Substitution Of Cement Research Articles

Effect of Substitution of Cement by Mineral Powders on the Physicomechanical Properties and Microstructure of Sand Concretes

The approach that contributes to the development of eco-materials in construction is the use of mineral powders, which can improve mechanical properties and reduce cement consumption. This article aims to study the effect of substitution by mass of cement with mineral powders on the physicomechanical properties and microstructure of sand concretes. The used mineral powders are A: the limestone, B: the natural pozzolan, C: the hydraulic lime, D: (1/3 limestone + 1/3 natural pozzolan + 1/3 hydraulic lime), and E: (1/2 natural pozzolan + 1/2 hydraulic lime). The studied percentages are 5%, 10% and 15%, in both separated and combined states. The studied properties are workability, compressive strength, the elasticity modulus in compression, shrinkage and microstructure analysis. The objective is to target the optimal percentage of the substitution of cement with mineral powders, which ensures the best compromise between the main properties of the studied sand concretes. The obtained results show that the optimal percentage is in favor of the substitution of cement by 10% D (1/3 limestone, 1/3 natural pozzolan and 1/3 hydraulic lime). Even the 15% of mineral powder D, presented similar performances compared to the sand concrete (without mineral powders). Finally, in the context of the development of eco-materials, it should be noted that the 10% D and 15% D (1/3 limestone, 1/3 natural pozzolan and 1/3 hydraulic lime) contribute to decrease the use of cement and consequently to reduce of CO2 emissions.

Towards greener ultra-high performance concrete based on highly-efficient utilization of calcined clay and limestone powder

In this study, greener ultra-high performance concrete (UHPC) is designed and prepared based on calcined clay-limestone powder, aiming to increase the cement substitution level while ensuring the excellent mechanical properties of UHPC. Compressive strength tests, X-ray diffraction, thermal gravity-differential thermal gravity, isothermal calorimetry, and mercury porosimetry were used to characterize the mechanical properties, hydration and microstructure development of the samples, revealing the effect of the calcined clay and limestone powder on the performance of UHPC. The results show that when the substitution level is lower than 40%, the composition of raw materials has no obvious effect on the strength at the early stage, and the early mechanical properties decrease at the higher substitution level, but the mechanical properties at 28d are still comparable to or even higher than the reference sample. Especially, when the overall substitution level is 60% and the ratio of calcined clay to limestone powder is 2:1, the compressive strength exceeds that of the reference sample at 28d. Through this study, a feasible way for the design and preparation of greener UHPC is proposed based on calcined clay and limestone powder cementitious material system.

Concrete made from waste paper sludge (WPS): a sustainable material

PurposeThe growing quantity of waste is a worrying reality that has resulted in environmental sustainability challenges. Waste paper sludge (WPS) in large quantities from paper mill industry are produced every year. Their disposal in landfills, in general, pollutes the environment. Cement manufacture also contributes to global warming by emitting carbon dioxide. As a result, a novel use of industrial wastes as a supplemental cementitious ingredient in concrete formulation can help to mitigate the environmental problem. This paper aims to study the possibility of usage of WPS as partial replacements of cement for sustainable development of concrete.Design/methodology/approachThis study aims at testing the mechanical properties of concrete that has been mixed with WPS. Between 5% and 20% of the weight of cement, WPS was used to substitute it. The water binder ratios of 0.55, 0.50, 0.45 and 0.42 were all considered for an experiment to better understand the impact of WPS on concrete. In terms of workability, density, water absorption (WA), compressive strength (CS) and flexural strength (FS), concrete mixtures were created, tested and compared to traditional concrete mixes.FindingsAccording to the findings, the initial and final setting times of the concrete mixtures were both significantly delayed, and the workability and density of the concrete mixtures were both significantly lowered at all water binder ratios and replacement levels. Both compressive and FS of concrete made with WSP declined significantly at all water binder ratio. Substitution of cement by WPS enhanced the WA of all the concrete mixes. The mechanical performance of concrete mixtures that were made with a replacement level of 5% exhibited noticeable improvements. Whereas the more is the replacement levels the more the loss in the mechanical properties were noted. The ideal replacement levels for the WPS are up to 5% only.Originality/valueThis paper contributes to the literature by exploring the ecological and sustainable effects of using WPS in construction materials.

