Different Types Of Cement Research Articles

Effect of amine and glycol-based grinding aids utilization rate on grinding efficiency and rheological properties of cementitious systems

In this study, it is aimed to give a new viewpoint of choosing utilization rates and type of grinding aids (GA), taking into account cement-polycathoxylate ether-based water-reducing admixture (PCE) compatibility. For this purpose, the effects of amine and glycol-based GA utilization rate on clinker grinding efficiency and the physical properties of cement were investigated. The setting time, fresh state, rheological properties, and compressive strength of the mixtures prepared with the produced cements were examined. In addition to the control cement containing no GA, two series of cement were produced by the addition of amine- and glycol-based GA to the clinker in four different contents. GA were added to the clinker at the rate of 0.025-0.050-0.075–0.1% of the total clinker and gypsum weight. Triisopropanolamine (TIPA) and Diethanol Isopropanolamine (DEIPA) were used as amine-based and Diethylene Glycol (DEG) and Ethylene Glycol (EG) as glycol-based. Thus, a total of 17 different types of cement having similar Blaine fineness were produced. According to the results, the GA utilization caused the production of cement with narrower particle size distribution. Besides, the GA utilization contributed significantly in terms of grinding efficiency and 28-day strength, and this positive effect increased gradually until a certain GA dosage. It was remarked that the TIPA showed high performance in terms of grinding efficiency and compressive strength, however, the reverse of this behavior was observed in the fresh state rheological properties. In terms of rheological properties, glycol-based GA performed better than amine-based. Irrespective of the GA type, 0.025% and 0.05% were obtained the optimum GA utilization rate in terms of cement-PCE compatibility and compressive strength, respectively.

Impact of cement type and abutment height on pull-off force of zirconia reinforced lithium silicate crowns on titanium implant stock abutments: an in vitro study

BackgroundPull-off forces of cement-retained zirconia reinforced lithium silicate (ZLS) in implant-supported single crowns on stock titanium abutments with respect to abutment height and implant cement were evaluated and compared.MethodsPull-off force of ZLS crowns on stock titanium abutments was evaluated concerning dental cement and abutment height. A total sample size of 64 stock abutments with heights of 3 mm (n = 32) and 5 mm (n = 32) was used. The ZLS crowns were cemented with four different types of cement (one temporary, two semi-permanent, and one permanent). After cementation, water storage, and thermocycling each sample was subjected to a pull-off test using a universal testing machine.ResultsThe temporary cement showed the least pull-off force regardless of abutment height (3/5 mm: means 6 N/23 N), followed by the semi-permanent methacrylate-infiltrated zinc oxide cement (28 N/55 N), the semi-permanent methacrylate-based cement (103 N/163 N), and the permanent resin composite cement (238 N/820 N). Results of all types of cement differed statistically significantly from each other (p ≤ .012). The type of implant cement has an impact on the pull-off force of ZLS crowns and titanium abutments.ConclusionsPermanent cements present higher retention than semi-permanent ones, and temporary cements present the lowest values. The abutment height had a subordinate impact.

Analysis of the influence of different types of cement on the resistance to attack by sulfates

The diversity of the types of cement manufactured, driven by the extensive use of additions, has given cementitious composites properties that can directly interfere in the durability and useful life of concrete. Considering the interaction of sulfate ions with cement hydration products, in order to understand it becomes essential for the proper choice of materials in order to protect the structures from this aggressor agent. In order to verify the influence of the choice of cement type on the resistance to attack by sulfates, this article analyzes the compressive strength; sulfate content, electron microscopy and energy dispersive spectroscopy of mortars made with cements CP II-F-32, CP IV-32 and CP V-ARI submitted to calcium, sodium and magnesium sulfate solutions for 4 months. The specimens exposed to calcium and sodium sulfate solutions showed increased compressive strength at early ages due to the formation of ettringite in the pores. On the other hand, CP II-F-32 cement showed the greatest deterioration due to magnesium sulfate attack.

