Replacement Of OPC Research Articles

Durability properties of cement – saw dust ash (SDA) blended self compacting concrete (SCC)

This paper report the durability properties of self-compacting concrete (SCC) modified with Saw dust ash (SDA) exposed to an aggressive media. Saw dust ash (SDA) was used to partially replace OPC in SCC at 0 - 30%. A number of trials mixes were conducted to obtain grade 40 SCC, with a suitable mix proportion varied at 5, 10, 15, 20, 25 and 30 % by weight of the binder as OPC replacement in SCC. Constant water to binder ratio of 0.37 with water reducing admixtures was used in all the mixtures. The research reveals that SDA enhanced the resistance of SCC against Na2SO4 attack at 5% replacement but performed poorly in H2SO4. The water absorption of SCC decreases with an increase in SDA content. The resistance of SDA-SCC to elevated temperature is reduced with an increase in SDA content. The compressive strength of the SDA-SCC decreases with the age of exposure in an aggressive media. The SEM result revealed the presence of crystal like spikes of SDA particles, which may contribute significantly to the high surface area of the ash particles and results in a porous structure at an early age.

Recycling of waste glass powder and tyre fiber in the development of eco-efficient concrete for high-performance structural application

Concrete suffers from several drawbacks due to the pollution associated with cement production, low tensile strength and low strain capacity that result in low resistance to cracks. Several attempts have been made to utilize waste materials for economical, sustainable construction and to improve concrete characteristics. This paper aims to investigate the effect of waste glass powder (WGP) as a partial replacement of cement and waste tyre fibre (WTF) as fibre reinforcement in the production of high performance concrete (HPC). ACI 211.1 was used to design a grade 50 HPC. At the first stage, WGP was introduced at a replacement level of 0 to 25 at a 5% interval by weight of OPC increment. Compressive strength at 3, 7, 28, 56, and 90 days of curing and slump flow was investigated, as well as establishing the optimum WGP content. WTF was then added to the optimal WGP-HPC in varying percentage addition of 0 to 2% at an increase of 0.4% by weight in the second stage. The compressive, splitting tensile, and flexural strengths at 3, 7, 28, 56, and 90 days were investigated. Slump flow was also investigated. It was discovered that the WGP is a suitable material for use as a pozzolana as it satisfied the minimum requirement given in ASTM C618. The compressive strength of HPC increased up to a 10% OPC replacement level by WGP before it starts declining. This signifies that the highest compressive strength was obtained at 10% WGP replacement level. It was also shown that adding the WTF decrease the slump flow and enhanced the compressive, splitting tensile and flexural strengths of WGP-HPC up to 1.2% and then dropped. Overall, an optimal HPC mix with 10% OPC replacement by GWP and 1.2% WTF addition outperforms all other mixes.

Fracture Toughness of Reactive Powder Fibrous Concrete Composites under Pure and Mixed Modes (I/III)

Reactive Powder Concretes (RPC) are well known for their exceptional strength properties and durability properties. The use of Supplementary Cementitious Materials (SCM) is the best way to enhance the strength and durability characteristics of RPCs further. Among various SCMs, the potential of Ground Granulated Blast-furnace Slag (GGBS) is proven by many researchers. However, the effect of GGBS on the fracture toughness of RPCs, especially under the tearing mode, is not explored. This study investigates the effect of partial replacement of OPC with GGBS in non-fibrous and fibrous RPCs, on its mode I (pure opening), mode III (pure tearing), and mixed-mode I/III fracture behaviour. A significant improvement in mode I, mode III, and mixed-mode I/III fracture toughness was observed due to incorporating GGBS and fibres in RPCs. The fibrous mix with 30% OPC, replaced with GGBS, exhibited the highest values of mode I and mode III fracture toughnesses, which were 2.35 MPa·m0.5 and 0.98 MPa·m0.5, respectively, and significantly high compared to the control non-fibrous and fibrous RPC mixes. The study reveals the ability of GGBS as an SCM to improve the fracture toughness of RPC mixes, thereby delaying the failure of the process of structural components.

