Substitution Of Cement Research Articles

Carbon Emissions Assessment Fly ash and Steel Slag As a Substitute for Cement in Concrete Mixing Using the Method Artificial Neural Networks

Concrete is a construction material made from a mixture of Portland cement, air, coarse aggregate, fine aggregate, and sometimes also uses admixture materials with a certain ratio. Cement, which is the binding agent in the concrete mixture, contributes to 8% of the world's carbon dioxide (CO2) emissions. Fly ash and steel slag are one of the wastes that are currently being researched and developed as cement ingredients in concrete mixtures. This is because the chemical composition of fly ash and slag associated with cement is very suitable when added to concrete mixtures.This study aims to find out of the optimal of fly ash and slag content in the concrete mixture in terms of strength by using the Artificial Neural Network (ANN) method and in accordance with SNI 7656: 2012. Furthermore, this study also aims to measure the ratio of CO2 emissions that are produced from normal concrete, concrete with fly ash, and concrete with steel slag, using references from Idemat2014 and Ecoinvent V3.The results showed that the optimum content of fly ash class F, fly ash class C, and steel slag in the concrete mixture were 30%, 20%, and 55%, respectively. The results also concluded that steel concrete slag as the lowest emitter of CO2 compared to normal concrete, class F fly ash concrete, and class C fly ash concrete. Keywords: concrete, fly ash, steel slag, ANN, comppresive strength, CO2 emission

Fly ash, GGBS, and silica fume based geopolymer concrete with recycled aggregates: Properties and environmental impacts

Recycled coarse aggregates (RA) are sustainable alternatives to natural aggregate (NA) in concrete; however, their mechanical performance has not been competent to the later. The partial replacement of Ordinary Portland Cement (OPC) with the use of industrial by-products for preparation of geopolymer concrete (GPC) has also harnessed great research interest. The objective of the current study is to investigate the technoenvironmental feasibility of using fly ash (FA), ground granulated blast furnace slag (GGBS), and silica fume (SF) in GPC to support the use of 100 % RAs in concrete. This study aims to optimize the proportion of GGBS, FA, and SF in the design mix for the best mechanical performance and eco-efficiency of GPC concrete as compared to conventional OPC concrete. Results indicated positive synergistic effect between FA, GGBS, and SF causing improved mechanical, and microstructural performance of RA based GPCs as compared to OPC concrete with RA. The highest compressive (52.15 MPa), flexural (5.81 MPa), and split tensile strength (5.23 MPa) were exhibited by GPC-MG15 with a cement substitution ratio of FA: GGBS: SF – 35:50:15 which were 18–34 % and 7–10 % higher than that of OPC concrete with NA and RA, compensating the effects of RA addition. The microstructural, and mineralogical properties analysed through SEM and XRD results depicted the densification of the matrix and formation of C-S-H, C-A-S-H, and N-A-S-H gels which could be the possible reasons for the improved performance of GPCs. The environmental performance of optimized GPCs analysed through Life cycle assessment (LCA) reported a 50–60 % reduction in the environmental impacts as compared to OPC concrete with NA. Although GPC-FG50 (GGBS: FA – 50:50) was also environmentally competent, GPC-MG15 was the most sustainable concrete mix which was environmentally superior while not compromising on the functional properties.

Self-compacting concrete incorporating incinerated biomedical waste ash: a performance assessment

Rapid technological advancement is underway in the sphere of material science research. Several studies have been undertaken around the globe over the last four decades to improve the strength and durability performance of concrete. As a result of ongoing research and experimentation, concrete no longer just consists of the traditional materials of cement, aggregates and water but has transformed into an engineered custom material with efficient new ingredients in order to meet the demands of the expanding construction industry. In this experimental study, biomedical waste incinerator ash (BMIA) was employed as a partial substitute for cement in self-compacting concrete (SCC), designed for M30 grade. BMIA was partially replaced with cement in proportions of 0%, 5%, 10%, 15% and 20% by cement weight. This experimental work aimed to study the fresh, mechanical and durability characteristics of the SCC mixes incorporating BMIA. A suitable super-plasticizer was used to retain the rheological qualities of fresh concrete. To investigate the mechanical and durability characteristics, experiments on hardened concrete were performed. The results demonstrate that 5% of BMIA substitution for cement in the SCC mix had higher strength compared to all other mixes because BMIA’s fine particles filled the voids in the hardened concrete. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) analyses were performed to examine the microstructure of BMIA substituted SCC versus conventional SCC mix. The chemical composition test revealed that BMIA can be employed in the SCC mix up to 5% efficiently, which will result in waste utilisation and disposal.