Petrography and diagenetic evolution of the Barail sandstones of Naga Schuppen belt, North East India: implication towards reservoir quality

Rock-thin section, scanning electron microscopy and X-ray diffraction analyses have been employed to describe in detail the mineralogical constituents, diagenetic alterations and their impact on reservoir quality of Oligocene Barail sandstones of Naga Schuppen belt, North East India. The Barail Group comprises of alternate beds of hard and compact sandstones with siltstone, shale, carbonaceous shale, and a few thin intermittent coal seams in the upper part of the rock sequence. Petrographic analysis indicates that quartz (42.02–55.02%) is the most dominant mineral constituent followed by rock fragments (6.85–15.67%) and feldspars (0.00–1.97%) with different types of cement in the studied sandstones. Quartz overgrowth, formation of pseudo matrix, authigenic growth of secondary mine­rals and precipitation of clay within the pore spaces tend to reduce the primary and secondary porosities of the rocks. However, in certain samples, the grain coating restricts or hinders cementation and preserves porosity during deep burial, but decreases permeability at pore throats. Partial dissolution and intragranular fracturing of the framework minerals provide sites for pore growth. Pyrite framboids and iron oxides inhibit quartz cementation, but infill pore spaces. The present study shows that original pore morphologies, as well as secondary porosities within the sandstones tend to be destroyed to a large extent by the diagenetic processes

Diagenesis and thermal maturity of the Cogollo Group sedimentary rocks in the ANH-CR-Montecarlo-1X well, Cesar-Ranchería Basin, Colombia

The exploration well ANH-CR-Montecarlo-1X, in the southern part of the Cesar-Ranchería basin in Colombia, cuts sedimentary rocks assigned to the Cogollo Group (Barremian-Cenomanian). The present study integrates petrographic techniques (thin section microscopy and scanning electron microscopy), geochemistry (total organic carbon and pyrolysis rock-eval) and basic petrophysics to establish the thermal maturity and potential of these rocks as a conventional or unconventional hydrocarbon reservoir. The results of petrographic analysis revealed that the rocks correspond to quartz sandstones and greywackes and the carbonate rocks to mudstones and wackestones. These were affected by diagenetic processes such as compaction and mineral neoformations. The latter include minerals from the clays group that cover the grains of the rock framework, and other types of precipitates, such as silica, ferrous and non-ferrous carbonate that cement them. Some of these minerals present partial or total dissolution, for which secondary porosity is recognized. Chloritization and illitization of the argillaceous matrix and feldspars alteration to ferrous and non-ferrous carbonate are also observed, which affects the porosity and permeability of the rock. Additionally, during diagenesis micrite is recrystallized to sparite and carbonate precipitation ocurred in the calcareous rocks. The study also shows that the rocks were more affected by compaction than precipitation of the different types of cement, thus reducing their porosity and permeability. Based on these parameters the siliciclastic rocks in study area have a low potential as conventional reservoir but a good potential as non-conventional reservoir (tight sandstones). The geochemical studies in the calcareous rocks exhibit low content of total organic carbon (between 0 and 4.5% with an average of 0.71%), with kerogens type III and IV. They have high levels of organic matter conversion, indicative that the rocks did generate hydrocarbons, but currently are depleted and in a mature state, compatible with a low potential of hydrocarbon generation.

