ANN model’s sensitivity analysis, cement and water have a significant impact on compressive strength.

Full‐Component Utilization of Cellulose Nanofibrils and Artificial Stone Waste for Cement Enhancement

With the concept of carbon neutrality, the value‐added utilization of biomass materials and solid waste becomes a cutting‐edge topic. Cellulose nanofibrils (CNFs) receive much attention due to their excellent properties in terms of high aspect ratio, specific strength, and specific surface area, but their large‐scale preparation remains a great challenge. Herein, a facile aqueous solution method is proposed for the fabrication of CNFs through artificial stone waste (ASW)‐assisted supramolecular interfacial interactions for the full‐component utilization in cement mortar materials. The strong hydrogen bonding interaction between ASW and CNFs can effectively prevent the intramolecular hydrogen bonding of CNFs and agglomeration of ASW, while improving the stability of CNF/ASW suspensions. The resulting CNFs/ASW with active hydroxyl or carboxyl group can improve the flexural and compressive strength of cement (30.8% and 37.8% higher than that of pristine cement, respectively) by embedding into the defects of cement mortar and promoting the hydration process of cement. In this work, not only a new idea is provided for the large‐scale preparation of biomass nanomaterials, but also the full‐component value‐added utilization of biomass and solid waste in cement materials is opened up.

Prediction PCC Cement Compressive Strength Based on Chemical Compounds and Physical Properties with Machine Learning Techniques

Prediction PCC Cement Compressive Strength Based on Chemical Compounds and Physical Properties with Machine Learning Techniques

Analysis of Pile Foundation for Hospital Buildings

Pile foundations are widely employed to provide support for bridges and various structures, ensuring the safe transfer of structural loads to the ground while preventing excessive settlement or lateral movement. They excel in transferring structural loads from weaker or compressible soil layers to the stronger, more stable soils and rocks beneath. Pile foundations constitute an integral component of a structure.  In this research work the foundation of the hospital (G+6) was design by the pile foundation. We have used M25 grade of concrete for the preparation of design mix. The characteristic strength and load bearing of soil was tested by Plate load test and other materials tested by slump cone test , aggregate Impact Value test cement compressive strength test (cement fineness test construction water PH value . The expected result of SBC is 20000kg approximate.  Project reports typically encompass introductions and problem definitions, along with literature reviews pertinent to the project. They detail the study area's location and the project site, as well as providing concise information about the equipment utilized on- site.  Additionally, it covers crucial tasks such as centerline marking, boring, reinforcement placement, concrete pouring, excavation, and chipping of pile caps.

Hybrid Machine Learning Model Based on GWO and PSO Optimization for Prediction of Oilwell Cement Compressive Strength under Acidic Corrosion

Hybrid Machine Learning Model Based on GWO and PSO Optimization for Prediction of Oilwell Cement Compressive Strength under Acidic Corrosion

Artificial Intelligence Models for Predicting the Compressive Strength of Geopolymer Cements

The utilization of nanosilica and cellulose nanocrystals (CNCs) in cement geopolymers remains challenged by intricacies and uncertainties regarding their concentration, posing difficulties in the formulation of systematic geopolymer mix designs. This study aims to formulate models based on Artificial Neural Networks (ANN) capable of forecasting the compressive strength of geopolymers through the utilization of experimentally acquired data. Nanosilica was applied at concentrations of 2%–4% and CNCs at 1%–3%. ANN was modeled using MATLAB to predict the compressive strength of the geopolymer. The results indicated an effect of nanosilica and CNCs on the compressive strength of geopolymer at 2%–4% concentration and 1%–3% CNCs. The best ANN was the GDX training function, purelin activation function, LGD and LGDM learning functions, Lr 0.1 and 0.01 at the number of epochs 3812 out of 25000 and 1774 out of 25000, resulting in the best correlation values of 0.994 and 0.959; the lowest RMSE values are 0.022 and 0.110. The results of the ANN model built based on actual data prove that the model is helpful for accurate simulation to predict the compressive strength of geopolymer cement. This study contributes novelty by optimizing the design model for Geopolymer Cements incorporating nanosilica and CNCs. Doi: 10.28991/CEJ-SP2024-010-03 Full Text: PDF

