Use Of Silica Fume Research Articles

An Experimental Study on Self Compacting Concrete with Partial Replacement of Cement by Silica Fume and Crumb Rubber

Abstract: Self-compacting concrete (SCC) is a type of concrete that can flow and consolidate under its own weight without the need for vibration. SCC has many advantages such as improved workability, durability, surface quality, and reduced noise and labour. However, SCC also requires a high amount of cement and fine materials, which increases the cost and environmental impact of concrete production. Therefore, the use of supplementary cementitious materials such as silica fume and crumb rubber is beneficial to reduce the cement content and enhance the properties of SCC. This study aims to explore the effects of mixing silica fume and crumb rubber on the fresh and hardened properties of SCC. This involves the preparation of various concrete mixes with different percentages of cement replaced by silica fume and crumb rubber. Through a series of experiments, we evaluate the fresh and hardened properties of the SCC mixes, fresh properties such as workability, passing ability, and filling ability, while hardened properties including compressive strength, tensile strength, and flexural strength. The result obtained from these tests are compared with conventional concrete of M30 grade od concrete specimens. Hence the use of silica fume and crumb rubber leads to reduction in cement quantity for construction purpose and its use should be promoted for better performance as well as environmental sustainability.

Rheology of Superabsorbent Polymer-Modified and Basalt Fiber-Reinforced Cement Paste with Silica Fume: Response Surface Methodology

A composite's rheology can be changed by adding superabsorbent polymer (SAP) and basalt fibers and using silica fume. This study aimed to investigate the effects of these components on the viscosity and shear stress parameters of the paste. The proportions of the components were varied, with SAP content ranging from 0.01% to 0.03%, basalt fiber from 0% to 0.50%, silica fume (micro silica) at 15%, and water content from 0.40 to 0.50. Response surface methodology was used to optimize the mixture proportions, and the rheological properties of the resulting pastes were characterized using a rheometer. Results showed that the addition of SAP and basalt fiber had a significant impact on the rheological properties of the paste, with increasing amounts of both resulting in increased viscosity and shear stress. Overall, this study highlights the potential of SAP and basalt fiber in advances of the rheology of cement paste and provides insight into the optimal proportions of these components for achieving desired rheological properties. The findings of this study could be useful in developing high-performance concrete with enhanced rheological properties, which could have a wide range of applications in the construction industry. In addition, 0.50% BF, 0.01% SAP, and 0.445 water-to-cement were found as optimum proportions regarding the rheology of the cement paste.

Effect of silica fume on fracture analysis, durability performance and embodied carbon of fiber-reinforced self-healed concrete

Nowadays concrete industry is trying to develop sustainable and energy efficient materials. One of the techniques is to develop crack free concrete. Therefore, this study focusses on the use of different supplementary materials like silica fume as substitute of cement to characterize the self-healing capacity of fiber-reinforced concrete in order to produce crack free concrete. The employed concrete consists of cement Type-I, synthetic fibers of polyvinyl alcohol (PVA) type with 0.5 % by the total volume of the mix, and two different types of self-healing materials. Cement was replaced by silica fume (SF) up to 15 % with an increment of 2.5 %, sand passing from sieve # 16 and CA of size 12 mm was used to produce high-strength concrete. Three-point bending test and microscopic examination were used to investigate the role of fibers on the self-healing efficiency of fiber-reinforced concrete specimens. Specimens were pre-cracked in the range of 50–100 μm at 14 days of curing and then, placed in water for 14, 56-days water condition to assess the effect of self-healing. Digital high-range microscope was used to measure crack width after pre-cracking and at the end of every exposure duration. After the specified exposure duration, specimens were microscopically observed again to check the crack healing and re-loaded up to final failure. Outcomes were taken in terms of peak load increase value after healing stage (FCPL), controlling crack propagation due to healing effect termed as (IFTR), effect of cracking on fracture energy in terms of (IFER) and Embodied Carbon and Embodied Energy. It was found from test results that the healing efficiency in terms of FCPL, IFTR, and IFER was improved, due to the use of silica fume as it has lower surface area then OPC, which triggers healing rate faster by accumulation of healed produces near crack surface in early age. Furthermore, durability performance in terms of embodied carbon and embodied energy is also reduced because of full-crack healing, which shows profound healing effect.