Effect of Palm Oil Fuel Ash and Eggshell Waste Powder on Compressive Strength and Heat of Hydration for Concrete

The aim of the research is to use palm oil fuel ash (POFA) and eggshell waste powder (ESP) as OPC replacement in concrete. The effects of POFA-ESP on compressive strength and heat of hydration was investigated. These materials were sieved through 45 µm to obtained the similarly OPC particles. The cement replacement of 20% with POFA-ESP was considered. Based on optimum results, the mix proportion of POFA 10% + ESP 10% achieved the optimum compressive strength at 28 days. However, the OPC concrete had the highest compressive strength. In hydration reaction of concrete, the concrete incorporating of 10% POFA+10% ESP has recorded with the highest peak temperature, while the temperature of OPC concrete recorded lower than 10% POFA+10% ESP. It differs from the concrete containing 20% POFA, which has the lowest temperature gains when compared to OPC concrete. It has been observed that the POFA has a low CaO composition. It has been found that the POFA is known has a low composition of CaO. The higher CaO composition is known to have occurred in ESP. This led to higher calcium hydroxide, Ca(OH)2 produced during the hydration process and therefore did not control the heat released from the hydration temperature.

Water Permeability, Strength Development And Microstructure of Activated Pulverized Rice Husk Ash Geopolymer Cement

The activated pulverized rice husk ash (PRHA) as a pozzolanic material mixed with Portland cement (OPC) in various ratios was synthesized as geopolymer cement. The alkaline activator was prepared from a mixture of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Effect of OPC replacement on the various properties of the synthesized geopolymers was evaluated. The results showed that the water of consistency sharply decreased with the increase of the OPC addition, while the setting times (initial and final) slightly decreased. The water absorption and apparent porosity reduced with OPC replacement at the expense of PRHA merely up to 18 wt. % content, and then increased. The bulk density as well as flexural and compressive strengths improved and enhanced also up to 18 wt. % OPC content, but then declined with any further increase. The free lime content increased up to 3 days of curing and then decreased onward due to its consumption during the pozzolanic reactions. The 18 wt. % OPC geopolymer mix is the optimum mix, where it achieved the better water absorption (6.89 %), bulk density (1.9099 g/cm3), apparent porosity (15.62 %), flexural strength (5.54 MPa) and compressive strength (58.25 MPa) at 90 days curing times. The ultrasonic pulse velocity test largely confirmed the obtained physical and mechanical characteristics. The FTIR spectra showed that the spectra of G18 geopolymer was more pronounced due to the formation of NASH geopolymer-gel needed to ensure better conformity between different constituents in the whole system that responsible for the improvements in the mechanical properties. The microstructure of the optimum G18 geopolymer mix is well-defined with no or little pores that responsible for the improving of physical properties and the enhancement of mechanical strengths, whereas the microstructure of G24 is more porous and heterogeneous matrix which was contributed to the reduction of mechanical strengths.

Workability, strength, and shrinkage of ultra-high-performance seawater, sea sand concrete with different OPC replacement ratios

An experimental investigation on the chemical, physical, mechanical, and shrinkage of seawater and sea sand-based ultra-high-performance concrete (UHP-SWSSC) with supplementary cementitious materials (SCM) (i.e. slag and silica fume) is reported. Several mixes were designed with varying proportions of SCMs (25%, 37.5%, 50%, and 62.5% of binder), aggregate source, and water-to-binder ratio. Heat evolution, density, workability, compressive strength development, and long-term autogenous and drying shrinkage of UHP-SWSSC were monitored. Seawater accelerates cement hydration as reflected in the heat evolution, and consequently, dictates the early-age strength, and autogenous shrinkage. SCM addition although limits the early-age strength development offers a comparable 90 days strength. The chloride content increases from marine resources and may limit the application to nonstructural components. Nonetheless, a UHP-SWSSC mix with 50% OPC replaced by 37.5% slag and 12.5% silica fume is recommended in this study, which can achieve satisfactory workability, long-term strength, and shrinkage properties.