English

BACKGROUND The purpose of this in-vitro study was to compare the colour stability and bond strength of zirconia-based ceramic restorations after hydrothermal aging using conventional layering, heat-pressing, and multilayer veneering techniques. METHODS One hundred twenty specimens’ core (15 x 10 x 0.7) was fabricated from A2-shade zirconia CAD-CAM blocks (IPS e.max ZirCAD). Specimens were divided into 4 groups for veneering (N = 30): [(layering group (L), IPS e.max ceram), (heat – pressing group (P), IPS press), and multilayer group, IPS e max Cad for 2 different types of cement (cemented with RelyX U200 (M1) and PANAVIA SA (M2))]. Aging was performed for (5 - 55°C, 5000). Colour coordinates before and after aging were measured to calculate colour differences (ΔE00). The shear bond strength test was performed with a universal test unit. The data were analysed using the analysis of variance (ANOVA) and Tukey’s Honest Significant Difference test (alpha = 0.05). RESULTS Significant differences were found between the groups in bond strength (P < 0.001). Group M1 had the highest bond strength while Group L had the lowest bond strength. In terms of ΔE00 values, there were significant variations between the groups (P < 0.001). Group M1 had the highest colour stability, while Group M2 had the lowest colour stability. CONCLUSIONS The method of fabrication had an impact on the power of the bond between veneering ceramic and zirconia, as well as its colour stability. The restoration fabricated by a multilayer technique was cemented by resin cement (Rely X U200 Automix) which was found to be more resistant and colour stable. KEY WORDS Veneers, Heat-Press Technique, Bond Strength, Colour Different, Hydrothermal Aging.

Behavior of mortars with different types of cement when induced to Delayed Ettringite Formation (DEF)

The purpose of this paper is to present an evaluation of different types of cement and the incidence of Delayed Ettringite Formation (DEF) through mortar composites cast in the laboratory and exposed to a high curing temperature over a 12-month study period. DEF represents one of the types of Internal Sulfate Attacks (ISA) related to an expansive chemical reaction that occurs inside of concrete involving the sulfates from cement. Experiments involved the assessment of expansions, compressive and tensile strengths as well as microstructural characteristics over time. It was observed that tests performed on mortars and with a specific mix required an extended evaluation period to distinguish the behaviors. Furthermore, high early-strength cement featured the worst binder when faced with DEF.

Sealing Ability of New Translucent Zirconia Crowns Made with Digital Workflow and Cemented with Different Types of Cement.

This article evaluated the sealing capacity of single crowns made of a new zirconia (Katana STML, Kuraray Noritake) when cemented with two different cement types and two different marginal preparation types. Forty intact human anterior teeth, extracted for periodontal reasons, were used. Each sample was prepared with two margin preparations: knife-edge (KE) on one half of the tooth and chamfer (CH) on the other half. Based on the type of cement used, abutments were randomly distributed into one of two groups: Group 1 used resin cement (Panavia V5, Kuraray Noritake), and Group 2 used reinforced glass-ionomer cement (FujiCEM 2, GC). A digital workflow was utilized for crown fabrication. After the cementing procedures, samples were processed, and microleakage and scanning electron microscopic observations were made. Microleakage varied significantly depending on the type of cement combination used. Group 1 samples showed less microleakage (medians: 0.76 for CH and 0.51 for KE in Group 1, and 4.1 and 3.45 for Group 2, respectively) than Group 2 specimens; the difference was statistically significant (P < .000). KE preparation showed less microleakage than CH, although no statistically significant differences were found (P < .0558). Under microscopic observations, some samples showed internal fractures within the zirconia material. KE and CH seal the margin of zirconia crowns similarly. The resin cement system ensured better adhesion than reinforced glass-ionomer cement.

Relationship of Different Properties from Non-Destructive Testing of Heavy Concrete from Magnetite and Serpentinite.

Radiation-shielding concrete has been analyzed by several methods of destructive and non-destructive testing (NDT). Concretes made of crushed basalt, magnetite, serpentinite, and two different types of cement (Portland cement CEM I and slag cement CEM III/A) were studied. In this study, we analyzed concrete columns with a height of 1200 mm and a cross-section of 200 × 200 mm2. The top and bottom of the column were analyzed using data from compressive strength, dynamic modulus of elasticity, water penetration, and diffusion coefficients derived from the electrical resistivity test. This article presents the properties of fresh concrete and concrete after two years of setting. It was determined how the different ratios of basalt, magnetite, and serpentinite affect the individual measured parameters. Furthermore, correlation relations between individual resulting values were analyzed. It was observed that compressive strength generally does not correlate with other results. The diffusion coefficient correlated well with density and water penetration. Little or no correlation was observed in the diffusion coefficient with compressive strength and modulus of elasticity. The results of the study make it possible to refine the testing of heavy concretes in terms of electrical resistivity, and point to the possible use of NDT methods. The results also show which composition of heavy concrete is better in terms of effective diffusivity.