Effect of Silica Fume Utilization on Structural Build-Up, Mechanical and Dimensional Stability Performance of Fiber-Reinforced 3D Printable Concrete.

It is known that 3D printable concrete mixtures can be costly because they contain high dosages of binder and that the drying-shrinkage performance may be adversely affected. Mineral additives and fibers are generally used to control these negative aspects. In this study, the use of silica fume, a natural viscosity modifying admixture, was investigated to improve the rheological and thixotropic behavior of 3D printable concrete mixtures reinforced with polypropylene fiber (FR-3DPC). The effect of increasing the silica fume utilization ratio in FR-3DPC on the compressive strength (CS), flexural strength (FS), and drying-shrinkage (DS) performance of the mixtures was also examined. A total of five FR-3DPC mixtures were produced using silica fume at the rate of 3, 6, 9, and 12% of the cement weight, in addition to the control mixture without silica fume. As a result of the tests, the dynamic yield stress value decreased with the addition of 3% silica fume to the control mixture. However, it was found that the dynamic yield stress and apparent viscosity values of the mixtures increased with the addition of 6, 9, and 12% silica fume. With the increase in the use of silica fume, the CS values of the mixtures were generally affected positively, while the FS and DS behavior were affected negatively.

Analisis Kuat Tekan Beton dengan Pemanfaatan Silica Fume dan Fly Ash Sebagai Pengganti Semen Sebagian

Construction activities require concrete as a widely used material. Concrete consists of several compositions, namely fine aggregate, coarse aggregate, water, and Portland cement as the main material for the binder. Cement production contributes around 6% of carbon emissions which can damage the environment, including global warming, and the use of high levels of cement material in concrete mixtures, so alternative materials are needed to replace cement or cement additives for concrete mixes. Alternative materials used in this research are fly ash and silica fume. This research aims to determine the test results and characteristics of concrete using silica fume and fly ash as partial cement substitute materials as well as the effect of the ratio of silica fume and fly ash on the compressive strength of concrete. The research was carried out by direct testing in the laboratory. The various mixtures of Fly Ash (FA) and Silica Fume used are: FA 10% and SF 5%, FA 15% and SF 5%, FA 20% and SF 20%, FA 25% and SF 10%. Based on the results of compressive strength tests carried out at 28 days of concrete, it shows that the use of silica fume and fly ash to replace cement cannot be said to have succeeded in increasing the strength of the concrete. The highest compressive strength value was achieved by variation 3, namely with a fly ash content of 20% and 10% silica fume, producing a compressive strength value of 19.44 Mpa, this shows that the strength achieved is still limited to low quality concrete below 20 Mpa.

Penggunaan Silika Fume Untuk Reduksi Semen Dengan Limbah Granit Sebagai Pengganti Agregat Kasar Terhadap Kuat Tekan Dan Kuat Tarik Beton

Concrete is a mixture of cement, sand, gravel, and water. In order to obtain good quality in the process, added ingredients, waste, or other materials with a certain ratio value are added. In this case, the use of granite waste as a substitute for coarse aggregate that is easy to find and the use of silica fume which aims to increase the compressive strength of concrete. The purpose of this study was to determine the effect of granite waste and silica fume, as well as the relationship between compressive strength and tensile strength of concrete with these variations. The percentage of granite waste and silica fume varied, ranging from 5%-10% granite waste and 0%, 7.5%, 15%, 22.5%, and 30% silica fume. Concrete testing was carried out after the concrete was 28 days old. The planned compressive strength is 25 Mpa. From the results obtained, the average normal concrete compressive strength was 27.69 Mpa and the average normal concrete tensile strength was 3.14 Mpa. The addition of 5% - 10% percentage granite waste and 0% silica fume obtained an average compressive strength of 27.74 Mpa and 27.65 Mpa, and an average tensile strength of 3.18 Mpa and 3.16 Mpa. The percentage of 10% granite waste and silica fume 7.5%, 15%, 22.5%, and 30% obtained average compressive strengths of 26.42 Mpa, 26.33 Mpa, 25.10 Mpa, and 25.01 Mpa respectively and average tensile strengths of 2.71 Mpa, 2.64 Mpa, 2.50 Mpa, and 2.41 Mpa respectively.