Wood waste ash Re-Use. Mechanical performance and durability for mortars

Wood waste ashes from a thermal biomass heating plant were used as a supplementary cementitious material in partial substitution of ordinary Portland cement. The ashes undergone a chemical analysis with respect to their heavy metal content. They exhibited values below the required legislation limits and could be used for the tests. Mechanical and durability tests were carried out on mortars specimens with the addition of wood waste ashes to ordinary Portland cement (OPC) in percentages of 5, 15, and 30%. The strength properties of mortar mixtures increased with age due to pozzolanic actions. This was observed with the 5–15% WWA addition. The OPC reference blend with 5% WWA in substitution of cement exhibited the best data and a satisfactory durability. The values obtained were similar or below the required limits for the resistance as compared to the mortars prepared with the reference Portland cement.

Influence of rice husk ash and bagasse ash on durability of concrete

The increase in global demand of concrete has put forth numerous challenges in the form of durability and sustainability. The cement industry has emerged as one of the leading contributors of pollution and global warming. As such, use of various supplementary cementitious materials including fly ash, coal bottom ash, rice husk ash, sugarcane bagasse ash etc. has gained importance to tackle those challenges. In this study, three different concrete mixes were prepared by 10% cement substitution with rice husk ash (RHA) and sugarcane bagasse ash (SCBA) to study their impact on the durability of concrete. It was observed that these materials enhance concrete’s pore structure through pozzolanic reactions, thereby increasing its resistance against corrosion and water absorption by restricting the fluid transfer. It was also observed that the 28-day RCPT value was found decreased by 58% for 10% RHA replacement while as 9% decrease was observed by 10% SCBA replacement. Also, it was observed that no carbonation occurred in RHA and SCBA blended mixes after 56 days of CO2 exposure. Electrical resistivity was found highest in RHA mix at 28 and 56 days curing while as 90 days resistivity was highest in SCBA concrete. The initial surface absorption test (ISAT) values were found to be reduced by 50% and 61% respectively for RHA and SCBA concrete mixes. Similarly, the rate of water absorption was lowest in RHA blended mix.

Strength characteristics of concrete using waste materials

In today's construction world, sustainability is a widely acknowledged idea. The construction industry is innovating in terms of technology and materials utilized as construction costs have risen and harmed the environment. In the present study, a balanced approach was used to have sustainable construction materials. The study involves using ground granulated blast-furnace slag (GGBS) and coconut fibre (CF) to improve the concrete’s strength characteristics. The partial substitution of ordinary Portland cement (OPC) with GGBS and CF was investigated. The strength characteristics of concrete i.e., compressive, and tensile strength were measured by having a proportion (1.75%) of CF and the impact of GGBS with varied proportions (25%, 50%, 75%, and 90%). The study reveals that cement when partially replaced with GGBS at 75% and CF at 1.75% improved the strength characteristics of concrete to 11.38% and 15.26%, respectively. The current study presents the various experimentation details and analyzed observations to have an effective conclusion about the utilization of natural fibre in concrete.

Evaluation of pozzolanic activity of ternary blended supplementary cementitious material with rice husk ash and GGBS

The utilization of industrial and agricultural waste materials as supplementary cementitious material in blended cements provides an adequate solution for reducing the greenhouse emission and the environment concerns associated with waste management. Few literatures have been reported on the partial substitution of cement with the blended usage of mineral admixtures such as GGBS and RHA in cement mortars. The effect of blended usage of the mineral admixture as partial replacement of cement are investigated based on the physical and pozzolanic properties of ternary blended cement mortar. An optimal proportion of RHA -GGBS blended supplementary cementitious material is proposed based on strength activity index for utilizing them in ternary blended cement. The blended supplementary cementitious material with 30% rice husk ash and 70% ground granulated blast furnace slag as constituent materials are identified as the optimal proportion for achieving better pozzolanic activity.