Investigating the compatibility of nickel coated carbon nanotubes and cementitious composites through experimental evidence and theoretical calculations

Nickel coated multi-walled carbon nanotubes (NiMCNTs) are favorable reinforcing nanofillers for modifying cementitious composites due to their preeminent mechanical properties, electrical conductivity, thermal properties and dispersibility. This paper investigates the mechanical properties and compatibility of NiMCNTs filled cementitious composites, having two different types of cement, two water to cement ratios, and two dosages of five types of NiMCNTs. The results show that 0.06 vol% NiMCNTs with small aspect ratios can significantly enhance the mechanical properties of cementitious composites, while NiMCNTs with large aspect ratios play a better strengthening effect at 0.03 vol%. The flexural strength/toughness of cementitious composites containing 0.06 vol% NiMCNTs with an aspect ratio of 200 can be increased by 19.65%/116.78%. Adding 0.03 vol% NiMCNTs with an aspect ratio of 1000 enhances the compressive strength/toughness of composites by 18.61%/47.44%. Besides, NiMCNTs have preferable compatibility to cementitious composites prepared by P·O 42.5R cement with a water to cement ratio of 0.3. The enhancement mechanism is related to the denser microstructure and effective suppression of microcracks in the cementitious matrix by NiMCNTs with filling, bridging and pull-out effects, as well as the high interface bond strength between NiMCNTs and matrix. A strength prediction model for NiMCNTs reinforced cementitious composites is also established to estimate the mechanical strength of cementitious composites containing NiMCNTs with different aspect ratios/contents, showing a small relative error within ±6%/±13% for predicted flexural/compressive strength values in comparison with the experimental results.

Cement hydration kinetics study in the temperature range from 15 °C to 95 °C

The heat evolution during the hydration of cement was examined by multiple calorimetric methods: isothermal, oscillating isothermal, as well as temperature scanning tests in the temperature range from 15 °C to 95 °C. The apparent activation energy (Ea) of several different types of cements were all found to decrease significantly with temperature. Type of additives and water to cement ratio had little influence on the temperature dependence of Ea. The correlation between Ea and temperature may be mathematically simplified to a step function, where Ea is a nonzero constant below a critical temperature (Tcr) and reduces to zero above that temperature. The proposed model of Ea was combined with a scale factor model to simulate the influence of curing temperature on the hydration kinetics of cement with significantly improved accuracy compared to an earlier model.

Description of the concrete carbonation process with adjusted depth-resolved thermogravimetric analysis

AbstractThe thermal gravimetric analysis (TG) is a common method for the examination of the carbonation progress of cement-based materials. Unfortunately, the thermal properties of some components complicate the evaluation of TG results. Various hydrate phases, such as ettringite (AFt), C–S–H and AFm, decompose almost simultaneously in the temperature range up to 200 °C. Additionally, physically bound water is released in the same temperature range. In the temperature range between 450 °C and 600 °C, the decomposition of calcium hydroxide and amorphous or weakly bound carbonates takes place simultaneously. Carbonates, like calcite, from limestone powder or other additives may be already contained in the noncarbonated sample material. For this research, an attempt was made to minimise the influence of these effects. Therefore, differential curves from DTG results of noncarbonated areas and areas with various states of carbonation of the same sample material were calculated and evaluated. Concretes based on three different types of cement were produced and stored under accelerated carbonation conditions (1% CO2 in air). The required sample material was obtained by cutting slices from various depths of previously CO2-treated specimen and subsequent grinding. During the sample preparation, a special attention was paid that no additional carbonation processes took place. As reference method for the determination of the carbonation depth, the sprayed application of phenolphthalein solution was carried out. Microscopic analysis was examined to confirm the assumptions made previously. Furthermore, the observed effect of encapsulation of calcium hydroxide by carbonates caused by the accelerated carbonation conditions was examined more closely.

