Compressive Strength Of Cement Research Articles

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.

Experimental Investigation to Enhance Oil Well Cement Compressive Strength by Using Nano Silica and Synthetic Fiber

The cementing process is one of the main and vital elements in the drilling and completion of oil and gas wells. Cement slurry design plays an essential role in cementing operations. Compressive strength, which represents a material's ability to sustain forceful conditions over time, is an essential property of oil well cement. This study provides an experimental investigation on the impact of coupled synthetic fiber and Nano Silica (nano-SiO2) on improving the compressive strength of Iraqi oil well cement class G. In addition, the results were compared to those of a previous study that utilized Nano Silica alone in conjunction with Iraqi oil well cement. The results indicated that the Iraqi oil well cement class G, after special additions, conforms to the specifications of the American Petroleum Institute (API). Results showed that adding synthetic fiber and Nano-Silica together significantly increased the compressive strength of Iraqi class G cement slurry cured at different conditions. Samples curing was done at 38°C and 60°C for 8 hours. The results indicated that the cement system with 1.5% by weight of cement (BWOC) of Nano-Silica and 1.5 gm of Synthetic Fiber increased the compressive strength by 50.38 and 39.92% at 38°C and 60°C, respectively. Through comparison with previous studies, it was found that the amounts of Nano Silica added to cement can be reduced by a large percentage when synthetic fibers are added with it, thus reducing the cost of using nanomaterials.

Effect of multi-walled carbon nanotube/Porous Carbon/SiO2 on reinforcing of cement mortar matrix: Modeling studies of effective parameters

The enhancement of the mechanical properties of cement composites by various nanomaterials is now a trendy subject. This study assessed the impact of three nanomaterials on the compressive and tensile strength of Portland cement mortar: biomass-derived porous carbon, MWCNT, and SiO2. These nanoparticles were developed using environmentally friendly, inexpensive technologies, and they underwent material characterization analyses using FESEM, N2 adsorption-desorption, contact angle, FTIR, XRD, and TEM. After 7 and 28 days, the compressive and tensile strength was assessed. According to the findings, among the samples, cement-SiO2 had the maximum compressive strength (19.32 MPa). The FESEM micrographs amply support the creation of the C-H-S gel and the presence of the bridge. The outcomes further showed that the nanoparticle's presence in the matrix does not significantly impact the tensile strength. SiO2-cement had the highest tensile strength, 1.45 MPa, matching the conclusions drawn from the compressive strength. Moreover, the compressive strength of cement was unaffected by the total pore volume of nanomaterials or the pore-filling mechanism of cement. Modeling (Linear regression-least square method) made it possible to predict the compressive strength for a period of 92 days and examine the influence of effective ingredients on it. Ultimately, the results indicate that porous carbon and silica can be viable alternatives for MWCNT.

Forecasting the strength of micro/nano silica in cementitious matrix by machine learning approaches

This work provides an intelligent machine learning-based technique for anticipating cement paste compressive strength incorporating nanocomposite. In this approach, artificial neural network (ANN), gene expression programming (GEP), random forest (RF), and ensemble approaches are used to combine multiple weak learners capable of identifying the mapping between input and output data into a robust learner. The accuracy of the strong learner as a whole will be increased by incorporating the weak learner with the least prediction error with enhanced correlation. The components of the cement paste mixture (such as water-to-cement ratio, nano-silica (%), micro-silica (%), curing time (days), and the compressive strength value are used as input data and output data. Thus, 205 datasets of cement compressive strength tests are collected to train and assess the learners. The reliability of the models was evaluated using cross-validation with K-folding and statistical error analysis (i.e., MAE, MAE, and RMSE). Therefore, interpretable methods using AdaBoost provide a significant correlation with a lower error rate of R2 = 0.96. The two that perform the best are ANN with ensemble Adaboost and RF with an R-square of 0.97. Additionally, the cross-validation findings demonstrate that the answer was correct and had minimal mistakes. The ensemble model, therefore, displays a strong connection. In addition, new expressions for the predictions of the 28-day compressive strength of nanocomposite containing silica content are developed based on the database. Sensitivity analysis reveals that curing time and silica content has a major influence on prediction. In addition, a model capable of predicting the values of the desired outputs when the necessary input parameters are provided is trained to generate the graphical user interface (GUI). It simplifies the procedure and provides a useful instrument for employing the model's civil engineering abilities.

Influence of graphene oxide on the self-healing of cement paste fractures in CCUS cementing: A combined analysis of experiments and molecular dynamics simulations

Cracking the cement paste for CCUS cementing can jeopardize the integrity of the wellbore, jeopardizing CO2 storage security. After carbonization and self-healing for 28 days, the experimental results indicate that cement's compressive strength growth rate combined with 0.10 wt% GO reached 1077%, whereas, in the control group, it reached only 850%. More CaCO3 crystals developed on the crack surface of GO cement as the carbonization self-healing time increased than in the control group. The self-healing volume of GO cement cracks was 74.3%, higher than the control group (34.5%). The molecular simulation results indicate that GO can enhance the capacity of cement-based materials to absorb CO2 and speed up CO2 diffusion. GO supplies nucleation sites for CaCO3 crystals and accelerates the carbonization self-healing process of cracks.