Sustainability aspect of possible material substitution in construction industry

While creating the sustainable construction systems it is crucial to innovate in production of construction materials by maximizing recycling and reuse of the materials during production and use of the buildings. The intention of this paper is to provide new insights and better understanding of sustainable oriented innovation in production of construction materials, in particular substitution of cement in mortar with waste material, fly ash, bearing in mind its huge negative impact on the environment. Previous investigations of possible use of fly ash have proven the possibility of its use for the production of cement for lightweight concrete, bricks, asphalt fillers, however the use of the fly ash in cement screeds was not considered.The aim of this work was to examine at first, justification of substitution of cement in mortar with fly ash due to its newly gained properties as change of density, compressive strength and water absorption. In order to take into account aspect of environmental protection the newly gained mechanical properties of the materials were tested in terms of its convenience for use in cement screeds.

IMPROVEMENT OF LATERITIC GRAVELLY SOILS IN ROAD CONSTRUCTION: PARTIAL SUBSTITUTION OF CEMENT BY GRANITE POWDER

This study focuses on the lateritic gravels of N'DOUCI whose physical properties do not meet the specifications for their use as a road base. Thus, for its use in road construction, a partial substitution of cement by granite powder has been made. Several tests (particle size analysis, chemical analysis, CBR and proctor tests, Atterberg limits, etc.) were carried out to verify the geotechnical and mechanical characteristics of the new material. This study showed that the addition of granite powder in place of cement improved the material properties, i.e. optimum dry density, CBR. The results show that the optimum dry density is 1.95% with a moisture content of 12%. Overall, the results obtained are satisfactory and show that a quantity of 2% cement for 6% granite powder is required for a base course material in road construction. However, it would be useful to use the proportions of 4% cement to 4% granite powder.

Evaluating the effect of steel fibers on the mechanical performance of high-volume fly ash concrete

The construction sector contributes significantly to environmental degradation by completely depleting energy resources. Cement industry emissions are the most significant contributors to climate change along with global warming. To address this issue, researchers are investigating different materials with cementing properties thereby replacing the cement in concrete either partially or completely. Various materials such as different types of ashes and slags have been effectively utilized as cement substitutes thereby making the concrete sustainable. Partial substitution of cement with fly ash has a positive impact on the overall performance of concrete but the incorporation of fly ash at a higher volume into the concrete reduces its characteristics. The objective of this work was to improve the overall performance of High-Volume Fly-Ash concrete by incorporating steel fibers with varying volume fractions. From this study, it can be inferred that reinforcing with steel fibers up to 1.2% fiber volume has compensated for the negative effect of HVFA by improving the overall properties.

The Influence of Polypropylene Fiber and Silica Fume on the Mechanical Properties of No-Fine Concrete with Recycled Aggregate

No-Fines Concrete is a type of concrete produced without fine aggregate or sand. Because of its high porosity, it allows rainwater to seep into the ground, directly replenishing the groundwater aquifer. With a design load of three tons, no-fine concrete can be utilized as pavement for rural roads. Additionally, this type of concrete can be utilized as a sub-base material in both flexible and rigid pavements. Aside from No-Fines Concrete's permeability properties, asphalt overlays are another option. This research studied the impact of silica fume and polypropylene fiber on the properties of no-fine concrete with recycled aggregate. The ratios of cement to aggregate and water to cement were 1:4 and 0.3, respectively. The recycled aggregate was demolished reactive powder concrete used in percentages of 10, 20, and 30% as a substitution for coarse aggregate by volume. The recycled aggregate percentage of 10% was the optimal percentage as it showed the least adverse effect on the no-fine concrete mixes. The polypropylene fiber was then added to the no-fine concrete mixes with 10% recycled aggregate in the percentages of 0.5, 1, and 1.5% by volume. The optimum percentage of polypropylene fiber was 0.5%, which improved the mechanical properties of no-fine concrete. Silica fume was used as a partial substitution for cement at a percentage of 10% and added to no-fine concrete mix with 10% recycled aggregate. The results show that using 10% silica fume and 0.5% polypropylene fiber with 10% recycled aggregate increased the splitting tensile strength, flexural strength, compressive strength, and modulus of elasticity by (22.54 and 40.32%), (22.22 and 35%), (21 and 35.37%), and (22 and 38.19%) compared to reference mix (NC) and the no-fine concrete mix with 10% recycled aggregate (RNC10), respectively. In comparison, the dry density was higher by (1.34%) than RNC10 and lower by (0.68%) than NC.