Use of silica fume as a replacement of cement in the concrete

Over the past 30 years, significant advancements have been made in enhancing the capabilities of concrete as a construction material, with a focus on high-strength concrete applications using Silica Fume (SF). Global interest in SF as a pozzolanic admixture has surged owing to its ability to enhance concrete properties when used at specific percentages. This study examined the effect of addition of SF in concrete mixes. The performance of concrete in corrosive environment is most important and it can be enhanced by the addition of SF. For strength and longevity, hight strength concrete is required. In this study, concrete was prepared with varying proportions of silica fume (5, 10, and 15% by aggregate volume). The specimens were tested to evaluate their strength. The cubes and beams were casted, cured and tested on universal testing machine. The findings showed that both the compressive and flexural strengths were improved by the addition of silica fume. The mechanical and durability properties of concrete are significantly enhanced by the incorporation of silica fume. The findings of this study are helpful for construction industry in the use of silica fume as an economical choice for the enhancement of strength.

Replacing fly ash with a natural pozzolan in normal strength concrete and ultra-high performance concrete

Fly ash is a widely-used supplementary cementitious material (SCM) in concrete. Common reasons for using fly ash in normal strength concrete (NSC) are to reduce cement consumption and mitigate alkali-silica reaction. Additionally, fly ash is being used in ultra-high performance concrete (UHPC) to reduce use of silica fume which is more expensive than fly ash. Fly ash and silica fume are important SCMs in UHPC that provide a dense microstructure, improving UHPC strength and durability. However, fly ash is becoming less available because the energy industry has been investing in renewable energy production and removing coal burning power plants from operation. Therefore, there is a need to identify sustainable SCMs to replace fly ash in NSC and UHPC mixtures. Natural pozzolans are a diverse class of siliceous or siliceous and aluminous materials that can form compounds possessing cementitious properties in the presence of water. Since natural pozzolans are easily mined, they are usually considered to be more sustainable than Portland cement and nearly as sustainable as other SCMs such as fly ash and silica fume. This experimental study evaluated the effects of a natural pozzolan (pumicite) as a potential replacement for fly ash that can produce comparable rheological and mechanical properties in NSC and UHPC mixtures. Results indicated that workability of both NSC and UHPC mixtures containing pumicite was consistent enough to achieve the targeted workability in just a few trials. Additionally, NSC mixtures with 30% pumicite had comparable compressive strength compared to NSC mixtures with 30% fly ash. Modulus of rupture (MOR) for NSC mixtures containing 30% pumicite (greater than 4.10 MPa) exceeded the MOR for specimens containing 30% fly ash. For UHPC mixtures, results showed that up to 75% of the fly ash in the control mixture could be replaced with pumicite while still producing acceptable compressive and flexural strengths. Based on these results, it appears that pumicite can be a reliable alternative for fly ash in NSC and UHPC mixtures in terms of rheological and mechanical properties.

EXPERIMENTAL STUDY ON STRENGTH OF CONCRETE USING NANO SILICA

Thetestonhardenedconcreteweredestructivetestoncubeforsize(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) at 7,14,28 days of curing as per IS: 5816-1999.The main objective of this work is to study the suitability of the silica fume as a pozzolonic material for cement in concrete. However it is expected that the use of silica fume in concrete improve the strength properties of concrete. In this study the combination of 5% nano silica 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 40%increase in the flexural and tensile strength of concrete.

Self-sensing properties of alkali-activated materials prepared with different precursors

The development of smart concretes with self-sensing properties has gained increasing attention recently. In this study, the effect of different precursors, including blast furnace slag, fly ash, silica fume, and metakaolin, on the electrical conductivity and piezoresistive properties of alkali-activated materials (AAMs) with and without carbon fiber (CF) was investigated. The experimental results revealed that the electrical and self-sensing properties of AAMs were significantly influenced by the raw materials, both with and without carbon fiber. However, distinct trends were observed. The use of silica fume (25 wt%) was beneficial to the self-sensing property of CF-AAM mortars. Mixtures containing fly ash and pure slag exhibited higher sensitivity but with reduced repeatability of the piezoresistivity. Due to the poor dispersion of carbon fibers, as well as the porous microstructure, mixtures with metakaolin had poorer conductivity and piezoresistivity. AAM mortars had evident piezoresistivity under cyclic loading, but their stability was inferior to that of AAM with carbon fibers. The pore size distribution and gel pore quantity of the binder phase were important factors determining the conductive and piezoresistive properties of CF-AAM mortars.