Carbonation Resistance Classes of Concretes

Abstract Concrete carbonation is a phenomenon that occurs by the penetration into the cement stone of CO2 present in the atmosphere. The phenomenon occurs in the presence of water in which CO2 dissolves, forming carbonate ions, which in turn react with calcium ions in the pores of the concrete, resulting in calcium carbonate (calcite). The diffusion of CO2 occurs through pores and surface defects, it thus penetrates deeper into the concrete and the carbonation reaction can occur at a greater depth, eventually exceeding the thickness of the cover, causing corrosion of the reinforcement. [1] In the case of reinforced concrete bridges, corrosion induced by carbonation of concrete is one of the main causes of degradation. Thus, in the design stage of the reinforced concrete bridge structures, the inevitable process of carbonation of the concrete must be taken into account, in the design of the durability, by calculating the thickness of the concrete cover layer. This article aims to present the concept of carbonation resistance class, which will be a major change in the standard based on which the thickness of the concrete cover for reinforcement will be determined. This presentation is made in the context of the European performance approach to durability. In this sense, an analysis of the experimental results obtained in research on concrete prepared with different types of cements, carried out in collaboration with the laboratory of the Reinforced Concrete Structures Department, within the Technical University of Civil Engineering Bucharest. Proposals for classification in the carbonation resistance classes for concretes prepared with two types of cements are also presented.

Investigation of Fracture Resistance of Zirconia Restorations After Different Surface Treatments

Objective: The purpose of this study was to investigate the effects of the different surface treatments on fracture strength of the zirconia-based ceramic restorations. Methods: Each of 120 dental implant abutments and analogs were used in the present study. Zirconia core materials were manufactured on dental implants by using CAD/CAM device and they were randomly divided into 6 groups (n=20) according to surface pretreatments; control group (Group C), airborne-particle abrasion (Group AA), silica-coating (Group SC), Nd:YAG laser (Group N), bur-cut from cervical region (Group BC), and bur-cut on the functional tubercule (Group BT). Cementation was succeeded with two different types of cements including a dual-cure resin-cement and a glass ionomer cement. The obtained data were evaluated statistically using one-way ANOVA and Tukey tests (p=0.05). Results: No statistically significant difference was found between the groups (p&amp;gt;0.05). Similarly, no statistically significant difference was found between the resin cement and glass ionomer groups with respect to fracture strength values (p&amp;gt;0.05). Conclusion: Within the limitations of the present study, surface treatments and cement have no effect on the flexural strength of zirconia ceramic crowns.

Evaluation of the marginal microleakage of CAD-CAM compared with conventional interim crowns luted with different types of cement: An in-vitro study.