Partial Replacement of Cement by Waste Paper Pulp Ash and Its Effect on Concrete Properties

An investigation was conducted to study the viability of using waste paper pulp ash as an alternative material applied as a partial replacement of cement in the manufacturing of concrete and its effect on the properties of concrete, and also, the cost and environmental advantage of using waste paper were examined. Four concrete mixes with 0%, 5%, 10%, and 15% waste paper pulp ash replacement of OPC and PPC for 25 MPa concrete were prepared. Based on the results obtained from the research, the highest compressive strength obtained at all test ages, i.e., 3, 7, and 28 days, were, 24.36, 28.35, and 36.83 MPa, respectively, with 5% replacement of waste paper pulp ash for OPC, and for PPC, all percentage replacements showed reduction in compressive strength than the control mix. The water absorption of concrete was increased with increasing the percentage of waste paper pulp ash than control concrete. The control concrete clearly has the lowest resistance to 2% sulfuric acid solution compared to blended concrete of OPC‐WPPA and PPC‐WPPA. The cost comparison indicates that the incorporation of waste paper pulp ash decreases the cost of concrete and WPPA and saves raw materials used in cement and concrete production.

Experimental Investigation on Effect of Partial Replacement of Cement with Bamboo Leaf Ash on Concrete Property

Ethiopia’s construction industry is aggressively expanding than ever before. Cement is the most essential and expensive material in this regard. Cement takes 10%–15% by volume of concrete. Nowadays, the construction industry is challenged by the scarcity of cement and price escalation of the cement market. However, scholars try to replace cement with pozzolanic material. Besides this, they investigated that bamboo leaf ash possesses pozzolanic properties. Ethiopia has about 850,000 hectares of lowland bamboo, so it is good to utilize bamboo leaf ash as a replacement material for cement. In this study, the capability of lowland Ethiopian bamboo leaf ash as a partial substitute for cement in C-25 concrete production with 0%, 5%, 10%, 15%, and 20% replacement of OPC by BLA with 0.49 percent water-to-cement ratio was investigated. This study examines the chemical properties of BLA, physical properties of cement paste, workability, compressive strength, water absorption, density, and sulfate attack of concrete. The chemical composition of bamboo leaf ash was examined, the summation of SiO2, AlO3, and FeO3 is 76.35%, and the ash was classified class N pozzolan. The normal consistency percentage of water increases as the BLA replacement amount increases, and both initial and final setting time ranges increase as the BLA replacement amount increases. The compressive strength of concrete for 5% and 10% BLA achieves the target mean strength (33.5 MPa) on the 28th day, and on the 56th day, 5% and 10% replacements increase the concrete strength by 1.84% and 0.12%, respectively. The water absorption and sulfate attack have significant improvement of the BLA-blended concrete on 5% and 10% BLA content. According to the findings, bamboo leaf ash potentially substitutes cement up to 10%. The outcome of the study will balance the cement price escalation and increase housing affordability without compromise in quality.

A Study on the Strength Aspects of Concrete with Metakaolin, GGBFS and Rice Husk Ash as Partial Replacement of OPC

The impact of the OPC on the environment is important as its production generates a large amount of CO2. In order to reduce the use of pure raw materials as resources, the use of industrial waste or secondary materials in construction sites for the production of cement and concrete has been encouraged. The volume of wastes generated worldwide has increased over the years due to the population, social and economic performance and social development. One of the most attractive options for waste management is to minimize waste and reuse the possibility of recycling. The cost of cement used in concrete works is increasing and unsatisfactory, but the demand for this material and other housing needs is rising, so it is important to find alternatives that can be used alone or in a partial replacement. In this research work several auxiliary cementitious ingredients such as metakaoline, GGBFS and Rice Husk Ash (RHA) were used to improve the strength properties of the conservative concrete. Metakaolin and GGBFS was used at a fixed percentage of 10 percent as fractional substitution of the OPC-43 grade cement, while the RHA was used at different percent ranging from 0 to 25 percent at an increment of 5 percent in each case as fractional substitution of the OPC-43 grade cement. Numerous examinations were executed so as to envisage the effect of these materials over the strength and engineering properties of the concrete. The test results conclude that the usage of the metakaolin, GGBFS and the RHA in combined form increased the strength and engineering properties of the conventional concrete up to a great extent. From the obtained test results it can be further concluded that the particle size of the supplementary cementitious materials plays a significant role in enhancing the internal micro-structure of the concrete and which further leads to the higher strength of the concrete. Also the main reason behind the advanced strength was the presence of the metakaolin and GGBFS in the concrete, whose chemical properties densifies the concrete and made the concrete more stable and promotes higher strength. Future work can also be done on the usage of several other supplementary cementitious materials at different other percentages so as to improve concrete properties.