The effect of using glass powder as cement substitution and its mixing method on the concrete characteristics

The effect of using glass powder as cement substitution and its mixing method on the concrete characteristics

Feasibility of Using Recycled Construction and Demolition Materials for Deep Soil Mixing

Reusing construction and demolition wastes for geotechnical and geo-environmental purposes has already become a research hotspot. This study was carried out to evaluate the feasibility of using recycled construction and demolition wastes in a partial substitution of cement to enhance the mechanical properties of soft soil. The strength and stiffness development of two types of recycled material (RM1 and RM2), incorporated with peat and clayey soil under 7, 14, and 28 days’ curing time, was investigated based on unconfined compressive strength and free–free resonance frequency test methods. The findings demonstrated that clayey soil showed an average of 2.5 times higher strength than peat with the addition of recycled materials, regardless of the type. However, after 14 days of curing, the strength remained constant for peat soil. Moreover, it is concluded that the studied granular recycled materials could be used to replace a part of the cement content to improve the strength and stiffness properties.

Effect of mechanochemical activation on hydration properties of lead-zinc sulfide tailings for concrete construction

Proper management of mine tailings containing high amount of sulfide is a crucial issue in order to reduce their environmental hazards including generation of acid mine drainage and release of heavy metals. This study was conducted targeting to understand the effects of using lead-zinc sulfide tailings (LZSTs) as cement substitution on the hydration properties of concrete samples. Mechanochemical activation of the LZSTs containing 19.9% sulfide content in mixtures of 20%, 40%, 60%, 80% and 100% was performed to cement-replacement in concrete production. Analyzes were performed on the produced concrete samples. X-ray diffraction, compressive strength, toxicity characteristic leaching procedure (TCLP), mercury intrusion porosimetry, X-ray spectroscopy, scanning electron microscopy, energy-dispersive fourier-transform infrared spectroscopy, thermogravimetric analysis and differential thermal analysis were performed on the constructed concrete samples. The results of XRD analysis confirmed that introduction of activated tailings in the concrete construction led to form hatrurite (Ca3SiO5) phase. According to the TCLP, with increseasing curing days, leached amount of studied toxic metals decreased and was lower than the allowable limit. The results of the mercury intrusion porosimetry (MIP) indicated that as the curing time prolonged, the critical pore size was reduced from 150 to 50 nm in the constructed sample containing 20% activated tailings. Therefore, by activating the tailings, the specific surface area was enlarged and more cohesion took place in the concrete samples. The compressive strength results indicated that the compressive strength after 90 curing days in the constructed sample containing 20% activated tailings was 40.85 MPa, while it was 38.15 MPa in the control sample. In general, the results indicated that the mechanochemical activated of LZSTs with calcium carbonate can be a suitable alternative for cement (up to 40%) in the production of concrete samples.

Life Cycle Assessment of Concrete Using Copper Slag as a Partial Cement Substitute in Reinforced Concrete Buildings

