Pozzolanic Materials Research Articles

Assessment of perlite by-product as pozzolanic material in cement pastes

This research investigates the suitability of perlite by-product as a potential pozzolanic material in cement-based pastes and compares its performance with natural pozzolan. The study evaluates both the fresh and hardened properties of the pastes. The investigation involves analysis of hydration heat records, hydration formed products, water demand, and setting times, that preseted small deviations. The findings reveal that the perlite by-product exhibits promising characteristics, suggesting its viability as a pozzolanic material in cement pastes. Perlite specimens presented greater mass loss due to calcium-aluminum species, according to TG at early age, as well at later age as depicted in DSC curves. Diffraction patterns and IR assignments showed that waste-perlite systems formed carbonated species with different crystallinity at 180 days. Nevertheless, compressive strength and open porosity of those pastes exhibited behavior similar to the ones incorporating natural pozzolan, apart from 10 % to 20 % systems, where perlite seems to offer slightly greater strength at later age. This study sheds light on the potential benefits of utilizing perlite by-product as an alternative pozzolanic material, rather than depositing it and cause environmetanl problems. Based on its later age properties, perlite could enhance the performance and sustainability of cement-based products in various applications.

Sustainable development of pavement base stabilization using future road base material (FROBM)

Sustainable road construction has emerged as a critical issue in assessing natural resources and urban development. With the rapid expansion of pavement networks to meet growing traffic demands, road base construction relies heavily on the consumption of natural aggregates and Ordinary Portland Cement (OPC) through the cement-treated base (CTB) technique. This practice contributes to the global warming and greenhouse gas (GHG) emissions associated with road construction. This study investigated a novel road base material, Future Road Base Material (FROBM), which emphasizes both eco-friendliness and economic advantages. Fine crushed rock (FCR) served as the parent aggregate and was modified with a chemical binder comprising 4% of the FCR weight. The proposed sustainable cementitious material, functioning as a non-OPC binder, incorporated fly ash and hydrated limestone as pozzolanic materials, along with sodium hydroxide (NaOH) as an alkali additive. An asphalt emulsion (AE) was employed as a special additive to enhance crucial pavement engineering properties. Through life cycle analysis (LCA), the construction activities and material acquisition of each stabilized base technique were evaluated in terms of project costs and carbon footprints. The non-OPC binder offered sufficient compressive strength for a stabilized base course. Furthermore, the addition of AE improved the elastic modulus and modulus of rupture of the non-OPC binder-stabilized mixture. Utilizing a non-OPC binder and AE in the base layer provides advantages in terms of construction cost and environmental impact. Although the costs increased slightly, the GHG emissions were reduced by approximately 30% compared to conventional base materials, with equivalent functionality and service life for road construction. The proposed stabilizing agent reduced the operational processes and demand for natural aggregates compared with the unbound FCR base course. Road-base stabilization using a non-OPC binder and AE represents an innovative approach to mitigate waste in coal mining and power plant industries by transitioning to a cleaner product. The concept of the FROBM serves as a valuable guideline for the development of future sustainable pavement materials.

CARBON FOOTPRINT REDUCTION USING GEOPOLYMER CONCRETE

The size and complex nature of today's construction project resulted in a global increase of the carbon footprint. Increased carbon dioxide emissions results in a severe deterioration to the environment and negative health implications. Recent studies showed that the production of 1 metric ton of portland cement results in the evolution of 0.9 metric tons of carbon dioxide. At this rate, the construction industry represents a significant threat on mankind. This paper presents geopolymer (cement-free) concrete applications in the United States local construction market. Geopolymer concrete production depends on the activation of a pozzolanic supplementary cementitious material (SCM) with a high aluminosilicate content using alkaline solution as sodium hydroxide (NaOH). The SCM activated material-known as precursor-forms a three-dimensional polymer that binds the aggregates instead of hydrated portland cement. The widespread of geopolymer concrete will significantly reduce the need to portland cement; hence, reduces the carbon emissions resulting from cement production. In addition to the environmental advantages, geopolymer concrete is highly durable due to the fine size of SCMs particles. Geopolymer concrete is more resistant to alkali-silica reactivity, and early age cracking. The widespread of geopolymer concrete in construction industry, especially in infrastructure projects, will result in significant improvement in projects condition, and lower the need to frequent maintenance, repair, and replacement of projects.

