Different Types Of Cement Research Articles

Mechanical Characteristics of Hardened Concrete with Different Types of Cement and Aggregate Available in Bangladesh

This paper presents the results of an investigation on the influence of aggregate and binding material type on the mechanical properties of hardened concrete. To perform this investigation, four different types of coarse aggregate (Brick Aggregate, Recycled Brick Aggregate, Black Stone and Shingles) and eight types of binding material [Ordinary Portland Cement (OPC), CEM Type II B-M, CEM Type II B-M-SL, 40% OPC – 60% Slag CEM IIIA, 80% OPC – 20% Slag(CEM II/A-S), 70% OPC – 30% Slag(CEM II/B-S), 30% OPC –70% Slag(CEM-IIIB), 15% OPC –85% Slag(CEM-IIIC)] have been used. Aggregates were collected and prepared according to grading requirements of ASTM C33-03. Several tests as specific gravity, absorption capacity, unit weight and abrasion resistance were performed for coarse aggregate. Cylindrical concrete specimens of diameter 100 mm and length 200 mm were made with different W/C ratio (0.45 and 0.5) and cement content (340 kg/m3 and 400 kg/m3). A total of 42 different cases were considered for testing. The specimens were tested for compressive strength, stress-strain curve and Young’s modulus at the age of 28 days. Non-destructive test as Ultrasonic Pulse Velocity (UPV) were also performed. To conduct UPV test Portable Ultrasonic Non-destructive Digital Indicating Tester (PUNDIT) were used. The major objective of this study was to investigate the mechanical characteristics of concrete for different types of aggregate and binding materials. The significance of those results is discussed here.

Influence of Dregs Waste on the Alkali–Silica Reaction: A Comparative Analysis among Different Types of Cement

Influence of Dregs Waste on the Alkali–Silica Reaction: A Comparative Analysis among Different Types of Cement

Assessment of Natural Radioactivity in Cements (Local and Imported) in Mali

<i>Background</i>: In this article, the radioactivity concentrations of U-238, Th-232 and K-40 (NORM) and radiological hazard parameters in different types of cements commonly used in Mali and available on the Malian market have been analyzed. The obtained values of NORM concentrations and radiological hazards in seven (07) cements samples will permit to the AMARAP to estimate the exposure (gamma rays) from the buildings and dwellings made by these cements. It will permit also to determine any over exposure (determinist effects which are an immediate tissue reaction due to the high exposition of ionizing radiation) and minimize as well the associated risk due to low doses (stochastic effects). <i>Materials and Methods</i>: The health impact due to the exposure of radionuclides from these cements was evaluated by the determination of specific activity of radionuclides U-238, Th-232 and K-40 using gamma spectrometry analysis. The radiological hazards such as Absorbed Dose Rate (Ḋ) Annual Effective Dose (Ė) Internal and External Dose indexes (H<sub>in</sub> and H<sub>ex</sub>) were evaluated in these cements samples. <i>Results</i>: The range of specific activities for U-238 vary from 21.77 ± 1.50 to 145.31 ± 7.70 Bq/kg, for Th-232 from 8.85 ± 0.52 to 73.56 ± 3.82 Bq/kg and for K-40 from 104.27 ± 5.63 to 351.97 ± 18.08 Bq/kg. The peak of U-238 wasn’t detected only in one (01) sample (CIM04). The highest value of specific activity was reported in sample CIM07 (DANGOTE). The values of radiological hazard such as Ḋ, Ė, H<sub>in</sub> and H<sub>ex</sub> from this work were within the dose criteria limits given by international organizations (ICRP and UNSCEAR) and national standards. <i>Conclusion</i>: This study shows the analyzed cements do not pose any significant source of radiation hazard and are safe for use in the construction of dwellings even if the risk (stochastic effect) associated with low dose exists. Special attention and more analyzes must be done on them for more protection of public health.

Clinical Outcome of Prefabricated Zirconia Crowns Cemented with Self-Adhesive Resin and Pure Glass Ionomer on Primary Teeth: A Retrospective Cohort Study.