Behavior of self-compacting concrete by the addition of recycled aggregates and nano-silica

The construction industry is growing rapidly all over the world and busy in inventing the new construction materials. The existing construction materials which are used for constructions from past decades were accumulating on the land as a waste, due to lack of reutilizing the used materials. In this experimental work, efforts were made to re-utilize the recycled aggregates which are also called demolition waste aggregates. The current study is divided into two stages. The first stage of work examines the influence of recycled aggregates on the characteristics of self-compacting concrete (SCC). The second stage includes the substitution of cement by nano silica and replacement of normal aggregates by recycled aggregates (RA) in the SCC mix. In this study, natural aggregates are replaced by 10%, 20%, 35% and 50% with recycled aggregates by the weight of total aggregates. Nano silica (NS) is used in this study, which replaces the 0.5% and 1% by weight of cement for each partial replacement level of recycled aggregates. The workability tests were performed on prepared SCC mix. The workability properties were satisfying the requirements of SCC. The compressive, split tensile and flexural strength tests were conducted on hardened concrete. The microstructural configuration of SCC containing with and without RA & NS mixtures were examined using a scanning electronic microscope (SEM). The RCPT test was conducted to understand the durability of the SCC. The outcomes of mechanical properties were optimum at 35% replacement of RA in first stage of work. Similarly, mechanical properties were optimum at 1% of NS and 35% of RA in second stage of work. The SEM analysis reveals the micro structure of mixes, the nano silica replaced concrete mix exhibit the lesser voids compared to RA replaced concrete. It results shows that voids were filled with nano particles and enhances the performance of SCC mix.

Influencia de la bacteria megaterium en las propiedades de resistencia y durabilidad del hormigón parcialmente sustituido con metacaolín

El hormigón es uno de los materiales más utilizados en el sector de la edificación. Inevitablemente, el concreto gana fuerza y desarrolla grietas por contracción durante el proceso de curado. Las grietas por contracción proporcionan un punto de entrada para que los fluidos reactivos ingresen al núcleo de concreto. En condiciones favorables, los fluidos reducen el pH del núcleo y, en consecuencia, corroen las barras de refuerzo. Esta investigación muestra el uso de Bacillus Megaterium MTCC 3353, que produce carbonato de calcio y cierra las fisuras diminutas. En el estudio también se realizó la sustitución parcial de cemento por metacaolín. Se observó que las muestras de hormigón de base biológica mejoraron los parámetros de resistencia mecánica y durabilidad. La precipitación de calcita se validó mediante un estudio de microestructura. Los ensayos FESEM y XRD muestran la presencia de calcita (carbonato de calcio) en el interior de la estructura de hormigón. Se probó el crecimiento de las bacterias cuando se les añadieron superplastificantes. Las bacterias mostraron un crecimiento normal en comparación con las pruebas convencionales.

The influence of cement substitution with rice husk ash on high-strength concrete

High-strength concrete is a crucial construction material in modern infrastructure development. It involves replacing some conventional raw materials with environmentally friendly alternatives to enhance concrete quality. Rice husk ash (RHA) is an agricultural waste that contains natural pozzolanic materials capable of improving the mechanical properties and strength of concrete. The use of rice husk ash (RHA) in high-strength concrete mixtures has the potential to reduce cement consumption and enhance crack resistance. The aim of this study is to investigate the impact of substituting cement with rice husk ash (RHA) and adding superplasticizer on the compressive strength of concrete. The targeted concrete strength is 45 MPa with variations of rice husk ash substitution at 5%, 10%, and 15% by weight of cement. This research obtained the compressive strength of concrete at 7 days with variations of 5% at 30.59 MPa, 10% at 25.20 MPa, and 15% at 20.77 MPa. Subsequently, at 14 days, the compressive strength increased with variations of 5% at 37.48 MPa, 10% at 27.56 MPa, and 15% at 22.23 MPa. The compressive strength continued to rise at 28 days, with variations of 5% at 44.26 MPa, 10% at 29.36 MPa, and 15% at 29.19 MPa.