CARBON FOOTPRINT REDUCTION USING GEOPOLYMER CONCRETE

The size and complex nature of today's construction project resulted in a global increase of the carbon footprint. Increased carbon dioxide emissions results in a severe deterioration to the environment and negative health implications. Recent studies showed that the production of 1 metric ton of portland cement results in the evolution of 0.9 metric tons of carbon dioxide. At this rate, the construction industry represents a significant threat on mankind. This paper presents geopolymer (cement-free) concrete applications in the United States local construction market. Geopolymer concrete production depends on the activation of a pozzolanic supplementary cementitious material (SCM) with a high aluminosilicate content using alkaline solution as sodium hydroxide (NaOH). The SCM activated material-known as precursor-forms a three-dimensional polymer that binds the aggregates instead of hydrated portland cement. The widespread of geopolymer concrete will significantly reduce the need to portland cement; hence, reduces the carbon emissions resulting from cement production. In addition to the environmental advantages, geopolymer concrete is highly durable due to the fine size of SCMs particles. Geopolymer concrete is more resistant to alkali-silica reactivity, and early age cracking. The widespread of geopolymer concrete in construction industry, especially in infrastructure projects, will result in significant improvement in projects condition, and lower the need to frequent maintenance, repair, and replacement of projects.

Mechanical properties of silica fume based concrete: A review

The significant industrial growth accompanying rapid urbanization has spurred a heightened demand for concrete. Cement production, a primary ingredient of concrete, results in substantial carbon dioxide (CO2) emissions. To mitigate this impact, alternative pozzolanic materials like silica fume (SF) can be incorporated. SF, an industrial byproduct, serves as a supplementary cementitious material (SCM), offering benefits of waste recycling. This study aims to comprehensively review the addition of SF as an SCM replacement, with a specific focus on the mechanical properties of concrete. Numerous scientific papers were analyzed and carefully examined from the period of 1998 to 2023, which forms the bibliometric core of this study. The entire scopus database was examined for co-occurrence of keywords and actively contributing countries and results were shown through network diagrams. The effect of SF addition on fresh properties as well as mechanical properties were discussed. The inclusion of SF in range of 10–25% by quantity of cement was found to have increased split tensile strength, compressive strength and flexural strength. However, the addition of SF beyond 25% replacement level can have an adverse impact on the overall characteristics of the composite mix. The present study summarizes the major trends as reported in the available literature where SF has been used as SCM. Apart from finding the general trends, various research gaps have been identified.

Soft Computing Modeling Including Artificial Neural Network, Non-linear, and Linear Regression Models to Predict the Compressive Strength of Sustainable Mortar Modified with Palm Oil Fuel Ash

Producing sustainable concrete and mortar is the idea that have been investigated by many researchers in the world through using waste materials in the mortar or concrete compositions to reduce the thread on the environment. In order to predict the compressive strength of mortar, this article proposes statistical models utilising linear regression (LR), nonlinear regression (NLR), and artificial neural network (ANN) based on experimental data collected from prior research in the field. The pozzolanic material used in mortar is agricultural waste, specifically Palm Oil Fuel Ash (POFA). In order to choose the most efficient model, the proposed models were evaluated using several statistical parameters. When compared to alternative models (Linear regression, nonlinear regression, and ANN), the one developed using ANN proved to be the most efficient in terms of approach, giving lower values for root mean square error (RMSE) and mean absolute error (MAE) which were 5.11, and 4.175 respectively. The suggested ANN model performed well according to the scatter index (SI), and the coefficient of determination value (R2) value was 34% more than the R2 in the LR model and 23% greater in the NLR model.

Enhancing Soil with Low-Cost Pozzolanic Materials: Rice Husk Ash and Groundnut Shell Ash Compared to Cement

Enhancing Soil with Low-Cost Pozzolanic Materials: Rice Husk Ash and Groundnut Shell Ash Compared to Cement

GEOTECHNICAL AND MINERALOGICAL CHARACTERISTICS OF LATERITIC SOIL AND LOCUST BEAN (PARKIA BIGLOBOSA) PODS ASH AS CONSTRUCTION SOIL

