Cement Replacement Research Articles

Whole‐Life Embodied Carbon Reduction Strategies in UK Buildings: A Comprehensive Analysis

ABSTRACTThis paper presents a detailed analysis of embodied carbon (EC) in various case studies using life cycle assessment (LCA) methodology. Through comprehensive assessments, including modules A, B and C, the study evaluates EC across different stages of building life cycles. This study also considers the EC savings achievable through current end‐of‐life strategies in the UK context. As Module A accounts for the highest EC in the case studies, the majority of reduction strategies should focus on this stage. The most impactful strategy for reducing EC emissions involves incorporating Ground Granulated Blast Furnace Slag (GGBS) as a replacement for cement. This approach has the potential to achieve a substantial reduction in the EC of concrete within the buildings under investigation, ranging from 60% to 70%. The study reveals that specification strategy can lead to significant Whole Life Embodied Carbon (WLEC) reductions, with the residential building achieving a 30.59% reduction, the college building a 46.86% reduction, and the hotel building a reduction of 23.69%. Effective mitigation strategies, such as utilizing recycled and reclaimed materials, demonstrate promising results, showcasing significant reduction in WLEC emissions in the buildings.

Assessment of waste eggshell powder as a limestone alternative in portland cement

AbstractThe decarbonization of the concrete industry is an ongoing pursuit. One solution towards this goal is the use of limestone powder in portland cement. Waste eggshell has tremendous potential as an alternative calcite filler in cement due to its similarities with limestone. In this research, the feasibility of adding 15% and 35% ground eggshell in portland cement to make cement mortars was investigated. The hydration mechanism of eggshell and limestone blended cements was compared through the heat of hydration, phase assemblage, electrical resistivity, compressive strength, and shrinkage measurements. The experimental results showed that cement mortars with ground eggshell attained similar compressive strength as that with limestone. However, eggshell mixtures demand more mixing water to compensate the hydrophobicity of the eggshell membrane. The high calcite content in both eggshell and limestone accelerates the hydration of cement at 15% replacement, but ground eggshell retards cement hydration at 35% replacement due to the dominant influence of the membrane. Overall, eggshell waste is a feasible sustainable alternative to limestone powder at up to 15% portland cement replacement levels. Lifecycle assessment and cost analysis showed that adding 15% ground eggshell in cement concrete further reduces its embodied carbon and energy and cost compared to cement concrete containing limestone powder.

Experimental Study of Sugarcane Bagasse Ash as Partial Replacement of Cement Based on SEM and XRF Analysis

This research aims to identify chemical composition and it’s leaching from concrete mixed with sugarcane bagasse ash. By manipulating percent of slump flow at 110±5%, sugarcane bagasse ash was employed as a pozzolanic material to partially replace cement at 0, 10, 20, 30, 40, and 50 percent by weight of binder in concrete. Cube specimens were cast and cured in water for 3, 7, 14 and, 28 days, respectively. The patterns of sugarcane bagasse ash morphology were performed by using Scanning Electron Microscope (SEM) to analyze physicochemical characteristics. Results of tests on the X-ray fluorescence (XRF) analysis from the ash and curing water at various times revealed that SiO2 made up half of the components in sugarcane bagasse ash. Al2O3, CaO, Fe2O3, K2O, P2O5, and MgO were the minor components. The calcium content from the 14-day period at 50% by weight of the sugarcane bagasse ash binder was higher than that of the other elements, according to the results of curing water. According to the results of 28-day water curing, potassium outnumbered all other elements in the replacement of sugarcane bagasse ash in every ratio.

Performance of Molasses Waste as a Cement Replacement to Study Concrete Compressive Strength

To reduce the negative environmental impact of cement production and preserve natural resources, an experimental investigation was conducted to study the performance of concrete specimens at different curing ages and to determine the compressive strength of these specimens by replacing cement with molasses. Experimentation was carried out on the concrete specimens at a temperature range of 25 °C to 30 °C; six specimens were cast for each replacement ratio, except for 0.75% wt. of cement (86.55 g) and 1% wt. of cement (113.6 g), where five samples were considered for each ratio. The average 28-day compressive strength of the conventional concrete specimens came out to be 29 MPa, but increased to 40 MPa with the addition of 0.25% wt. of cement molasses (28.85 g). It was observed that as the percentage of molasses waste in the concrete mix was further increased by replacing the cement, the compressive strength of the concrete specimens increased gradually and then significantly decreased. The findings shed light on the prospect of using molasses waste instead of cement in the concrete mix. Also, it is worth mentioning that about 30% of the cost–benefit was obtained with reference to that of conventional admixtures available in the market for the production of concrete. However, it is notable that a long-term durability study needs to be conducted before making it viable. This work not only addresses a sustainable and innovative method of waste management (SDG12), but also contributes to low carbon emissions (SDG13). The novelty of this work lies in the fact that no such kind of study has been conducted in Pakistan so far, in addition to the very limited international literature available, and, in particular, no evidence on the compressive strength results at higher molasses dosages, i.e., 1% wt. of cement (113.6 g) and 2% wt. of cement (230.8 g).