The Effect of Olive Waste on the Rheological Properties, Thickening Time, Permeability, and Strength of Oil Well Cement.

In the oil and gas industry, cementing is a very important process to maintain the stability of the well. The cement can provide an effective plug against fluid movement and at the same time supports the casing and formations. Based on the operation conditions, different types of additives are used to make the cement slurry, and incorporation of a new additive considerably affects all properties of the cement slurry and the solidified sheath. In this work, lab experiments were performed to investigate alteration of the Saudi Class G cement properties after incorporation of olive waste into the slurry, and the possibility of replacing the commercial retarder with olive waste was also studied in this work. Five samples with different olive waste content were prepared, and their rheological characteristics, thickening time, mechanical properties, and permeability were evaluated after 24 h of curing at 95 °C. The results indicated that olive waste could replace the use of a commercial retarder. The incorporation of olive waste did not affect the cement plastic viscosity, while the yield point, 10 s, and 10 min gel strengths of the cement were considerably increased with the increase in the olive waste content. The cement compressive strength was also increased with the incorporation of olive waste of a maximum of 0.375%, and the permeability decreased with the addition of a maximum of 0.25% olive waste.

Research on the Relationship between Pore Structure and the Compressive Strength of Oil-Well Cement

The integrity of wellbore cement is an important guarantee for the long-term safety and effectiveness of carbon dioxide geological storage. During the process of CO2 capture, utilization, and storage, construction factors will cause changes in temperature and pressure distribution, leading to changes in the pore structure of cement and a decline in compressive strength, which can easily cause the failure of cement ring integrity. To provide theoretical guidance and analysis methods for evaluating the mechanism of cement strength performance degradation and optimizing injection parameters, in this study, we conducted the following research based on relevant studies: (1) The fracture theory was revised based on the characteristic factors of oil-well cement; (2) a pore structure model was established to analyze the failure process of cement, clarifying the relationship between pore structure and the compressive strength of cement; (3) the parameters of the pore structure model were determined and analyzed, considering the influence of cement content and total porosity on the model, and finally, the regression parameter K value was determined to be 1600. This article can provide a useful reference for the research on the failure of cement rings in the CO2 injection process and other related studies.

Concrete powder waste as a substitution for Portland cement for environment-friendly cement production

The use of recycled concrete powder (RCP) as a supplementary cementitious material (SCM) to clinker may be an alternative for reducing emissions associated with Portland cement (PC) and the construction and demolition waste (CDW) disposal problem and is the aim of this study. The compressive strength at 28 and 91 days and CO2 emissions from Portland cement (PC) matrices with RCP replacement at 0%, 7%, 15%, and 25%, comminuted for 0, 0.5, 2, and 6 h were evaluated. The materials were characterized by X-ray diffraction (XRD), thermogravimetry (TG), X-ray fluorescence (XRF), laser granulometry, Blaine fineness, and specific mass. The results indicated the compressive strength of cement with 15% and 25% RCP as filler met the C40 and C32 class requirements of the Brazilian technical standard for cement, with the potential to mitigate CO2 emissions by up to 25%. The use of RCP in cement mortars indicated the potential for reducing binder consumption (kg.C.m−3.MPa−1) by 9% and carbon emissions (kg.CO2.m−3.MPa−1) by 8% at 91 days, showing to be a promising alternative for the production of environment-friendly cement.

Upcycling of textile and footwear wastes for synergistical reinforcement of cement mortar

The utilization of waste polymeric materials from textile, clothing and footwear (TCF) industry as aggregates in the cement is a valuable approach to reduce plastic pollution. However, the low modulus of polymers and poor interfacial interactions with the cement deteriorate their applications. Herein, we report an upcycling strategy for the recovery of waste fabrics and footwear sole materials from TCF industry as cement mortar reinforcement. The exfoliation of fabrics and pulverization of footwear soles enable them to expose the reactive groups which can absorb Ca2+ dissolved in water, thus helping the formation of C–H–S gel at the organic–inorganic interfacial transition zones between polymers and cement. It was determined by laser confocal Raman spectra. Hence, the exfoliated polyester fibers can prevent the crack expansion of cement and the devulcanized sole elastomers can dissipate energy while subjected to the external force, synergistically enhancing the mechanical properties. The flexural and compressive strengths of cement containing 0.5 wt% PFW and 5 wt% EPW are 48.9% and 59.6% higher than the neat cement. This work suggests a new strategy to realize value-added utilization of waste polymers which are difficult to be classified and separated.