African locust bean (Parkia Biglobosa) has been in great demand and consequently yielding large amounts of the pods which could be a potential hazard to the environment. Converting the pods to ash that would be utilized as construction material is another way of handling them properly. The effects of the mineralogy of the soil on its geotechnical characteristics when the soil is treated with locust bean pod ash have been given very little attention. Therefore, this study considered the effects of locust bean pod ash (LBPA) and the mineralogy of lateritic soil on some geotechnical properties necessary for it to be used as subgrade or foundation soil. The determination of the chemical constituents of the LBPA was carried out using Atomic Absorption Spectrometer. The lateritic soil was characterized by identifying the clay minerals as well as non-clay minerals present in the soil using the x-ray diffraction technique and preliminary tests were also carried out to properly rate the soil. The soil was treated by applying dosages of LBPA 0 – 25% at intervals of 5% and the percentages were measured by weight of the dry soil. The tests conducted on the prepared soil samples with LBPA were specific gravity, consistency indices, compaction (British Standard Light), California bearing ratio and direct shear box test. The LBPA was found to be an acceptable pozzolanic material for the treatment of the lateritic soil. The lateritic soil was observed to belong to soil groups A-2-6(0) in the AASHTO and poorly graded sand (SP) in USCS ratings. It was also observed that the non-clay minerals present in the soil were quartz, feldspar and mica whereas the clay minerals present were kaolinite, iolite, vermiculite and chlorite which had a significant influence on the geotechnical characteristics of the soil. The specific gravity of the LBPA was relatively low and the additions of LBPA reduced the specific gravity of the soil. The consistency indices also dropped and subsequently increased with the further addition of LBPA. The increase in LBPA contents caused increments in the optimum moisture content while the maximum dry density and shear strength parameters reduced. The strength characteristics like the California Bearing Ratio of the lateritic soil improved by 173.91% at the addition of 5% LBSA content which was determined to be the optimum dosage.

Supplementary cementitious material based on calcined montmorillonite standards

The most effective approach to mitigating the environmental impact of cement production is through the utilisation of pozzolanic materials to prepare blended cement. Calcined kaolinitic clays are one of the most promising materials to be used as supplementary cementitious materials (SCM) due to their final performances. However, there are locations where kaolinitic rocks are not available. This work presents the study of two dioctahedral smectite standards from the Clay Minerals Society (CMS), SWy-3 and SAu-1, to be used as references. After thermal activation optimisation, their pozzolanic performances are compared with those of low-grade kaolinitic clay. On the one hand, raw SWy-3 has an amorphous content of ∼80 wt%, considered montmorillonite, with quartz and feldspars. The optimum calcination temperature was 800ºC, at which the smectite is fully dehydroxylated (as determined by thermal analysis) but not completely amorphized (as shown by powder diffraction). After calcination (800ºC), with a median particle size by volume (Dv,50) of ∼11 μm, ∼480 J/g were released at 7 days in the R3 test. On the other hand, SAu-1 has a higher amount of amorphous content, ∼96 wt%, which includes interstratified illite/smectite. The optimum calcination temperature was found to be 750ºC. This sample (Dv,50 ∼10 μm) gave 452 J/g at 7 days in the R3 test. The optimised active smectites gave a pozzolanic activity comparable to clay with 30–35 % kaolinite, as determined, for the first time, by the R3 test. This work has established descriptors for the activation of natural smectites/bentonites and reference values for the resulting smectite-based SCMs.

Microscopic analyses and performance characteristics of granite powder blended cement

This research investigates the characteristics of Granite Powder (GrP) and its potential use as a partial replacement for cement in mortar production. The GrP samples were analyzed via microscopic techniques. The effects of GrP Blended Cement (GrPBC) were examined on the workability and mechanical characteristics by partially replacing Ordinary Portland Cement (OPC) with 0–40 wt% GrP in 4 wt% increments. Life cycled assessment in terms of Embodied Energy (EE) and Global Warming Potential (GWP) of GrPBC-based mortar were assessed based on cradle-to-gate boundaries and the sustainability and economic indexes were determined at 28 days compressive strength. The study proposed new models to predict the compressive strength of GrPBC with respect to Water to Binder (W/B) ratio. The presence of active minerals depicts GrP as pozzolanic materials. The optimum replacement level of GrP in the blended mix, based on the fresh and hardened properties of GrPBC, is 20 wt% to achieve 75% of the strength activity index. GWP and EE declined as the GrP in the mixtures rose. The best sustainable and economic prospects were attained at the 25 wt% GrP replacement level. The compressive strength and the W/B ratio are highly correlated. Thus, GrP has proven to be a sustainable construction material in the construction sector.