Cement, one of the main components of concrete, poses environmental risks, accounting for 7% of total global carbon emissions. To alleviate the environmental hazards related to cement manufacturing, supplementary cementitious materials (SCM) are employed to reduce the usage of cement in concrete. One SCM used is copper slag (CS). In this study, a life cycle assessment (LCA) is conducted by investigating the environmental impacts of concrete replacing different percentage of cement with CS. As a case study, the LCA was performed for low-rise and mid-rise structures designed with varying concrete strengths, and a cost analysis was performed for these structures when replacing different percentages of cement with CS. Based on the results, the usage of CS was established as being beneficial to the impact categories ADP (Abiotic Depletion Potential (Fossil)) and GWP (Global Warming Potential), but exerted damaging effects on ADP (Abiotic Depletion Potential) and HTP (Human Toxicity Potential). On the basis of the cost analysis, the use of CS as a partial cement replacement was found to reduce building costs by a maximum of 1.4%, which is statistically significant. When evaluating the risk in comparison to the benefit of using CS in buildings, it was found that the negative environmental influence outweighed the favorable influence and cost savings resulting from the use of CS as a cement alternative. However, when only considering GWP, which is the standard procedure for environmental assessment in buildings, the use of CS as a partial cement substitute in buildings was regarded as being beneficial, yielding a 12.80% reduction in carbon emissions.

Experimental investigation of paver blocks using hammam ash

Concrete paver blocks are broadly utilized as a result of their aesthetical appearance and interlocking property.Due to utilization of Portland cement in concrete paver blocks, environmental contamination has gathered. Thus, to limit the utilization of natural resources, different waste materials have been utilized. In this paper, cement has been replaced with Hammam ash.Hammam ash is a residue of Kashmiri poplar tree known as “fras” in local language. With the assistance of XRD test, it is seen that Hammam ash contains cementation properties, thus can be utilized as a substitution of cement in research works. The tests directed for research work are compression and flexural.After the testing and contrasting with standard conventional paver blocks, it has been calculated that the paver blocks with hammam ash accomplishes more compressive and flexural strength. Thus it tends to be utilized as a substitution of cement which decreases the carbon impressions and helps in the usage of waste material.

Investigational studies on the impact of Supplementary Cementitious Materials (SCM) for identifying the strength and durability characteristics in self curing concrete

For optimal heat of hydration and high strength, conventional concrete requires optimum curing and moisture levels for a minimal of 28 days. The durability and strength may decline if the curing is inadequate. Self-curing concrete (SCC) is a specific type of concrete that reduces inadequate curing resulting from human error. Water scarcity in arid regions, difficulty in accessing buildings in challenging terrain, and locations where the concentration of fluorides in the water may adversely impact the concrete's mechanical properties. Developing concrete using Supplementary Cement Materials (SCM's) that have pozzolanic qualities in nature as well as self-curing additives would be seen as a prospective enterprise for meeting sustainability commitments. Industrial wastes like as Silica Fume (SF), Ground granulated blast furnace slag (GGBFS), Fly Ash (FA) and Alccofine (AF) are used as SCM. Polyethylene Glycol (PEG) is an instance of a self-curing compound. Throughout the study, FA and SF will be used as cement substitutions, and Polyethylene Glycol (PEG 400) will be used as a self-curing agent, with just a focus on quantifying the influence mostly on hardened qualities of concrete. To test the qualities of concrete, different ratios of cement were substituted for the cement with varying percentages of SF at 5%, 10% and 15% and FA at 30%, 25%, 20%. Different dosages of PEG varying from 0%, 0.1%, 0.5% and 1.0% are used to understand the optimal dosage of self-curing agent.

The Strength, Microstructure, and ecological assessment of concrete mix incorporating waste glass powder and polypropylene fiber

Using waste glass powder (WGP) as a source of silica in the production of cement-based materials could form denser matrix and address the ecological challenge of its deposition. This study introduces two grades of fineness of WGP: fine glass powder (FGP) and ultrafine glass powder (UFG) as 5 % and 10 % substitution for cement in the production of concrete reinforced by polypropylene (PP) fiber. Nine concrete mixes are investigated for their mechanical and ecological performances. Additionally, the study of mixes’ microstructure is reported to observe the influence of WGP and PP fibers contributions on the hardened matrix. ‌Based upon the results, FGP incorporation significantly enhances the FRC compressive strength from 7 to 90 days (between 40 % and 60 %). However, the highest mechanical performance is achieved by 10 % UFG as cement replacement and 0.5 % PP fiber inclusion. Moreover, scanning electron microscope (SEM) results show more chemical activity of UFG, and less calcium hydroxide presented in the hardened matrix. In terms of ecological concerns, between 5 % and 10 % lower CO2 and SO2 emissions and water usage indices for proposed concrete mixes containing WGP, and PP fiber are obtained, while the required energy consumption for preparing these mixes significantly increases (around 15–45 %) due to UFG and PP fiber incorporation in FRC.