Retentive strength data are critical to predicting the long-term clinical performance of zirconia crowns for primary teeth. Objectives: This research assessed the clinical outcome of prefabricated zirconia crowns (PZCs) cemented with either self-adhesive resin cement or pure glass ionomer cement in the primary teeth of children. Method: In the present research, a sample of 162 prefabricated zirconia crowns were collected through convenience sampling. A follow-up examination was conducted at 12 and 24 months to assess the clinical outcomes of PZCs post cementation. Results: Zirconia crowns cemented with self-adhesive resin showed high clinical outcomes at both 12 and 24 months, with 95.1% of crowns retained. In contrast, crowns cemented with glass ionomer cement had slightly lower clinical outcomes, with 91.4% retained at 12 months and 84.0% retained at 24 months, indicating a significant difference (p-value). Long-term follow-up is crucial for the optimal maintenance of crown stability. Conclusions: Self-adhesive resin cement is a viable option for cementing PZCs in pediatric dentistry, demonstrating satisfactory clinical performance over both 12 and 24 months. Future studies comparing different types of cement are recommended for further validation of these results.

Performance of cementitious systems containing calcined clay in a chloride-rich environment: a review by TC-282 CCL

In this review by TC- 282 CCL, a comprehensive examination of various facets of chloride ingress in calcined clay-based concrete in aggressive chloride-rich environments is presented due to its significance in making reinforced concrete structures susceptible to chloride-induced corrosion damages. The review presents a summary of available literature focusing on materials characteristics influencing the chloride resistance of calcined clay-based concrete, such as different clay purity, kaolinite content and other clay minerals, underscoring the significance of pore refinement, pore solution composition, and chloride binding mechanisms. Further, the studies dealing with the performance at the concrete scale, with a particular emphasis on transport properties, curing methods, and mix design, are highlighted. Benchmarking calcined clay mixes with fly ash or slag-based concrete mixes that are widely used in aggressive chloride conditions instead of OPC is recommended. Such comparison could extend the usage of calcined clay as a performance-enhancing mineral admixture in the form of calcined clay or LC2 (limestone-calcined clay). The chloride diffusion coefficient in calcined clay concrete is reported to be significantly lower (about 5–10 times in most literature available so far) compared to OPC, and even lower compared to fly ash and slag-based concrete at early curing ages reported across recent literature made with different types of cements and concrete mixes. Limited studies dealing with reinforcement corrosion point out that calcined clay delays corrosion initiation and reduces corrosion rates despite the reduction in critical chloride threshold. Most of these results on corrosion performance are mainly from laboratory studies and warrant field evaluation in future. Finally, two case studies demonstrating the application of calcined clay-based concrete in real-world marine exposure conditions are discussed to showcase the promising potential of employing low-purity calcined clay-based concrete for reducing carbon footprint and improving durability performance in chloride exposure.

Self-Leveling Mortars Produced with Different Types of Cement: Physical–Mechanical Properties and Carbon Emissions

Self-Leveling Mortars Produced with Different Types of Cement: Physical–Mechanical Properties and Carbon Emissions

Comparative Study on Flexural Behavior of Reinforced Concrete Beams Cast by Using Hydraulic Cement and Ordinary Portland Cement

This paper is a comparative study of the flexural behavior of reinforced concrete beams cast by using hydraulic cement and ordinary Portland cement for construction applications. The main variables used in this research comprise of type of cement, ultimate compressive strength of concretes, and curing time. Two different types of cement, including hydraulic cement and ordinary Portland cement, were used at three different ultimate compressive strengths of 18 MPa, 25 MPa, and 32 MPa with the curing times of 28 and 90 days. The beams' nominal span-to-depth (L/h) ratio is 8.0. The results showed that the reinforced concrete beams cast by using hydraulic cement and ordinary Portland cement had similar flexural behavior and failure patterns. Both types of the reinforced concrete beams exhibit linear elastic behavior up to approximately 80–90% of their maximum applied load. Then, the behavior of the beams is nonlinear in that the deflection increased rapidly with a slight increase in the applied load until reaching their failure. In addition, based on the experimental results obtained from this study, it was found that the ACI design equations are acceptable for predicting the design strength of the reinforced concrete beams cast by using hydraulic cement and the hydraulic cement can be an equivalent substitute for ordinary Portland cement for the reinforced concrete beams used in this study. Therefore, this application of the hydraulic cement is not only the environmentally friendly practices, but also promoting low-carbon society as well.