To Determine the Strength Development of Concrete Made from Ground Granulated Blast-Furnace Slag as a Partial Replacement for OPC in Cement Concrete

Abstract: Concrete is the most widely used construction material on the planet, with around six billion tonnes manufactured each year. In terms of per-capita usage, it is only second to water. However, both the damage caused by raw material exploitation and CO2 emissions during cement manufacturing harm the environment's long-term viability. This put pressure on researchers to find ways to reduce cement use by partially substituting additional materials for cement. These materials could be naturally occurring, industrial leftovers, or less energy-intensive byproducts. When these components (known as pozzalonas) are mixed with calcium hydroxide, they produce cement. Fly ash, silica fume, metakaolin, and crushed granulated blast furnace slag are the most regularly utilised pozzalonas (GGBS). It is necessary to investigate the performance of admixtures when mixed with concrete in order to provide a lower life cycle cost. The purpose of this work is to investigate the characteristics of M20 grade concrete with partial substitution of cement with ground granulated blast furnace slag (GGBS) at percentages of 10%, 20%, 30%, 40%, and 50%. Keyword: Pozzolans, hardened mortars, thermal shrinkage, Increase the water tightness, Improve workability and Lower costs

Reactivity in cement pastes bearing fine fraction concrete and glass from construction and demolition waste: Microstructural analysis of viability

Converting construction and demolition waste (CDW) into secondary raw materials is one of the priorities of environmental policy and circular economy strategy. This study analysed the variation in eco-efficient paste reactivity with OPC replacement ratio (5% to 10%) and hydration time (2 d, 28 d and 90 d). Three types of CDW were explored: two (calcareous and siliceous) consisting of fine (<5 mm) concrete waste and one in laminated glass (<40 mm). Further to the mineralogical phases identified at the aforementioned percentages, the four materials, i.e., the three types of CDW-blended cements and the OPC reference, were similarly reactive. The primary hydration products, C-S-H gels, C4AH13 and C4AcH11, ettringite and portlandite, were the same as observed in OPC hydration. These findings attest to the scientific viability recycling such CDWs as mineral additions in eco-cement manufacture and consequently eliminating the need for stockpiling these materials at recycling/storage plants.

Modification of concrete mortar using polyurethane resin

This paper presents an experimental investigation carried out to study the effects of non-water soluble Polyurethane Resin used in the modification of concrete mortar. The non-water soluble Polyurethane Resin (PU) was obtained from Fursa Industry and Tech Limited. The non-water soluble PU was used for this study do to its availability and low cost. Additives such as; Sulphur and Calcium Oxide responsible for binding and curing were used. Concrete mortar cubes of 50 x 50 x 50 mm respectively were produced with grade 42.5 Ordinary Portland Cement from Dangote Cement Limited. The ordinary Portland Cement was partially replaced with 0% (control), 15%, 25% and 35% non-water soluble Polyurethane Resin respectively. The influence of partial replacing Ordinary Portland Cement with non-water soluble Polyurethane was checked by testing the concrete mortar cubes for compressive strength testat7, 14 and 28 days respectively after casting and curing. It was observed that the addition of Polyurethane Resin as OPC partial replacement leads to considerable increase in compressive strength at 25% and 35% in comparison to the compressive strength of the control sample. The improvement in compressive strength was not significant beyond 35% Polyurethane replacement of OPC and was there accepted as the optimum percentage replacement.