Addition of Fly Ash and Aluminum Slag as Cement Substitute Materials to Cellular Lightweight Concrete

Most of the construction buildings that are often found use concrete as the main building material. The development of technology makes more and more new types of modified concrete, one of which is lightweight concrete. Lightweight concrete that is often found is lightweight concrete CLC (Cellular Lightweight Concrete). The construction of non-structural elements of the building applies CLC lightweight concrete at a lower cost than standard concrete due to faster work, more temperature resistance, ease of handling, and lighter density. This study aims to find the optimum percentage and effect of using aluminum slag and fly ash as a partial replacement of cement in cellular lightweight concrete. The test object is printed in a molding size of 5x5x5 cm3. The use of aluminum slag is 0%, 1.5%, 3%, 4.5%, 6%, and 7.5%, while the use of fly ash is 15% of the cement weight. The tests carried out included volume weight, compressive strength, and water absorption at the age of 3, 7, 14, 21, and 28 days. The results of this study, it can be concluded that increasing the variation of aluminum slag with fly ash content remains at 15% in each variation as a cement substitution, the most significant variation is 1.5%. The optimum compressive strength test results at a variation of 1.5% of 4.1 MPa with the highest specific gravity of 752 gr/cm3, and water absorption of 66.67%, it all specimens at the age of 28 days.

Cement Kiln Dust (CKD) as a Partial Substitute for Cement in Pozzolanic Concrete Blocks

This study investigates the effect of the partial replacement of ordinary Portland cement (OPC) with cement kiln dust (CKD) on the engineering properties of pozzolanic concrete for use in block manufacturing. Ultimately, this could potentially reduce cement consumption and CO2 emissions. The study was carried out on cylindrical concrete samples prepared from five mixtures comprising 71.13% pozzolan and 14.16% water, with 0, 5, 10, 15, or 20% of the OPC fraction (14.71 wt.%) replaced by CKD. The samples were tested for density and compressive strength (UCS) at curing ages of 7, 14, 28, 56, and 91 days; and for voids and water absorption after 28 curing days. Results show that increasing CKD content lowered the voids and increased the water absorption. The 15% CKD sample had the highest UCS, regardless of the curing age. X-ray diffraction analysis confirmed that the phase responsible for hydration, calcium silicate hydrate, was higher in the 15% CKD sample than the control.

Mechanical and Microstructural Studies of High Performance Concrete with Condensed Silica Fume

This article is an extended version of the conference paper “Influence of silica fume on mechanical and fracture properties of high performance concrete” published in Procedia Structural Integrity as a part of the Special Issue for the 3rd International Conference on Structural Integrity (ICSI 2019). Tests were carried out to evaluate the compressive strength, tensile splitting strength, modulus of elasticity, flexural strength, and fracture properties of high performance concretes (HPC) having different levels of condensed silica fume (CSF) replacements for cement. It was found that CSF replacement for cement by up to 25% may have a favorable effect on the mechanical properties. HPC containing CSF was characterized by quite large increases in compressive strength (up to 14%) and flexural strength (16%). However, the most significant improvements in mechanical properties were obtained for splitting tensile strength (26%) and fracture energy (30.5%). There were slight reductions up to 2% in the elastic modulus, flexural strength and fracture properties at the 25% level of CSF substitution for cement. Microstructural studies showed that the narrowest microcracks and the smallest pores in the interfacial transition zone (ITZ) between the paste and grains of aggregate occurred in the HPC having 10% CSF. In addition, a reduction of ITZ around the aggregate and the formation of more high-strength hydration products was observed in all CSF-added HPCs. The outcomes reported that CSF can successfully replace cement. It is suggested that the substitution should not exceed 20%.