Analysis of PCE-based Superplasticiser for the Different Types of Cement using Marsh Cone Test

Analysis of PCE-based Superplasticiser for the Different Types of Cement using Marsh Cone Test

Evaluation of sulfuric acid effect on bending strength of steel used in concrete reinforcement in sanitation structures

Most sanitation structures in the world are constructed using concrete which is reinforced by the steel, this type of concrete is called Reinforced Cement Concrete (RCC). The RCC structure is believed to be relatively resistant to corrosion which the sanitation structures are prone to due to the aggressive environment in which they are subjected to. This belief has been compromised since the reinforced concrete used in the sanitation structures such as the concrete sewer pipes has become susceptible to Microbiologically Induced Deterioration (MID). This MID leads to degradation and compromised strength and service life of the RCC. In the reinforced concrete structure, the backbone of this structure is the reinforcing steel which when its strength is compromised by the MID, the whole structure is compromised. The present research therefore aimed at evaluating the effects of sulfuric acid, resulting from the MID process, on the bending strength of steel metal used for reinforcing concrete in sanitation structures. Reinforced concrete specimens were developed using different types of cement and different concrete cover. The three different types of cement were, Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC) and Limestone Calcined Clay Cement (LC3), while concrete covers of 15mm and 25mm were applied. They were then subjected to a harsh environment (a sample of sewage) suitable for corrosion just like in their actual operational environment. To determine the effects of sulfuric acid resulting from MID on the steel metal, the steel metal was tested using a Universal Testing Machine (UTM). The bending strengths before and after being subjected to an aggressive environment were determined. The testing of the specimens was done at an interval of 14 days for a period of three (3) months. According to the results, for a concrete cover of 25mm, LC3 showed a minimum percentage reduction in strength compared to PPC and OPC. It had the lowest percentage reduction in strength after 84 days which was 5.25%, OPC 7.20%, and PPC 7.24%. In conclusion, there was a strength reduction for all specimens tested. LC3 showed good resistance to the effects of MID compared to PPC and OPC. In terms of concrete cover, 25mm showed good resistance to MID compared to 15mm concrete cover.

Effect of cement type on vertical marginal discrepancy and residual excess cement in screwmentable and cementable implant-supported monolithic zirconia crowns.

The purpose of this study was to investigate the vertical marginal discrepancy (VMD) and residual excess cement (REC) of cementable and screwmentable monolithic zirconia crowns cemented with different types of cement. Abutments were attached to 40 implant analogues. Crowns were created using computer-aided design/computer-aided manufacturing technology from monolithic zirconia blocks, either with or without a screw access hole (SAC). Crowns created both ways were split into two groups and cemented with resin and zinc polycarboxylate cement under a 5-kg weight. VMD and REC values were evaluated using an X20 zoom stereomicroscope. Data were analysed using two-way ANOVA and the Bonferroni test. According to the two-way ANOVA results, REC measurements differed significantly in the crown design and cement groups. However, whilst VMD values were significantly different in both crown design groups, there was no significant difference in the cement groups. According to the Bonferroni test results, the highest REC (157.241 ± 44.29µm) and VMD (68.052 ± 16.19µm) values were found in the crowns without SAC and cemented with zinc polycarboxylate. Screwmentable crowns are more effective than cementable crowns in reducing REC and VMD. Whilst polycarboxylate cement reduces VMD in screwmentable crowns, resin cement is more suitable for cementable crowns.

Forecasting maximum formwork pressure for self-compacting concrete using ARX-Laguerre machine learning model

Forecasting the maximum pressure exerted by cast-in-place self-compacting concrete (SCC) is a major concern for formwork designers, researchers, and site engineers to accurately design the bearing capacity of the formwork and control the casting rate for safe and fast construction. This article aims to utilize the ARX-Laguerre model, which is a data-driven model to forecast the maximum form pressure. A laboratory instrumented setup was used to cast a 2-m column using SCC made with two different types of cement. A pressure system consisting of four sensors was used to document the pressure during casting. The data were sent to the cloud at every 1-min interval for real-time monitoring. The data were used to develop the model. The results demonstrated that forecasting with the ARX-Laguerre model is highly accurate. The model can forecast the maximum pressure exerted by SCC with less complexity. The model performance was also found to be consistent with insignificant differences between actual experimental results and predicted results. With a recursive and straightforward representation, the resulting model, known as the ARX-Laguerre model, ensures the parameter number reduction. Providing fast prediction of the maximum pressure. The model enables formwork designers to forecast the form pressure to design safe formwork and also helps to control the casting rate when SCC is used.