Temporary stage in crowns and bridgework plays an important role in the success and failure of the final restorations. Lack of marginal seal of the temporary restorations can lead to further complications. Recently, digital dentistry has been improved in terms of marginal integrity. The aim of this study was to evaluate and compare the marginal leakage between CAD/CAM and conventionally made Polymethyl methacrylate (PMMA) interim crowns cemented with different temporary luting cements. Sixty resin dies of a maxillary right first premolar were prepared according to the protocol of the tooth preparation for all-ceramic crown. Interim crowns were then fabricated and assigned to two main groups according to the fabrication technique (CAD/CAM technique and conventional technique). Furthermore, the samples were sub-grouped (n = 10) according to the type of the luting cements: Zinc oxide eugenol (RelyX temp E), Zinc oxide non-eugenol (RelyX temp NE), and Zinc polycarboxylate cement (pentron). The specimens were then subjected to thermocycling at 5°C and 55°CC for 30 sec and transfer time of 15 seconds for 1500 cycles. After that, the specimens were immersed in a 2% methylene blue solution for 24 hours. The cemented specimens were sectioned buccolingually and the amount of marginal leakage was evaluated under digital microscope at magnification 50x. The scores of dye penetration were recorded and analyzed using one-way ANOVA at P < 0.05 for all tests. For the fabrication technique, CAD/CAM-made interim crowns had significantly better performance in terms of lower microleakage in comparison to conventionally built interim crowns (P < 0.001). Overall, Zinc Oxide non-eugenol also showed significantly least microleakage as a luting cement then Zinc Oxide Eugenol and the most microleakage was found with Zinc Polycarboxylate regardless of the fabrication method. Interim crowns fabricated by CAD-CAM system are better suited for temporization. Zinc-oxide non-eugenol cements showed the least amount of microleakage in both types of crown.

Emergence of nano silica for oil and gas well cementing: application, challenges, and future scope.

Nanotechnology has opened up a plethora of opportunities and has acquired extreme importance in a myriad of fields to produce enhanced materials. Their special properties make them sustainable for industrial purposes. One of the most crucial processes in the petroleum and geothermal industries is cementing. Various classes of Portland cement are used according to API classifications. The conventional Portland cement fails to perform its function at high pressure and high temperature (HPHT) conditions. Hence, various admixtures are used to improve its properties. HPHT conditions not only have a bad impact on Portland cement by affecting its rheological properties but also reduce its strength, porosity, and permeability. So, additives like nano silica are used to improve its properties. Better compressive strength, low porosity and permeability, higher yield stress, and reduced setting time are some of the major properties that improve by the use of nano silica. This paper discusses in detail the different types of cement, cementing processes, failure of Portland cement, and effect of nano silica as an admixture on the compressive strength, rheology, porosity, and permeability of the cement. Furthermore, the upcoming challenges in cementing are discussed along with future potential in this field.

Machine-driven simulation of removing luting agent remnants from implant surfaces: An investigator-independent assessment of cleaning protocols

IntroductionTo simulate removing luting agent remnants from crowns fixed onto implant-abutment analogs using a standardized machine-driven protocol including a scaler and air polishing or sonic. Material and methodsA motor-driven device was constructed that controlled the rotational speed of the specimens, machining distance, contact pressure, and working time. A standardized layer of cement (Provicol, VOCO; Cuxhaven, G; Ketac Cem, 3MEspe; Seefeld, G; or Rely X Unicem, 3MEspe, Seefeld, G) was placed onto the finishing line of the crowns luted onto titanium-abutment analogs. The cement layer was scaled with a fresh titanium scaler maneuvered by the motor-driven device and treated with air polishing or sonic. Protocol 1: Scaling only for 20s, 40s, or 60s; n=20; protocol 2: 40s of scaling plus 20s of air polishing; protocol 3: 20s of scaling plus 40s of air polishing; protocol 4: 20s of scaling plus 40s of sonic; protocol 5: 40s of scaling plus 20s of sonic; protocols 2–5: n=10. Cement remnants were counted digitally as “percentage of remnants”. Statistics: mean, standard deviation, Bonferroni post hoc tests; α=0.05. ResultsKetac Cem was easily removed by scaling only and Provicol by scaling and air polishing, but the self-adhesive resin composite cement Rely X Unicem was not removable with the device. Only remnants of Provicol could be significantly reduced by further treatment after scaling (p<0.001). ConclusionThe presented motor-driven device enables reproducible investigations of various cleaning protocols and is thus useful to create an overview of cleaning protocols needed for the different types of cement.