Investigating the ternary cement containing Portland cement, ceramic waste powder, and limestone

The cement production process produces enormous amounts of carbon dioxide (CO2). Hence, using new types of cement, like ternary cement, which contains calcined clay, limestone, and cement clinker, can significantly reduce the CO2 emissions of the cement industry and even increase the mechanical properties and durability of samples. This paper investigates the cement mortar's mechanical and durability characteristics, containing ceramic waste powder (CWP) and limestone powder (LSP) as partial cement substitution. Samples with 5, 10, and 15 % LSP and 10, 20, and 30 % (by weight of cement) CWP as cement substitutes were produced. The mortar specimen tests were performed after 7, 28, and 90 days of curing in the water pool, then compressive strength and alkali-silica reaction (ASR) tests were evaluated. Furthermore, setting time test, thermogravimetric analyses, X-ray diffraction analyses, and scanning electron microscopy (SEM) of cement paste were carried out. The ternary cement mortar containing 10 % CWP and 15 % LSP has the highest compressive strength. Also, the ternary cement mortar containing 30 % CWP and 15 % LSP shows the lowest compressive strength (decreased by 8.5 % compared to the reference sample). In addition, the mix containing 20 % CWP and 15 % LSP has a lower ASR value than the control sample (52 % less). Eventually, SEM images showed the reference sample and the specimen containing 30 % CWP and 15 % LSP have the lowest and highest pores and cavities, respectively.

Properties of pervious concrete incorporating fly ash as partial replacement of cement: A review

Disposing fly ash in to landfill of coal fire power plant initiated environmental and health problems. A lot of researchers have conducted research to study the addition of fly ash (FA) as cement replacement in pervious concrete (PC). The aim of this paper was to review the impact of adding FA as partial substitution of cement in PC. The experimental outcomes from different previous studies have indicated that the void content and permeability of PC decreased with adding FA due to filler effect of FA. The optimum substitution level of cement with FA was obtained to be 10–30%. However, with increasing the level of replacement affects the hydration procedure resulting lower strength. PC containing FA showed higher abrasion resistance and lower drying shrinkage compared to normal PC. It can be concluded that using FA as partial substitution of cement would be environmentally friendly in association with more sustainable PC.

Hydration kinetics and microstructure development of Ultra-High Performance Concrete (UHPC) by high volume of phosphorus slag powder

In this paper, the effect of phosphorus slag(PS)hydration kinetics and microstructural development of UHPC with different degree of substitute (20%, 40% and 60% by mass) were explored. Up to 60% substitution of cement by PS which still shown excellent mechanical property compared to without PS at the age of 60-days. The phase development is a qualitative discussion by thermal gravimetric analysis combined with XRD with Rietveld method, the pore structure is evaluated to MIP. The hydration products are characterized by SEM (scanning electron microscopy) with EDS (Energy-dispersive X-ray) analyses. The results shown that the utilization rate of cement has been significantly improved, for instance, the hydration rate of the cement is enhanced from 54.3% for PS0 to 87.0% for the UHPC with PS60; the Ca/Si ratio decreased with the enhance of PS content and the microstructure is become denser by SEM-EDS tests. The pozzolanic-reaction of PS cloud produce more hydrated products by thermodynamic calculation, which can optimize the pore structure of paste. And the growth trend of C–S–H gel is consistent with the compressive strength growth trend.

The durability performance of waste cardboard kraft fibre reinforced concrete

Despite the high recycling rate of cardboard, a significant amount of this material is disposed of in landfill areas. The conversion of cardboard waste into kraft fibres (KFs) offers potential sustainability benefits when used in the building and construction industry. This study comprehensively analyses the durability of KF reinforced concrete as a partial cement substitution. Durability testing was conducted, exploring the composites microstructure when integrating KFs derived from waste cardboard. Fibre and matrix modification techniques were utilised via silica fume (SF) and metakaolin (MK), respectively. Porosity analysis of the novel composites demonstrated connecting microstructural system, enhancing the knowledge of durable aspects of potential service life of the composites. SF reduced the water permeability of the novel composites as demonstrated via water absorption and immersion testing. At one year, there was a reduction of chloride ion transference for all fibre composites. Composites were aged via wet and dry cycles, then tested for their compressive and tensile strength at each interval. Compressive strength of all samples peaked at 60- 80 day-cycles. Fibre Matrix modified composites demonstrated a tensile strength of 2.5 MPa when subjected to 100 day-cycles, with the control having 2.7 MPa.