An Industrial Control System for Cement Sulfates Content Using a Feedforward and Feedback Mechanism

This study examines the design and long-term implementation of a feedforward and feedback (FF–FB) mechanism in a control system for cement sulfates applied to all types of cement produced in two mills at a production facility. We compared the results with those of a previous controller (SC) that operated in the same unit. The Shewhart charts of the annual SO3 mean values and the nonparametric Mann–Whitney test demonstrate that, for the FF–FB controller, the mean values more effectively approach the SO3 target than the older controller in two out of the three cement types. The s-charts for the annual standard deviation of all cement types and mills indicate that the ratio of the central lines of FF–FB to SC ranges from 0.39 to 0.59, representing a significant improvement. The application of the error propagation technique validates and explains these improvements. The effectiveness of the installed system is due to two main factors. The feedforward (FF) component tracks the set point of SO3 when the mill begins grinding a different type of cement, while the feedback (FB) component effectively attenuates the fluctuations in the sulfates of the raw materials.

Behavior of Potential of Half-Cell AISI 1018 and GS in Concrete Buried in Sand in the Presence of MgSO4

This project, in the area of reinforced concrete corrosion, evaluated the potential of half-cell AISI 1018 CS (Carbon Steel) and GS Steel (Steel with galvanized coating); 15 cm long bars were used as reinforcement in specimens of concrete buried in a Type SP Sand (contaminated with 0% and 3% MgSO4). The experimental arrangement of this research represents the case of the elements of the foundations of concrete structures that are planted near marine areas where this type of soil exists with the presence of high contents of depassivating ions such as sulfates. The study specimens were made with two concrete mixtures with a water/cement ratio 0.45 but with different types of cement (Portland Cement and Sulfate Resistant Cement). For monitoring the half-cell potential according to ASTM C 876-15, the specimens were buried in the clean SP soil and in the same soil but contaminated with MgSO4. After more than 270 days of exposure to uncontaminated SP sand contaminated with MgSO4, the behavior of the half-cell potentials or corrosion potentials show that the specimen made with the sulfate-resistant cement and reinforced with GS Steel (Steel with galvanized coating) presents the highest resistance to corrosion by MgSO4 at a concentration of 3%.

Phosphorus adsorption from aqueous solutions using different types of cement: kinetics, isotherms, and mechanisms.

Exploring low-cost and high-performance phosphorus (P) adsorbents is key to controlling P contamination in water. This study evaluated the P adsorption performance of three types of cement: Ordinary Portland cement (OPC), Portland slag cement (PSC), and Portland pozzolana cement (PPC). Furthermore, SEM-EDS, XRD, XPS, and FTIR were employed to reveal the adsorption mechanism. The results showed that the pseudo-second-order model exhibited higher regression coefficients than the pseudo-first-order model, indicating that chemisorption dominated the adsorption process. The Langmuir equation fitted the P adsorption data well, with maximum P adsorption capacities of 245.8, 226.1, and 210.0 mg g-1 for OPC, PSC, and PPC at 25 °C, respectively. P adsorption capacities decreased gradually with increasing initial pH and reached their maximum values at pH 3. The anions of F-, CO32-, and SO42- negatively affected P adsorption due to the competitive adsorption with Ca2+. The results of XPS, XRD, and FTIR confirmed that Ca-P precipitates (i.e., hydroxyapatite) were the main removal mechanism. A real domestic sewage experiment showed that 0.6 g L-1 OPC effectively reduced the P concentration from 2.4 to below 0.2 mg L-1, with a dosage cost of 0.034 $ per ton. This study indicated that cement, as a low-cost and efficient P adsorbent, has great potential for application in removing P from acidic and neutral wastewater.

Effect of superplasticizer on the fresh and hardened properties of mortars prepared with different types of cement produced from the same clinker

Effect of superplasticizer on the fresh and hardened properties of mortars prepared with different types of cement produced from the same clinker

Application of the Min-Max Stock Method in the Inventory Control of the Raw Materials for the Cement Production at PT XYZ

PT XYZ is the largest cement manufacturer in Indonesia that produces cement with different types of cement, namely OPC, PCC, and PPC. The implementation of its production process, starts with the mixing of raw materials, processing, and packaging to the finished product, namely cement. PT XYZ has a problem in the form of raw material inventory that has not been well controlled because the raw materials are often placed outside the storage area provided by the company due to overloading, thus taking up space that should not be used as a raw material storage area. In this study, the minimum-maximum method is applied to 4 types of raw materials, silica sand, gypsum, trass, and fly ash. By determining the amount of safety stock, minimum stock, maximum stock, reorder point and order quantity, companies can effectively determine the raw material inventory policy to avoid overstock or stockout. The study uses a 99% service level with a 1% risk of out-of-stock products. The results of the study obtained the safety stock value of silica sand 3,854 tons; gypsum 4,405 tons; trass 10,456 tons; and Fly Ash 511 tons. Then, the minimum inventory calculation is carried out, it is known that the minimum inventory results are in Fly ash raw material of 776 tons while the results for maximum inventory are in Trass of 34,613 tons. After the min-max calculation, the ordering policy for each material can be obtained, silica sand 5,255 tons, gypsum 9,111 tons, trass 22,534 tons, fly ash 776 tons.