Influence of mineralogy and calcination temperature on the behavior of palygorskite clay as a pozzolanic supplementary cementitious material

Aiming to limit carbon dioxide (CO2) emissions by cement production and widen the supplementary cementitious materials' (SCM) resource options, recent research has been focused on developing the pozzolanic properties of low-cost calcined clays containing a blend of clay minerals and impurities as an alternative to metakaolin. This study investigated the effects of mineralogical composition and calcination temperature on the use of calcined palygorskite clays as SCM. Rietveld quantitative X-ray diffraction (RQXRD), thermogravimetric analysis and Fourier-transform infrared proved useful in shedding light on the relation of mineralogical composition and thermal treatment temperature of clays, with the properties of pastes and mortars, in which the calcined palygorskite clays substitute cement, at 20 wt%. The results indicated that with increasing palygorskite content in raw clays, the pozzolanic reactivity of calcined clays also increases. Moreover, the calcination of Mg – rich clays between 600°C and 750°C, presented higher calcium hydroxide (CH) consumption and strengths after 28 and 90 days of hydration compared to Al – rich ones. The former displayed the highest pozzolanic reactivity when calcined at 750°C, whereas the latter at 700°C. The substitution of cement by clays calcined at 750°C, and by metakaolin, resulted in a similar reduction of CH content in pastes; up to 60%, relative to neat cement, at all hydration ages. Calcined palygorskite clay could be introduced as a reactive pozzolan in mortar with comparable or higher strengths than neat cement counterparts.

Mechanical strength and durability analysis of mortars prepared with fly ash and nano-metakaolin

Pozzolans such as fly ash (FA) and nano-metakaolin (MK) are the two industrial wastes that have attracted the attention of researchers due to their pozzolanic action that improves the performance of cementitious materials in an aggressive environment and can reduce global cement demand and lessen the emission of greenhouse gases. This study analyzes the strength and durability properties of cement mortar with partial substitution of cement with MK in the presence of FA. The effect of substitution of MK in binary and ternary blends on strength and durability has been studied by varying the dosage of FA (5‐20%) as well as MK (2.5‐10%) and optimization of MK content has been carried out. A comparative analysis of beneficial aspects of FA and MK, along with their combination in optimized content at a fixed water/binder ratio of 0.5, has also been performed in terms of corrosion resistance through electrical resistivity and half-cell potential measurements. Further, the results have been correlated by microstructural analysis. The study reveals a significant increase in strength and durability of mortar at a dosage of 10% FA+7.5% MK with an increase in chloride, sulfate and corrosion resistance due to improved microstructure owed to the better pozzolanic action of the substituents with synergistic action. Thus, the partial substitution of cement with optimized content of MK (7.5%) in the presence of FA (10%) can not only help in solid waste management but can also reduce the cement consumption leading to sustainable construction.

Behaviour of High-Performance Fibre Reinforced Concrete Composite Short and Slender Columns under Uniaxial Compression

This paper describes the experimental studies carried out on the RC short and slender columns of bagasse ash blended HPC with influence of steel fibre (STF) and polypropylene fibre (PPF)are presented. The concrete was considered for M60 grade as recommended by P.C.Aitcin. The mix included both free steel fibre and polypropylene fibre, and furthermore the hybridization of steel fibre and polypropylene fibre at a total volume fraction of 1.0% by volume of concrete with 10% bagasse ash as a substitution of cement. Behaviour of eleven HPFRCC of each short and slender column with steel fibre, polypropylene fibre and hybrid fibres was examined. The behaviour of each column was assessed and presented with respect to load carrying capacity. The numerical studies were done using ABAQUS 6.9 to validate the experimental results.