Curing conditions impact on compressive strength development in cement stabilized compacted earth

Cement is a common candidate for soil treatment when stabilization is required. Its employment in compacted earth blocks requests curing the product as efficiently as possible to obtain satisfactory performances. In this context, many practitioners’ recommendations exist. However, no studies have stated clearly optimum curing method required to achieve best possible strength for cement stabilized compacted earth. In this study, an exploratory analysis was used to assess the influence of moist curing duration on strength development in cement stabilized compacted earth. For this investigation, two natural earths stabilized with different types of cement were considered. The main differences between the chosen cements are their clinker content and strength class. The applied moist curing method consists of conditioning samples in moist environment (99.8% ± 0.2%RH) at ambient temperature (21 °C). Curing duration was varied between 0 (no curing) and 21 days. The uniaxial compressive strength was used as a practical indicator to inspect strength development in dry and wet conditions. Results demonstrate that moist curing is profitable until 7 days regardless of the formulation. In addition, results show that efficiency of cement stabilization depends on earth characteristics rather than cement composition. To discuss moist curing in more detail, accelerated curing conditions performed at 60 °C in ambient and moist environment were analyzed. In conclusion, some recommendations on the optimization of cement usage in compacted earth were provided.

Calcium hydroxide influence in autogenous self-healing of cement-based materials in various environmental conditions

Abstract Several factors, such as chemical shrinkage or environmental attack can produce concrete cracks. Calcium hydroxide content from the environment or cement hydration can promote the self-healing phenomenon (SHP). This study evaluates the calcium hydroxide concentration influence on the self-healing phenomenon of cement-based materials. Cracked mortars with different types of cement, such as a filler, pozzolanic, and high initial strength, were exposed to four environmental conditions. Titration was the method proposed to determine the amount of calcium hydroxide content leached in the water, and the cracks closure were analyzed by optical microscopy. CPII F (Portland Cement, type II, compound with limestone) samples showed no trend to Ca(OH)2 leached, and to superficial cracking closure. Regarding CPV (Portland cement, type V, high initial strength cement) samples, their behavior showed the highest Ca(OH)2 content to all environmental exposure, and cracking closure to samples in submerged condition. Thus, a significant influence in the cracks´ closure regarding the presence of Ca2+ leached to the exposure environments, and a water source related to this behavior seems to be a primary factor to improve the SHP.

Exploring the Effects of Pozzolans on Different types of Portland Cements in Sustainable Cement-Based Applications

The sources of pozzolans could be natural, industrial and agricultural wastes that are recycled into concrete and mortar applications. There have also been many studies and recommendations guiding the use of blending these pozzolans from multiple sources with cement with the aim of producing more durable, greener and sustainable mortar/concrete. These investigations are mostly based on testing these pozzolans with a certain type of cement and making recommendations on the optimum percentage replacements. This type of study underscores that a pozzolan can behave differently with other types of Portland cements with varying distinct chemical compositions that associate the cement with its type. This could result to a particular pozzolan having different optimum percentage cement replacements with different types of cement and hence results in less durable concrete of which this study intends to address. The pozzolan used in this study is Pulverized Calcined Clay (PCC) and the types of cement is based on the British and American standards classification. The cement variants used in this study is broadly rapid hardening and low heat cement form the two (2) major cement brands in Nigeria. The X-Ray Fluorescence (XRF) analysis was performed on the cements and the PCC to determine their oxide compositions and classify the pozzolan, the Strength activity index (SAI) of the pozzolan was also determined. The optimum percentage replacements (replacement level with maximum strength) of the cements with the pozzolan was also determined. The results indicate that the optimum replacements for the low-heat cement was at 20% replacement with PCC and substantially higher for the rapid-hardening cement. This could be adduced to the difference in the chemical compositions as shown in the XRF analysis. It was concluded that the optimum replacement of different cement types with a pozzolan could vary, resulting to less durable concrete when a single optimum replacement is recommended across all cement types. It is therefore recommended that the optimum replacements of cements with pozzolans should be specific to a cement type and recommended that optimum replacement for other cement types with same pozzolan be determined and not generalized across all cements.