Characterisation of cement loaded with magnetically aligned nano-magnetite

In this study, the effect on the compressive strength of cement with the addition of 1–5 wt% nano-magnetite particles (nano-Fe3O4) is identified at the age of 7 days and 28 days of curing. In addition, an approach of aligning these nano-magnetite particles within cement using an external magnetic field is presented, where the orientation of nano-magnetite particles is aligned parallel to the compressive load. The effect of the compressive strength on cement mortar with the aligned nano-magnetite particles is compared with the non-aligned samples. Both aligned and non-aligned samples show positive effects on the compressive strengths as compared to the control samples, where the cement mortar with aligned nano-magnetite shows significant improvement on compressive strength up to 21%. This study also shows that the addition of 3 wt% nano-magnetite particles to cement mortar is the optimal amount to achieve maximum enhancement of compressive strengths.

Preparation of a Polycarboxylate Superplasticizer with Different Monomer Regulations and Its Effect on Fluidity, Rheology, and Strength of Cement.

Polycarboxylate superplasticizers (PCEs) are indispensable functional ingredients in modern construction, and their usage is extensive. Herein, a polyether macromonomer (VPEG) with high reactivity was used to prepare VAPCEs with different interfacial adsorption properties (acid-ether ratio) at low temperatures and reacted in 30 min. The effects of various VAPCEs on the fluidity, rheology, and strength of cement were investigated with a w/c (water/cement) ratio of 0.35. Results showed that VAPCE-3 (acid-ether ratio is 3) exhibited the best dispersion, and the fluidity of cement slurry with VAPCE-3 (280 mm) is 278.38% higher than that of the control sample (74 mm). The reason is summarized as VAPCE-3 having good adsorption performance on the surface of cement particles and having a large steric hindrance between particles. The compressive strength of cement with VAPCE-3 was enhanced by 8.29% compared with pure cement in 3 days of curing age due to its densification on microstructure and lowest R orientation index of calcium hydroxide. With the amount of acrylic acid in VAPCE increasing, the flexural strength enhanced because a more cross-linking network was formed with Ca2+ in cement with the increase of COO- content in VAPCEs.

Novel material to enhance the integrity of CCUS cement sheath: Exploration and application of calcium aluminate cement

Carbon dioxide (CO2) emissions are being reduced using the technique known as CCUS (Carbon Capture, Utilization, and Storage). At present, cementing cement paste based on ordinary silicate cement (OPC) and compounded with CO2 corrosion-resistant materials are often used in CCUS wells. CAC cement is characterised by low alkaline hydration content and its study in CCUS wells has rarely been reported. Therefore, CAC cement will be a new cement material for CCUS wells. In this study, we have developed an experimental device to simulate the working conditions of CCUS based on the actual well conditions of CCUS and investigated the effects of stress-coupled CO2 corrosion environment on the performance of CAC cement. According to the experimental findings, CAC cement's compressive strength degraded at a rate of 30.6% after 60 days of CO2 corrosion, which was lower than that of OPC cement (38.3%). When compared to OPC cement, the peak strain and stress of CAC cement increased by 57.2% and 7.85%, respectively. Furthermore, compared to OPC cement sheath, the CAC cement sheath's bearing capacity increased by 8 MPa after stress corrosion, and the crack area of the CAC cement sheath after failure was considerably smaller at 275 mm3 than at 735 mm3. Additionally, after being subjected to stress-coupled CO2 corrosion, the integrity of the CAC cement sheath was much superior to that of the OPC cement sheath, offering a fresh viewpoint for building CCUS cement slurry systems.

Effect of Coffee Grounds/Coffee Ground Biochar on Cement Hydration and Adsorption Properties.

Taking advantage of the strong adsorption characteristics of coffee grounds (CGs) and coffee ground biochar (CGB), this research employed equal amounts of 2%, 4%, 6%, and 8% CGs and CGB to replace cement. This study thereby examined the impacts of CGs and CGB on cement compressive strength, as well as their abilities to adsorb chloride ions and formaldehyde. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTG), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were employed to investigate the hydration mechanism and characterize the microscopic structure. The results show the following: (1) The presence of a substantial quantity of organic compounds in CGs is found to have an adverse effect on both the compressive strength and hydration degree of the sample. The use of CGB after high-temperature pyrolysis of phosphoric acid can effectively improve the negative impact of organic compounds on the sample. (2) The addition of CGs reduces the adsorption of chloride ions by cement, primarily due to the presence of fewer hydration products. However, when CGB was incorporated into cement, it enhanced the ability to adsorb chloride ions. (3) Cement containing 8% CGB content can slightly enhance the adsorption of formaldehyde. However, the cement sample with 8% CGB content exhibited the most significant ability to adsorb formaldehyde.