Replacement of OPC by Zirconium Nano Particle in Concrete

It has been shown nanoparticles can act as heterogeneous nuclei for cement pastes, further accelerating cement hydration because of their high reactivity. As a nano-filler, it densifying the microstructure, thereby, leading to a reduced porosity. Because of ultrafine size, nanoparticles show unique physical and chemical properties different from those of the conventional materials. Because of their unique properties, nanoparticles have gained good attention in construction fields. In this study, 1% cement was placed with ZrO2 nanoparticle of 33 nm to improve the mechanical (compression strength and split tensile strength), durability (Rapid chloride permeability and carbonation test) and microstructural (FESEM) properties in concrete structures and results are compared with normal concrete.

Optimization of Bentocrete parameters using Response Surface Methodology (RSM)

<abstract> The present study aims at the influence of water/cement (W/C) ratio on workability, compressive strength, and durability, and microstructure of concrete by partial replacement of cement with bentonite (Bentocrete). The model development with the help of the matrix design was carried out using Response Surface Methodology (RSM). Scanning Electron Microscope (SEM) and X-ray diffraction used for assessment of bentonite microstructure. The variables in this research were water/cement (W/C) ratio and percentage of bentonite replacement. The W/C ratio was varied between 0.60 and 0.70; 0%, 10%, 20% and 30% of cement were substituted with bentonite. The responses (slump value, compaction factor, compressive strength (28 d), split tensile strength, flexural strength and charge passed through concrete (28 d) were assayed for all mixes. Design Expert 11.0 version was utilized for optimization using RSM. Bentonite's high-water absorption capacity decreased the workability as the OPC percentage decreased in the Bentocrete. The result has shown that the compressive strength, split tensile strength, and flexural strength of Bentocrete has decreased to 80% replacement of bentonite with OPC, increasing beyond that. This decrease is due to bentonite's pozzolanic reactivity. The durability of Bentocrete improved up to 20% replacement of OPC with bentonite. The increase is might be due to the pore filling effect, bentonite particles occupy the voids created by OPC since the particles of bentonite were finer than OPC. The models generated from RSM are valid with statistical significance in all the factors considered. 9.91% of the cost can be cut down at 80% cement substitution. The optimum solution with a desirability of 0.881 was obtained with 3.92% of bentonite substitution and 0.62 W/C ratio. The intended Bentocrete can be utilized in low-cost concrete production. </abstract>

Effect of Temperature on mechanical properties of Geopolymer concrete: A Review

Concrete is the most widely used material after water in building and construction field. It is the oldest man-made material and is easily available for use at cheaper costs. This material is causing harm to environment on mass extent. OPC i.e. Ordinary Portland Cement is second contributor after automobile industry in Carbon Dioxide emission. This review presents the study of replacement of regular concrete cement with cementitious material like fly ash, silica fumes, GGBS etc.. Geopolymer Concrete is innovative solution and is result of the chemical action of inorganic molecules. Fly ash is widely available as by product of many Coal industries. Use if this by product will reduce the cost of the concrete plus reduce the waste of byproduct of coal industries. This will contribute majorly in reducing carbon footprint and will work in favor of betterment of environment. This survey emphasizes on replacement of regular OPC with Geopolymer concrete. Keywords: OPC-Ordinary Portland Cement, Fly ash, Activation material, geopolymer concrete.

Alkali-reduced Bauxite Residue as Novel SCM

Abstract Bauxite residue is a major waste stream available in large volumes globally that can cause risks to the surrounding environment (e.g. ecotoxicity) when disposed and stored by conventional methods. There is yet no large-scale application and the utilization as supplementary cementitious material might be the best way to re-use bauxite residue. The main obstacle for the utilization of bauxite residue in the construction industry is the high alkalinity. This paper presents first results of a study on alkali reduction of bauxite residue by acetic acid treatment and the potential application of this alkali reduced bauxite residue as pozzolan in cementitious binders. A process of alkali reduction is presented that can help solving waste management problems of alumina refineries by transforming bauxite residue to a less hazardous waste, while producing a reactive pozzolan and Na-acetate that can find application in the construction and infrastructure market. 90% alkalinity reduction of bauxite residue could be achieved by simply washing with diluted acetic acid. Alkali-reduced bauxite residue showed good pozzolanic reactivity regarding portlandite consumption, bound water and 28-day compressive strength of mortars with 20% replacement of OPC.