Minimizing the impact of microorganism intrusion on the concrete physical and mechanical properties with nickel waste as a partial substitution for cement

This study examined the impact of microorganism intrusion on concrete's physical and mechanical properties and efforts to minimize the effect by using nickel waste as a partial substitute for cement. The microorganisms resulted from the natural fermentation of coconut water which intruded into the concrete material, harming the concrete's physical and mechanical properties. Physical and mechanical properties observed were porosity, permeability, and compressive strength. The results indicated that the intrusion of microorganisms into the concrete material increased porosity and permeability and decreased the compressive strength of the concrete. Using nickel slag as a partial cement substitution material with an optimal percentage of 15% was employed to overcome these impacts.

Effect of PET Resin as Cement Substitute on Properties of Cement Mortar Subjected to Different During Conditions

Polyethylene terephthalate (PET) has many advantageous properties required for the packaging industry. However, the safe disposal of PET waste is an environmental challenge. The present study investigates the feasibility of using PET resin prepared through glycolysis in polypropylene glycol (20:80 and 30:70 PET-to-glycol ratios) as a replacement for cement (5%, 10%, and 15%) in cement mortar. The effect of PET resin with melamine-formaldehyde as a hardener replacement on the consistency, setting time, soundness, compressive strength, tensile strength, and abrasion resistance was experimentally studied at two different curing conditions viz. under water curing and oven-dry curing. Findings of the present investigation infer that the compressive, tensile strength, and abrasion resistance improves upon oven-dry curing. The study concludes that the use of PET resins improves the attributes of cement mortar and at the same time provides an environmentally friendly way to dispose of the PET waste.

Insight into the Behavior of Mortars Containing Glass Powder: An Artificial Neural Network Analysis Approach to Classify the Hydration Modes.

In this paper, an artificial neural network (ANN) model is proposed to predict the hydration process of a new alternative binder. This model overcomes the lack of input parameters of physical models, providing a realistic explanation with few inputs and fast calculations. Indeed, four mortars are studied based on ordinary Portland cement (CEM I), cement with limited environmental impact (CEM III), and glass powder (GP) as the cement substitution. These mortars are named CEM I + GP and CEM III + GP. The properties of the mortars are characterized, and their life cycle assessment (LCA) is established. Indeed, a decrease in porosity is observed at 90 days by 4.6%, 2.5%, 12.4%, and 7.9% compared to those of 3 days for CEMI, CEMIII, CEMI + GP, and CEMIII + GP, respectively. In addition, the use of GP allows for reducing the mechanical strength in the short term. At 90 days, CEMI + GP and CEMIII + GP present a decrease of about 28% and 57% in compressive strength compared to CEMI and CEMIII, respectively. Nevertheless, strength does not cease increasing with the curing time, due to the continuous pozzolanic reactions between Ca(OH)2 and silica contained in GP and slag present in CEMIII as demonstrated by the thermo-gravimetrical (TG) analysis. To summarize, CEMIII mortar provides similar performance compared to mortar with CEMI + GP in the long term. This can later be used in the construction sector and particularly in prefabricated structural elements. Moreover, the ANN model used to predict the heat of hydration provides a similar result compared to the experiment, with a resulting R² of 0.997, 0.968, 0.968, and 0.921 for CEMI, CEMIII, CEMI + GP, and CEMIII + GP, respectively, and allows for identifying the different hydration modes of the investigated mortars. The proposed ANN model will allow cement manufacturers to quickly identify the different hydration modes of new binders by using only the heat of hydration test as an input parameter.