Statistical assessment of the factors influencing fly ash reactivity

Siliceous fly ash is a pozzolanic supplementary cementitious material often used in cement and concrete production. The influence of the chemical, mineralogical and physical properties of 75 siliceous fly ashes on their reactivity was examined in this study. The reactivity was analyzed by relative mortar compressive strength and a rapid screening test (a version of the R³ test). A statistical data analysis was carried out to evaluate the factors influencing the reactivity of the ash. The screening test was found to be able to predict the reactivity within short periods of time, while the relative strength is not a good measure for reactivity. It was also found that the TiO2 and chloride content of the fly ash can serve as an indicator for its reactivity.

A Comparative Analysis of Compressive and Flexural Strength in Concrete with Partial Cement Replacement using Waste Glass Powder

This experimental inquiry delves into the evaluation of compressive and flexural strengths in concrete through the utilization of waste glass powder as a partial substitute for cement. Compressive strength is a key metric, indicating the concrete’s ability to effectively support structural axial loads, while flexural strength signifies its capacity to withstand deformation under bending, specifically the maximum tensile stress it can endure without fracturing when subjected to a bending moment. Certain pozzolanic materials have demonstrated the ability to enhance the mechanical strength of concrete when used as a cement replacement, and waste glass powder is among them. To address this, the experimental investigation included the substitution of cement with glass powder at different proportions (0%, 10%, 15%, 17.5%, and 20%) in both cubic and prismatic samples. Compressive strength and flexural strength tests were made following the curing of the samples for 7, 14, and 28 days. The findings indicated that the 17.5% cement replacement level exhibited a 6.07% over-strength for compressive strength and a 6.85% over-strength for flexural strength on the 28th day. However, the 15% replacement showed superior strength compared to a 10% replacement, and the 10% replacement was stronger than a 0% cement replacement. Notably, the 20% cement replacement displayed negative over-strength percentages, specifically -2.42% in compressive strength and -1.42% in flexural strength on the 28th day. This deviation raises concerns about its suitability for use in concrete applications, signifying that a 20% replacement may not be recommended.

Strength Characteristics and Rheological Behavior of a High Level of Fly Ash in the Production of Concrete.

This study investigates the valorization of coal fly ash (FA-C) generated by the Jerada thermal power plant, aiming to address the pressing need for sustainable construction practices and reduced greenhouse gas emissions in the concrete industry. It is widely used as a pozzolanic material. The key objective is to harness the potential of FA-C as a supplementary material in concrete production, which not only reduces costs but also contributes to environmental sustainability. To achieve this objective, various concrete mixtures were formulated, with FA-C serving as a partial substitute for cement at percentages ranging from 15 to 50%. According to ASTM standards, compressive strength tests were conducted on standard-sized cylinders at 7 and 28 days. The results revealed that the blend containing 15% FA-C exhibited the highest compressive strength, indicating its effectiveness as a concrete additive. Furthermore, this study delves into the rheological properties of concrete mixes, an essential aspect of successful concrete processing. It was observed that a higher replacement level of FA-C significantly improved the rheology, leading to reduced water demand and a linear decrease in plastic viscosity over time. The rheological parameters stabilized after a certain period, demonstrating the controllability of concrete flow behavior with FA-C. The investigation also employed three analytical methods-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM)-to comprehensively analyze both raw materials and processed samples. FTIR analysis highlighted the minimal impact of FA particles on hydration product formation, emphasizing the role of FA-C in enhancing the concrete's strength. XRD analysis confirmed the presence of an amorphous phase crucial for FA's reactivity. SEM observations revealed that concrete with 15% FA-C exhibited a more uniform microstructure with aluminosilicate gel, while 50% FA-C mixes showed increased porosity and nonhomogeneity due to unreacted FA particles.