Sustainable technologies of leather wastes: An eco-friendly oily acrylic resin-reinforced collagen polypeptide-based foaming agent for the green processing of foam concrete

In this research, a new eco-friendly collagen polypeptide-based foaming agent (CPFC) was prepared via a hydrophobic grafting modification of the collagen polypeptide (CP) from oily acrylic resin, in which the CP was extracted from leather wastes. The molecular structure of CPFC was characterized by FTIR, TGA, XRD, and laser particle size tests. The results showed that the oily acrylic acid molecular chain segments effectively copolymerized with CP, improving the hydrophilic and lipophilic balance of CP molecules. Given the increase of acrylic resin content in CPFC, the surface tension of CPFC at the critical micelle concentration gradually decreased and tended toward the critical value (30 mN/m). The foamability and foaming multiple of 9-CPFC and 7-CPFC reached 535 mL and 31.89 times, respectively. Next, we prepared a CPFC-based foam concrete with a dry density of 500 Kg/m3 via compounding a mechanical CPFC foaming agent with concrete. The resulting CPFC-based foam concrete was then characterized using a universal testing machine, thermal conductivity meter, ultra-depth 3d microscope, and other analysis techniques. The results indicated that the 5-CPFC foam concrete possessed good foam stability and compatibility. Moreover, the pore size distribution of the foam concrete was uniform, showing a less stringy pore structure, and the water absorption rate and thermal conductivity levels were 27.8 % and 0.61 W/m·K, respectively. The compressive strength of cement was approximately 1.37 MPa, which exceeds the national standard. Moreover, it was found that the CPFC possessed certain retarding properties that were similar to cement, suggesting that it is a highly suitable additive for foam concrete.

Stabilization of Fluidic Silty Sands with Cement and Steel Slag

Fluidic silty sand is often difficult to use directly in engineering construction because of its low strength and plasticity index. This study employed steel slag to replace part of the cement in silty sand stabilization to broaden the feasibility of resource recycling and to reduce the construction cost and carbon emissions in engineering practices. A series of indoor tests investigated the influences of the cement/steel slag ratio, initial water content, curing age, and temperature on the compressive strength of cement- and steel slag-stabilized fluidic silty sands (CSFSSs). Their stabilization mechanism was discussed via microstructural observation and spectral analysis. The results showed that the most economical cement/steel slag ratio could be 9:6, saving 40% of cement and not changing with the initial water content. The compressive strength of the CSFSSs decreased with the initial water content and increased rapidly and then slowly over the curing age. The curing temperature had a positive impact on their strength growth. The microstructure characteristics and spectral analysis showed that adding steel slag indeed affected the formation of gels in the cement-stabilized fluidic silty sands. This study could reference the application of CSFSSs in engineering practices.

Study on effects of metakaolin on the silica-cement slurry performance under ultra-high temperature conditions

In oil and gas exploration and development, the complex working conditions of high temperature and high pressure are increasing, and the strength decline of silica-cement often occurs under such conditions. In this work, the metakaolin influence on the mechanical properties and micro-structure of silica-cement at 240 ℃ and 21 MPa condition is comprehensively studied. XRD technique investigated the chemical composition of cement crystal phase, and SEM observed the micro-morphology of high temperature cement. Results showed that the loading metakaolin has reduced porosity by 12.86%, air permeability while greatly increased nanopore (＜50nm) by 36.47% and increased nanopore (＜10 nm) by 10.34%. Thus, the cement permeability reduced greatly or its anti-channelling enhanced, that is, such results improved the comprehensive performance of cement slurry. These observations, combined with the previously reported the remarkable enhancement of the MK cement compressive strength, represent a major step toward the development of strength retrogression-resistant material at high temperature.