Physicochemical analysis of sugarcane bagasseash (SBA) blended concrete to evaluate the pozzolanic activity of SBA

Sugarcane bagasse ash (SBA) is the residue of burnt sugarcane bagasse used as a fuel in the co-generation units. The enormous quantities of SBA obtained as waste material from the cogeneration units can be utilized as a pozzolona.This article presents the investigation on the physical and chemical analysis on concrete made with OPC blended with SBA. Experimental investigation is performed on M30 grade concrete which forms the control mix. SBA blended concrete is obtained by partially replacing the OPC with SBA at different percentages. The workability of the fresh concrete and compressive strength at 7 and 28 days of the control concrete and SBA blended concrete are determined.The particle size distribution, surface area and specific gravity of OPC and SBA were determined using HORIBA zeta analyzer, BET surface area analyzer and Standard Le-chatelier flask respectively. The chemical composition of SBA and OPC was obtained using XRF technique and the mineralogical analysis of SBA was carried out using XRD technique.To evaluate the pozzolanic activity of SBA, the hardened concrete matrix wereanalyzed for their microstructural and chemical composition using SEM and EDS techniques. The compressive strength results indicate that replacement of OPC by SBA upto 20% is beneficial. The SEM images and EDS analysis substantiates the pozzolanicbehavior of SBA at different replacement percentages.

Study of HSC by Using Fly Ash as Partial Replacement of Cement & Incorporating of Steel Fibers

Concrete is one in all the foremost common building materials used. The current study deals with high strength concrete by adding steel (metallic) fiber material in different volume fractions 0%, 0.3%, 0.6%, 0.9%, 1.2% and 1.5% to strengthen the engineering concrete properties and partial replacement of OPC with fly ash in percentages of 0-25% in various ratios. The specimen’s exposure periods of 7, 28 and 56 days on numerous tests like compressive, flexural and split tensile strengths. The research has focused on mechanical and durability properties of high strength concrete. It was observed that 20% fly ash replacement produces the max compressive strength parameters with 1.2% crimped steel fibers, but, the split tensile and flexural strength of concrete was maximum at 25% fly ash along with 1.5% steel fibers. Furthermore, the durability of concrete has conducted such as acid attack due to HCl and H2SO4. The minimum loss of weight produces at the 25% fly ash is 2.98% and 2.81% by HCl and H2SO4.

Effect of potassium hydroxide and lime on the strength and durability of cassava peel ash blended cement mortar

ABSTRACT This research work investigates the effect of addition of potassium hydroxide (KOH), an alkali, and lime on the properties of cassava peel ash (CPA) blended cement mortar. Four binder combinations were used, viz; ordinary Portland cement (OPC, control), OPC-CPA blend, OPC-CPA-Lime blend and OPC-CPA-Lime-KOH blend respectively at 10% replacement of OPC with CPA. Properties investigated include strength and durability, measured using sorptivity, water absorption and apparent porosity for mortar specimen cured at 7, 14 and 28 days respectively for each of the binder combinations. The result shows that the OPC-CPA-Lime mortars showed better compressive strength, sorptivity, apparent porosity and water absorption performance than the other mixes. The performance of CPA-Lime blended cement mortar at 10% replacement of OPC with CPA and 4% replacement of CPA with lime compared favorably with OPC mortars in terms of strength and durability and is thus recommended for use in mortars.

A study on incorporation of supplementary cementitious materials for sustainable development

In concrete world cement is the main ingredient. The manufacture of cement leads many issues in the environmental safety. So we are in need of replacement against cement as a binder in concrete. There are many alternatives availability for the replacement of cement. Here in our study we use eggshell powder, rice husk ash and sawdust ash as partial replacement of OPC. The mix designated for the study is M25 grade. The replaced eggshell powder & rice husk ash each as 10, 20 and 30 percentage respectively with the weight of cement. Sawdust added as a admixture to improve the properties of concrete. The saw dust added upto 2.5% of binder as additive. The investigation of compressive strength, flexural strength and split tensile strength results at 7 & 28 days were obtained. The research found, the use of eggshell, rice husk ash and sawdust ash improves the structural properties of concrete compared to the conventional concrete.