Structural characterisation and reactivity measurement of chemically activated kaolinite

This study examines the structural evaluation of differently activated kaolins for potential use as supplementary cementitious materials (SCM) or as precursor for alternative cementitious materials (ACM). Chemical activation involved amorphizing the kaolinite structure using varying phosphoric acid concentrations, reaction times, and temperatures. Metakaolin obtained via thermal activation served as a comparison. Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) characterization of the activating solutions revealed phosphoric acid activation leading to dealumination in kaolinite structures, with temperature emerging as the most significant parameter. X-ray diffraction (XRD) confirmed amorphization, attributed to the dealumination process causing Al loss and creating new Si–O–Si interlayered bonds, as monitored by 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) tracking the change from Q3 to Q4 environments. Furthermore, pozzolanic activity was assessed through Ca(OH)2 consumption and reaction heat release via modified Chapelle and R3 tests, respectively. Kaolinite subjected to intensive chemical activation exhibited high reactivity and increased specific surface area, indicating its potential as a pozzolanic material. Keywords: Kaolin; Chemical activation; Supplementary cementitious materials; Alternative cementitious materials; Dealumination; Pozzolanic reactivity.

Mineralogical Evolution of High-pH/Low-pH Cement Pastes in Contact with Seawater

In facilities for the geological disposal of radioactive waste in coastal areas, the long-term alteration of cementitious materials in engineered barriers is expected to occur due to the ingress of groundwater derived from seawater. Although the reaction between cement and seawater has been studied, the alteration behavior caused by the reaction between seawater and low-pH cement, which is expected to be used in a disposal facility, has not yet been clarified. In this study, the effects of cement type on cement–seawater interactions were investigated, and the chemical stability and mineral evolution of cement pastes caused by reactions with seawater were determined. The dissolution of cement hydrates occurred upon increased contact with seawater, and the formation of secondary minerals, including carbonate and Mg-containing minerals, was observed. The progress of dissolution depended on the mineral composition of the initially formed cement hydrates, and low-pH cement containing pozzolanic materials showed less resistance to seawater. Differences in pH and Si concentration that are due to the type of cement used had a strong influence on the evolution of minerals (especially Mg-containing minerals), implying that the formed mineral species possibly affect the migration characteristics of radionuclide.

An experimental study on the sulfuric acid resistance of mineral additive mortars

Mineral additives are preferred to improve the physical, mechanical and durability properties of cement-based composites and to reduce the use of cement to prevent environmental pollution and high production costs. Within the scope of this study, a new pozzolanic material, ground profillite powder (GPP), was evaluated by comparing it with granular ground blast-furnace slag (GGBFS), and it was used as a substitute for cement at ratios of 5, 10 and 15% by weight. The effects of these two mineral additives on the mechanical and physical properties of mortars and their resistance to sulfuric acid (SA) were investigated. In the production of the mortar samples, CEM I 42.5/R-type Portland cement (ordinary Portland cement) was used as the binder, and 0–4 mm crushed sand was used as the aggregate. Mineral additive and non-additive mortars were produced in the laboratory environment in dimensions of 40 × 40 × 160 mm. Spreading values, bending and compressive strengths, water absorption and porosity values and weight and strength loss values under the effect of SA were examined comparatively. It was determined that the mortar samples produced using GPP showed higher resistance to SA attacks than the pure and GGBFS-added mortars, reducing weight losses up to 21% and compressive strength losses up to 30%.

Experimental Study of Compressive Strength and Flexural Strength of Standard Concrete by using Metakaolin as Mineral Admixture