Synthesis and effect of using silica fume particles on shear properties of basalt fibers‐epoxy composites

AbstractIn this study, the effect of the addition of silica particles modified with silane agent on the mechanical properties of basalt fibers‐epoxy composites were studied with the interlayer shear strength (ILSS) test. In the first stage, silica fume particles were synthesized using the sol‐gel method and surface modified using tri mercaptopropyl trimethoxy silane agent. The results of the characterization showed that the synthesized powder is nanometric scale, amorphous and high purity. The surface‐modified silica fume particles (0, 2, 4, 6 wt.%) were distributed inside the epoxy matrix using a mechanical stirrer and ultrasonic waves. The hand lay‐up method was used to fabricate composite samples, then the effect of adding these particles on the mechanical properties of basalt fibers‐epoxy composites under interlayer shear loads was studied. The results of the research indicated that the addition of silica fume particles has a significant effect on improving the mechanical properties of basalt fibers‐epoxy composites, and the greatest improvement in mechanical properties was achieved by adding 4 wt.% of modified silica fume particles. In the case of composites without SF particles, the shear strength was 34 MPa, which was increased to 40 MPa by adding 4 wt.% of SF particles (about 20% improvement). On the other hand, results demonstrated that the optimal distribution of silica fume particles within the polymer matrix performs an impressive role in improving the mechanical response of composite samples.Highlights The use of silica fume in the polymer composite is one of the research innovations. Silica fume is a super‐fine spherical powder that is collected as a by‐product. The silane is used to better distribute and optimal interaction of the silica fume in epoxy. Sol‐gel is one of the methods to synthesis of silica fume. ILSS test was done to investigate the strength of the interface of basalt fibers and epoxy.

Effects of Industrial and Agricultural Recycled Waste Enhanced with Lime Utilisation in Stabilising Kaolinitic Soil

Soft kaolin clay is a problematic soils encountered in various construction projects that lead to the implementation of soil stabilisation. On the other side, the massive production of industrial and agricultural waste currently presents a critical problem for the environment. However, the utilisation of industrial and agricultural wastes in altering the characteristics of kaolinitic soil can be considered as an ideal solution to enhance the characterisation of problematic soils in the field of construction. Therefore, this study examines the alterations of the engineering properties of soft kaolin clay by utilising silica fume as the industrial by-product and eggshell ash as the agricultural by-product enhanced with lime use. To assess the impact of silica fume, eggshell ash, and lime on the various characteristics of kaolinitic soil, a series of laboratory experiments containing Atterberg limits, specific gravity, compaction test, unconfined compression test, X-ray fluorescence, X-ray diffraction, sieve analysis, and field emission scanning electron microscope is carried out. In this study, 2%, 4% and 6% of silica fume, 3%, 6% and 9% of eggshell ash and lime and the optimal combination of SF, ESA with 3%, 6% and 9% of lime are usedand were cured for 1, 7, 14 and 30 days. The results present that the optimal utilization of silica fume, eggshell ash, and lime can alter the engineering characteristics of the soft kaolin clay by reducing the specific gravity, consistency limits, linearshrinkage, and maximum dry density, while increasing the value of shrinkage limit, and optimum moisture content. In terms of strength improvement, the highest unconfined compression strength was recorded when soft kaolin clay was treated with 6% silica fume, 6% eggshell ash and 9% of lime for four (4) different days of curing with a strength improvement of 81.03%, 82.46%, 88.49% and 88.74%. Therefore, this study concludes that optimal use of silica fume, eggshell ash, and lime can persistently alter the characteristics of kaolinitic soil and open the way to economical and sustainable materials in improving the problem soil.