Determination of the retentive ability of different luting agents in titanium abutments on implant-supported crowns

Implant-supported crowns are either cement-retained or screw-retained. Recently, function and esthetics have been given major focus as advances in implants have greatly improved the longevity of implant restoration. Superior esthetics is seen with cement-retained restoration and is more preferred. However, it is a controversial topic to select the ideal cement type for luting the implant-supported crown. The present study aimed to assess the retentive ability of different luting agents in titanium abutments on implant-supported crowns. The study assessed 60 samples divided into 3 groups of 20 subjects each where luting was done with three different types of cement, namely glass ionomer cement, zinc polycarboxylate, and zinc phosphate, respectively. A testing machine was used to assess the retentive strength of the three types of cement. The study results conclude that the highest retentive strength is seen with zinc polycarboxylate cement, followed by the glass ionomer and zinc phosphate cement.

Comparative study of the bond strength of ZirCAD Multi and ZirCAD Prime ceramics with different types of cements

Zirconia ceramic is a modern material used for different types of prosthetic constructions, characterized by high mechanical resistance and aesthetics. The main difficulties in treatment are related to ensuring a stable and durable bond between the ceramic and dentin. This study examined the bonding strength of ZirCAD Multi (3rd generation) and ZirCAD Prime (5th generation) ceramics when using different types of cements before and after sandblasting the surface of zirconia with Al2O3. For this purpose, an experimental setup was created by 3D printing, in which sintered ceramic cylinders were cemented to dentin slices of natural teeth with different types of cements. From the formed ceramic-dentin constructions, test specimens were cut with a microtome and tested for tensile strength. The results showed an increase in the strength of the bond after sandblasting from 1.1 MPa to 2.4 MPa for ZirCAD Multi and from 1.6 MPa to 3.3 MPa for ZirCAD Prime. Zirconia ceramic ZirCAD Prime (5th generation) showed higher adhesion resistance, with the strongest bond being with the Speed Cem Plus and Panavia V5 cements. With ZirCAD Multi, the maximum tensile strength was achieved with the Rely X Luting Plus and Speed Cem Plus cements. Optimal strength and bond resistance were registered between the new fifth-generation zirconia ceramic and composite cements with MDP (10-methacryloyloxydecyl dihydrogen phosphate) primers.

Finite element analysis of biomechanical effects of mineralized collagen modified bone cement on adjacent vertebral body after vertebroplasty.

Objective: To investigate whether mineralized collagen modified polymethyl methacrylate (MC-PMMA) bone cement impacts the implanted vertebral body and adjacent segments and the feasibility of biomechanical properties compared with common bone cement in the treatment of osteoporotic vertebral compression fractures (OVCF). Methods: A healthy volunteer was selected to perform a three-dimensional reconstruction of the T11-L1 vertebral body to establish the corresponding finite element model of the spine, and the changes in the stress distribution of different types of cement were biomechanically analyzed in groups by applying quantitative loads. Results: The stress distribution of the T11-L1 vertebral body was similar between the two bone types of cement under various stress conditions. Conclusion: Mineralized collagen modified bone cement had the advantages of promoting bone regeneration, good biocompatibility, good transformability, and coupling, and had support strength not inferior to common PMMA bone cement, indicating it has good development prospects and potential.

Research on the Effect of Two Different Polycarboxylic Acid Water-reducing agent on the Sensitivity of Concrete

Polycarboxylic acid water-reducing agent (PCE) is mixed into concrete under different conditions, which brings sensitivity to concrete. This paper establishes a series of evaluation methods by investigating the sensitivity under different conditions. This paper compares the sensitivity of two different PCEs in different parameters of concrete and tests the difference in concrete expansion or slump value under the conditions of different dosages, water consumption, temperature and types of raw materials. The results show that the sensitivity of PC-1 and KZJ-1 is different for different types of cement, and the sensitivity of water consumption, temperature, and raw materials is better than PC-1.