This experimental study investigates the influence of metakaolin as a mineral admixture on the compressive strength and flexural strength of standard concrete (M-25). Metakaolin, a highly reactive pozzolanic material, was introduced as a partial replacement for cement by weight. Metakaolin is a valuable addition to many concrete mixes. It can improve the strength, durability, and resistance of concrete, making it a more versatile and sustainable material. Here are some of the key properties of metakaolin: • High pozzolanic activity: Metakaolin is a highly reactive pozzolan, which means that it reacts with calcium hydroxide to form a gel that binds the concrete particles together. This gel helps to improve the strength, durability, and resistance of concrete. • Fine particle size: The particle size of metakaolin is smaller than the particle size of cement, which means that it can fill the voids in the concrete matrix and improve the density of the concrete. • High surface area: The high surface area of metakaolin also contributes to its pozzolanic activity. The larger surface area provides more sites for the reaction between metakaolin and calcium hydroxide to take place. • Low water content: Metakaolin has a low water content, which means that it does not contribute to the water-to-cement ratio of the concrete. This helps to improve the strength and durability of the concrete. • Chemical resistance: Metakaolin is resistant to a variety of chemicals, including acids, alkalis, and salts. This makes it a good choice for use in concrete that will be exposed to harsh environments. • Heat resistance: Metakaolin is also resistant to high temperatures. This makes it a good choice for use in refractory materials and other high-temperature applications. The research aimed to assess the impact of metakaolin on the mechanical properties of concrete, with a focus on its ability to enhance compressive The research aimed to assess the impact of metakaolin on the mechanical properties of concrete, with a focus on its ability to enhance compressive strength and flexural strength. The study involved the preparation of M-25 grade of concrete mixes with PPC 33 grade cement, locally available sand and aggregate with varying metakaolin proportions, ranging 10%, 20% and 30% by weight of cement. Specimens were cast and cured under controlled laboratory conditions. Compressive strength tests were conducted on cubical specimens, and test after 7 and 28 days and flexural strength tests were conducted on beam specimens, and test after 28 days respectively. Results revealed that the inclusion of 10% and 20% of metakaolin led to improves the 28 days compressive strength and flexural strength by 3.33% and 5.34% as compared to normal concrete respectively. The increase in strength is attributed to the pozzolanic reaction between metakaolin and calcium hydroxide, resulting in improved microstructure and reduced pore size within the concrete matrix.

Effects of raw and different calcined bentonite on durability and mechanical properties of cement composite material

Bentonite is a natural pozzolanic material mostly composed of SiO2 and employed in cementing materials for the reduction of cement consumption and CO2 emission besides improving performance of cement composite material by consuming portlandite to form extra C-S-H gel. So, many researchers studied on partial replacement of bentonite to improve concrete performance. However, bentonite mostly exists as a consolidated form that needs treatment for activation of pozzolanic reactivity to improve performance of cement composite materials. However, it is not well known how different replacement of raw and calcined bentonite affects performance of cementing materials in different hazardous environment. Hence, the present study identified the most influential replacement of bentonite, evaluating different calcined and raw bentonite in environments of acids, salt, and elevated temperature in addition to assessing the mechanical and physical properties of cement composite material. So, the results indicate that the employment of raw and calcined bentonite reduces the fresh bulk density, improves compressive strength, and Vicker hardness at 28 days, reduces the mass loss due to 56 days immersion in 5% HCl, 10% NaCl, and 5% HNO3 compared to the control mixture. Moreover, the employment of calcined bentonite at 800 °C significantly improved the durability and mechanical properties of cement composite materials compared to the control mixture. Specifically, replacing bentonite calcined at 800 °C for 3hs by 20% has the highest compressive strength than all samples after 28 and 56 days. Besides these, the study reveals that the corrosion potential of steel bars embedded in the mortar is reduced as the proportion of raw and different calcined bentonite increases. Generally, the employment of calcined bentonite is very beneficial to get improved performance on mechanical and durability properties of cement composite materials.

Experimental Study of the Moisture Resistance of Cement Mortar Using Pozzolan Materials and Calcium Stearate.

Nanosilica and diatomite are pozzolanic resources rich in SiO2. In this study, the purpose of this study was to improve the moisture resistance of the specimen by producing a mixed material using pozzolanic materials and calcium stearate and adding it to cement mortar while stirring. The results showed that the hydration reaction was not activated when calcium stearate adhered to the fine particles of nanosilica; it existed simply in the form of a filler inside the specimen. Diatomite, due to its atypical particles and porosity, may have greater water tightness than nanosilica because of the pozzolanic reaction in particles to which calcium stearate is not attached.

Experimental Study On Strength of Concrete Using Nano silica

The test on hardened concrete were destructive test on cube for size (150×150×150 mm) at 7, 14, 28 days of curing as per IS: 516-1959, flexural strength test on beam (100×100×500 mm) at 7, 14, 28 days of curing as per IS: 516-1959 and split tensile strength test on cylinder (100mmφ×200mm) at7, 14, 28 days of curing as per IS: 5816-1999. The primary aim of this study is to assess the effectiveness of silica fume as a pozzolanic material for replacing cement in concrete. It is anticipated that incorporating silica fume into concrete will enhance its strength properties. In this study, the combination of 5% nanosilica and 10%metakaolin which replaced part of the cement had the best results in the Mechanical properties of concrete with a 15% increase in the compressive strength and a 40%increase in the flexural and tensile strength of concrete.