Experimental Analysis of High-Strength Concrete Using Granite Aggregates

The present study investigates the effect of incorporating metakaolin and silica fumes in the production of high-strength concrete along with partial replacement of coarse granite aggregates in the high-strength concrete. The higher compressive strength, refined microstructure, and decreased permeability of high-strength concrete are some of the properties responsible for its trending use in the modern construction industry. The main purpose of this research is to evaluate the effect of the replacement of coarse granite aggregates with natural aggregates on the mechanical and durability properties of high-strength concrete. For understanding the effect of metakaolin, silica fume, and granite aggregates on the properties of high-strength concrete, various specimens such as cubes, cylinders, and cylindrical discs were cast and tested after 7, 14, and 28 days of curing. Various concrete mixes were prepared by adding silica fume at 5%, 7.5%, and 10% and metakaolin at 5%, 7.5%, 10%, 12.5%, and 15% in concrete production. Furthermore, High-strength concrete mixes were also prepared by replacing natural coarse aggregates with granite coarse aggregates by 25%, 50%, 75%, and 100% to study the effect of replacement percentage on the concrete properties. Test results indicated that the compressive strength and split tensile strength of the concrete mix increased with the increase in the replacement percentage of granite aggregates, with the highest strength seen at complete replacement with granite aggregate due to the enhanced compressive strength of such aggregates in comparison with the natural coarse aggregates. In various mixes cast using metakaolin and silica fume, the highest compressive strength was seen in a mix containing 10% metakaolin and 7.5% silica fume, and results of other mixes indicated that the use of silica fume and metakaolin are viable options for high-strength concrete production in our experimental study.

Preparation, mechanism, and application of silica fume–steel slag composite cementitious material based on the D-optimal mixture method

Steel slag and silica fume as cementitious materials to replace cement have been subjected to many recent investigations. However, the optimization of the mix ratio of silica fume–steel slag composite cementitious materials has rarely been reported. This study aims to design and optimize a novel composite cementitious material of the steel slag–silica fume–ordinary Portland cement (SSP) using the D-optimal mixture design (DOD) method. A DOD model was developed to determine the optimal mix ratio of SSP. Microscopic tests were conducted to investigate the synergistic effect of SSP. The mechanical properties of SSP-stabilized macadam and stone chips were evaluated using unconfined compressive strength (UCS), water stability, and split strength tests. The results indicate that the optimal content of steel slag in SSP was determined to be 16.238%, and that of silica fume was 1.917%. Silica fume consumes the Ca(OH)2 generated during hydration, and as a filler, it also provides nucleation sites for hydration reactions, promoting the secondary reaction to generate calcium silicate hydrate (C–S–H) gels wrapped around the steel slag particles, optimizing the pore structure and reducing the porosity of SSP. The SSP promoted the development of mechanical strength in the later stages. The greatest growth observed in SSP-stabilized stone chips, from 7 days to 28 days of curing, the UCS, water stability coefficient, and split strength increased by 62.6%, 9.9%, and 71% respectively. A significant correlation was observed between UCS and split strength, with UCS being approximately 9.0 to 9.8 times higher than the split strength. This study contributes to the optimal design of similar solid waste composite materials and provides a reference for the use of silica fume and steel slag in road construction.

SHEAR CAPACITY OF REINFORCED CONCRETE BEAMS WITHOUT SHEAR REINFORCEMENT: A REVIEW

Shear failure in reinforced concrete beams has gained excessive study, particularly beams without stirrups. Because shear failure is considered the most serious due to it occurring suddenly without warning. Because of the seriousness of the matter concerning shear failure, many researchers are looking to use additive materials that differ from traditional concrete constituents in order to improve the shear resistance of the beams, such as the use of silica fume, steel fiber, metakaolin, and many others. The current studies focused on understanding the resistance provided by the interlocking forces between the aggregate and that provided by the non-cracked compression zone, with the use of some materials that are intended to improve the properties of concrete. This paper presents a review of the previous literature that included studying the mechanism and behavior of shear failure of concrete beams without web reinforcement and also includes a presentation of the most important equations used to predict the shear capacity of concrete beams, especially those without stirrups, to understand the mechanism of failure and to know the most important factors affecting the failure of shear.