The Effects of Corrugated Steel Fiber on the Properties of Ultra-High Performance Concrete of Different Strength Levels

This article describes the influence of corrugated steel fiber on the mechanical properties and fracture energy of Ultra-High Performance Concretes (UHPC) of various strength levels. Three UHPC formulations with compressive strengths of 143, 152, and 177 MPa were tested. The following parameters for the formulations without fiber and those containing 2% steel fiber by volume were determined: compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, Poisson’s ratio and critical stress intensity factor. From the axial tensile test results, the following parameters were obtained: the cracking stress, tensile strength, and fracture energy of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) of different strength levels. With the introduction of steel fiber, an increase in all the investigated parameters is observed regardless of the strength of the concrete matrix. The most remarkable influence the fiber has on the splitting tensile strength, flexural strength and critical stress intensity coefficient, the increase is up to 1.6–3.2 times. There was a slight increase in compressive strength and elastic modulus—up to 5.0–7.4% depending on the composition. Poisson’s ratio was equal to 0.2 regardless of the strength of the concrete matrix and the presence of steel fiber. Based on the test results, equations were proposed to predict the properties of UHPC and UHPFRC depending on the water–cement ratio, silica fume content, cement compressive strength and the volumetric content of corrugated steel fiber. The calculated and experimental values showed good convergence with a correlation coefficient in the range of 0.885–0.997.

Comparative study on the environmental impact of Portland cement paste that mixed with naphthalene or carboxylate based polymer solutions

The environmental impact is now a valuable coefficient for any human activity. The effect of solar UV radiation on the cement samples was limited and contained in the thin surface layer of the samples. In general, viscocrete was the most effective in protecting cement against solar ultraviolet radiation, where cement samples treated with the two polymers used separately showed greater compressive strength values than those recorded for samples treated with sikament polymer. This study is important since the mechanical properties of cement and concrete at early stages are important in the field of civil engineering. The effect of soaking in water on the ability of the cement to withstand the pressure on it was also studied, and several physical measurements were applied to samples of untreated cement and samples mixed with the mentioned polymers. These measurements included measuring the porosity, density, and total dissolved solids by X-ray diffraction, FTIR, and line scan EDX. These measurements were carried out on cement samples before, after, after soaking in water, as well as on cement samples mixed with polymers. The measurements were extended to the soaking water. So, adding two types of polymers (Sikament and Viscocrete) separately to cement could protect concrete constructions against serious environmental impacts. The EDX analysis of the samples used in this study showed that the Egyptian sources of raw materials used in the cement industry are rich sources of rare chemical elements. The importance of adding two types of polymers, Sikament and ViscoCrete, separately to cement protects concrete construction against environmental impacts, which is our main highlight, significance, and advice of this work. Decrease the water reduction percentage and increase the compressive strength for portend cement paste to 0.5 % viscocrete using 15 W and 30 W UV lamps, with a maximum value of 127.52 MPa for 0.5 % viscocrete at the 30 W lamp. Higher UV lamp exposure at 45-watt lamp decreases the compressive strength after exposure than others. The total porosity percentage of all used percentages of Sikament polymer addition is greater than that using viscocrete polymer with a 0.75 % Sikament high value of 7.60 (total porosity) TP%. The conductivity EC of the cement treated with polymer samples shows a smaller increase in the case of viscocrete polymer than that of Sikament, with a value of 404 uS using 0.5 % and 0.75 % viscocrete, which is supported by TdS measurements with values of 202 ppm for 0.5 % and 0.75 % viscocrete, respectively. The EDX results for cement polymer mixtures prove that both polymers used extract many elements from the cement paste and protect human beings from their dangers, like Sb, Na, Zr, Hf, Rb, Mo., Ti, P, Cu, Er, Cl, In, and Te,Te with greater efficiency for the Viscocrete polymer than the Sikament one. Many factors affecting the cement's compressive strength and mechanical properties are the innovation of this work, which deals with the impact of some materials affecting it. The main target is to discuss the effect of different polymers on some properties of cement paste. Other properties can be discussed in near future, like the void volume effect, packing density, Van der Waals volume, and apparent molar volumes. The polymer contents have the largest effect on increasing the compressive strength of cement paste, followed by the w/c ratio and curing time.