Mechanical behaviour and environmental benefit of eco-friendly steel fibre-reinforced dry UHPC incorporating high-volume fly ash and crumb rubber

This study evaluates the impact of high-volume fly ash (HVFA) and waste crumb rubber (CR) on the mechanical property and environmental benefit of steel fibre-reinforced dry UHPC (FR-DUHPC) designed in a previous study. FA was introduced at 20–60% by mass substitution for cement with fibre dosage of 1.5 vol. %. Then, waste CR with different meshes were added as partial/completed replacements of coarse and medium sand with three volume contents of fibres (0.5%, 1.0% and 1.5%). Test results indicated that in the case of 1.5% fibre reinforcement, the increase in FA content and the addition of CR aggregate markedly reduced the density, modulus of elasticity and strength behaviour, whereas had minimal effect on the post-peak ductility of the assessed mixtures under compression and bending loads. Owing to the adopted moist/steam curing and the continuous pozzolanic reaction, the contribution of FA effect to both strengths at various ages was apparently increased and 50% of cement substitution was considered to be the most suitable FA addition in this study. For rubberized concrete reinforced with 0.5–1.5% steel fibres, the mechanical properties increased gradually with fibre dosage and curing age. However, the effect was evidently weakened with the addition of finer CR aggregate, and increasing the fibre dosage contributed to more positive impact on ductility rather than the load-carrying capacity. In summary, the flexural property benefits derived from the inclusion of steel fibre, FA and waste CR, as well as the eco-friendly benefits derived from the cost saving, energy conservation and carbon emission reduction, render the developed lightweight concrete mixture to be broadly used in dry concrete applications with different strength requirements that are mainly subjected to bending loads during serviceability.

Palm oil fuel ash as a sustainable supplementary cementitious material for concrete: A state-of-the-art review

New progress in recycling processes has resulted in the conversion of non-renewable materials to partially renewable resources. in this regard, the role of employing supplementary cement-based ‎materials in the concrete is significant to avoid excessive waste ending in landfills. There ‎are ‎numerous by products and wastes of have an immense value in the production of environmentally friendly concrete. In terms of application, the literature has highlighted the enormous potential of palm-oil fuel ash (PFA) as an alternative material in green concrete. PFA has been frequently used in the substitution of cement in concrete production to minimize the cost, health risk, energy consumption, and environmental degradation associated with cement production. Moreover, recycling by products and wastes aid in alleviating issues related to waste material disposal. The goal of this paper is to offer a state-of-the-art review of the published academic studies on the use of PFA in concrete and its impact on the workability, compressive strength (CS), splitting tensile strength (STS), and durability of concrete. Also, this paper aims to investigate the effect of PFA on sustainability by a scanning electron microscope (SEM) analysis of the micro-structure of concrete. The results indicate that using PFA with partial substitution improves workability and CS while decreasing STS and water absorption (WA). Furthermore, this study underscores the need for future research developments in this field.

Thermal Characterizations of Waste Cardboard Kraft Fibres in the Context of Their Use as a Partial Cement Substitute within Concrete Composites.

The building and construction industry consumes a significant amount of virgin resources and minimizing the demand with alternative waste materials can provide a contemporary solution. In this study, thermal components of kraft fibres (KFs) derived from waste cardboard are investigated. The mechanical properties containing KFs within concrete composites are evaluated. Metakaolin (MK) and KFs were integrated into concrete samples as a partial substitute for cement. Silica Fume (SF) was applied to the KF (SFKFs) with a view to enhancing the fibre durability. The results indicated that there was a reduction in compressive strength of 44 and 56% when 10% raw and modified KFs were integrated, respectively. Raw, fibre and matrix-modified samples demonstrated a 35, 4 and 24% flexural strength reduction, respectively; however, the tensile strength improved by 8% when the matrix was modified using MK and SFKF. The morphology of the fibres was illustrated using a scanning electron microscope (SEM), with an energy dispersion X-ray spectroscopy (EDS) provision and Fourier transform infrared spectroscopy (FT-IR) employed to gain insights into their chemical nature. The thermal, calorimetric and combustion attributes of the fibres were measured using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and pyrolysis combustion flow calorimetry (PCFC). SFKFs showed a lower heat release capacity (HRC), demonstrating a lower combustion propensity compared to raw KFs. Furthermore, the 45% decreased peak heat release rate (pHRR) of SFKFs highlighted the overall reduction in the fire hazards associated with these materials. TGA results also confirmed a lower mass weight loss of SFKFs at elevated temperatures, thus corroborating the results from the PCFC runs.