Comparative optimization of densified system of ultra-fine particles (DSP) and Horsfield filling toward UHPC fabrication

Using small size particle as secondary filler to fill in the gap between cement particles according to either DSP or Horsfield filling theory will optimize the packing structure, thereby enhancing the properties of UHPC. However, there are key differences between the two theories regarding to the ratio between the particle size of cement and secondary filler, making it questionable to improve the performance of UHPC. Herein, we developed DSP guided UHPC and Horsfield inspired UHPC via the use of silica fume and fly ash microsphere, respectively, we compared and evaluated the packing structure and corresponding performance. We found that less well-known method Horsfield filling theory contributed to the overall best performers of UHPC compared with that of DSP inspired UHPC. 1H NMR spectra and wet packing density calculation results demonstrated that Horsfield packing contributed to a more homogeneous and denser microstructure, and significantly reduced autogenous shrinkage, cost, and energy burden compared with that of DSP-modified UHPC. We also found that typical DSP fell far short of its theoretical state due to SF agglomeration. This study explores the potential of Horsfield packing in optimizing the packing structure of UHPC, providing an economical option for enhancing the performance of concrete.

Study of Microstructure, Crystallographic Phases and Setting Time Evolution over Time of Portland Cement, Coarse Silica Fume, and Limestone (PC-SF-LS) Ternary Portland Cements

The use of silica fume as a partial replacement for Ordinary Portland Cement provides a wide variety of benefits, such as reduced pressure on natural resources, reduced CO2 footprint, and improved mechanical and durability properties. The formation of more stable crystallographic phases in the hardened cement paste can promote resistance to concrete attacks. However, using coarse silica fume may result in lower expenses and shorter workdays. In this work, coarse silica fume was used as a partial replacement of cement, by weight, at 3%, 5%, and 7%, and it was used as limestone filler at different particle sizes. The size of coarse silica fume used was 238 μm. The microstructural, compositional analysis, and crystalline phase content of mixed cements at different ages were evaluated. The addition of coarse silica fume and limestone promoted pore refinement of the composites and increased the calcium and silica content. The filling effect of fine limestone and coarse silica fume particles, as well as the formation of CSH gel, was found to be the main reason for the densified microstructure. The contributions of combined coarse silica fume and limestone improve the stability of CSH gels and pozzolanic reaction.

A comprehensive assessment of mechanical and environmental properties of green concretes produced using recycled concrete aggregates and supplementary cementitious material.

This study aims to present a multi-perspective evaluation of green concretes produced using supplementary cementitious material and recycled concrete aggregates and to balance the reduction in compressive strength values caused by using recycled concrete aggregates with silica fume. For these purposes, statistical analyses were performed on the response surface method using the data of 9 reference and 27 green concrete series mixtures, and mathematical models were developed to predict the compressive strength with high accuracy. Then, energy consumption, global warming potential, and waste generation were taken into account from the environmental impact categories, and the environmental impact scores obtained were compared in detail to examine the impact of the use of silica fume and recycled concrete aggregates on sustainable development. Significant reductions in energy consumption and global warming potential values with the use of silica fume and waste generation values with the use of recycled concrete aggregates were achieved, and it was seen that supplementary cementitious material and recycled concrete aggregates are of great importance in terms of sustainable development. It was seen that these waste materials could be utilized, especially in regions with high earthquake risk, and that these waste materials are of great importance.

Sustainable use of silica fume in green cement concrete production: a review

Sustainable use of silica fume in green cement concrete production: a review

Pengaruh Penggunaan Silica Fume Sebagai Bahan Tambah Pada Beton Alir

Concrete is a material that is commonly used when doing construction work today. Because concrete has several advantages when compared to other materials, such as being easy to form, resistant to weather changes, has high compressive strength, and is durable. In this study the use of Silica Fume as an additive to flow concrete has the function of improving the quality of flowing concrete. Silica Fume has an important role in affecting the chemical and mechanical properties of concrete. Judging from its chemical properties, Silica Fume geometrically fills the voids between cement materials, and causes the pore diameter to decrease and the total pore volume to decrease. Meanwhile, from its mechanical properties, Silica Fume has a pozzolanic reaction (a material containing silica/silica dioxide and alumina compounds) which reacts to the limestone released by the cement. The aim of the research is to increase the maximum compressive strength of flowing concrete by using Silica Fume added with varying percentages of 0%, 5%, 6%, 7.5%, 9%, 10.5% and 12% and using a superplasticizer of 1.5 %. From the results of the research conducted, it was found that flowing concrete with added silica fume on concrete compressive strength was able to reach 7.5% at 7 days of age of 25.91 MPa and at 28 days of concrete age was obtained at 26.19 MPa.