Performance and life cycle of Portland limestone cement mixes admixed with gypsum

In this study, the life cycle and performance of normal concrete containing 35% limestone and 2% gypsum made in different ratios of water to binder (w/b) were examined. Its cost and CO2 emissions were found to be 13% and 35% lower compared to the control concrete. However, because of the greater replacement of cement with limestone filler, there is a reduction in its workability, the development of heat and strength, and the penetration resistance of water and chloride ions, especially in the early ages. The addition of gypsum marginally improved these concrete properties, but its quantity should be limited to 2% by weight of the binder. The use of gypsum beyond this limit led to a significant decrease in the properties of concrete. Anorthite, a calcium aluminosilicate mineral, was found in this concrete, and its fractured morphology was found to be more occupied with unreacted angular limestone particles. This low-carbon concrete showed an improvement in compressive strength with decreasing w/b ratios. The limestone reserve in India is abundant and spread evenly across its length and depth, and its use as the main replacement for cement in normal strength mixes would greatly reduce the impact of CO2 on the environment.

Experimental studies on strength and workability of mineral admixture modified cement-based fibre-reinforced self-compacting concrete

ABSTRACT Mineral admixtures such as fly ash (FA), ground granulated blast furnace slag (GGBS), metakaolin (MK), and silica fumes (SF) derived from industries are often referred to as secondary cementitious materials, as partial replacements for cement. Also, the use of fibres significantly enhances the flexural behaviour of concrete. Various kinds of literature highlight the performance of concrete with one or two types of admixtures. In this study, an attempt is made to explore the effect of the use of more than two admixtures viz. FA, GGBS and MK as a partial replacement to cement and fibrofor fibre (FF) on workability and strength properties of based Fibre-Reinforced Self-Compacting Concrete (FRSCC). The FF in Self-Compacting Concrete (SCC) is varied from 1.0 to 2.0 kg/cum. The SCC samples are tested for three curing durations. Based on the experimental investigations, the workability of all the mixes is found to be within the EFNARC limits. The variation in the compressive strength of SCC for various fibre dosages is within 10%, after 28 days of the curing period. It is noted that A-10 mix with fibre dosage of 1.0 Kg/cum yielded the highest compressive, split tensile, and flexural strengths after 56 days of curing, as compared to that of all other variations including conventional SCC mix.

Enhancement of Concrete Performance and Sustainability through Partial Cement Replacement with Biochar: An Experimental Study

Enhancement of Concrete Performance and Sustainability through Partial Cement Replacement with Biochar: An Experimental Study

Effect of waste glass powder as partial cement replacement on fresh properties, mechanical strength, bond, water penetration and thermal conductivity of normal concrete

Effect of waste glass powder as partial cement replacement on fresh properties, mechanical strength, bond, water penetration and thermal conductivity of normal concrete

Assessing the Usage of Barytes Powder and Cuddapah Stone Dust as Supplementary Cementitious Materials in Concrete of Grade M30 and M35

This research studied the effects of using Barytes powder and Cuddapah stone waste as substitutes for cement in M30 and M35 grade concrete using OPC. Cement production is known to harm the environment and consume a lot of energy, making the search for alternative materials to replace cement in concrete important.In this study, different amounts of Barytes powder and Cuddapah stone waste were added to concrete mixes as partial replacements for cement. The resulting concrete was tested for compressive strength and compared to normal concrete. The experiment involved making concrete samples with varying percentages of cement replacement, ranging from 0% to 50%, using Barytes powder, Cuddapah stone waste and Combination. The samples underwent standard curing and testing according to Indian standards.The research analysed the results to find the optimum percentage of cement replacement that provided satisfactory mechanical properties. This study determined the feasibility and effectiveness of using Barytes powder and Cuddapah stone waste as partial replacements for cement in concrete production.

Durability and mechanical properties of concretes with limestone filler with particle packing

This study aims to present alternatives to reduce the demand of cement in concrete production based on particle packing concepts. Physical and mechanical characteristics of concretes, as well as the resistance to chlorides action were analyzed. The tests conducted in this study included compressive strength, chloride migration, capillary absorption tests and wetting and drying cycles in 1M sodium chloride solution. Mixtures containing limestone filler presented satisfactory results compared to the reference mixture with particle packing. Excellent results were obtained for concrete with cement consumption of 253.34 kg.m-3 in terms of compressive strength, binder index, capillary absorption and depassivation time of rebars, thus reinforcing the concept that partial cement replacement by limestone filler yields positive results in these properties. Worse results were obtained for concrete with a cement consumption of 161.86 kg.m-3, because it had a higher proportion of filler than cement. The electrochemical monitoring of the steel bars also shows that the packing of the aggregates was essential to delay the initiation of corrosion.

Evaluating the combined effect of sugarcane bagasse ash, metakaolin, and polypropylene fibers in sustainable construction

The major challenge for the construction industry is to design and produce sustainable construction materials that are efficient in their performance and can be affordable for construction projects. The objective of this study is to determine the viability of incorporating waste products such as sugarcane bagasse ash (SCBA) to produce concrete with polypropylene (PP) fibers. SCBA is an industry waste that has certain pozzolanic properties, however, it shows limited mechanical properties when used as a cement replacement. To improve the mechanical and durability performance, metakaolin (15%) and PP fiber (0.5%, 1%, and 1.5%) were incorporated in the SCBA blend as a ternary additive. Some of the important characteristics explored include compressive strength, tensile strength, density, water absorption, acid resistance, and sorptivity. The study reveals that the incorporation of 15% metakaolin in the composite enhanced the compressive strength by 7%, 8.2%, and 9.1% for PP fiber additions of 0.5%, 1%, 1.5%, while the acid resistance enhanced by 4%, 6% and 8% relative to the control mix for the same value of pp fiber. Furthermore, cost evaluation confirms that the overall costs of concrete with 15% metakaolin and 5% SCBA were 12.2% less than the control concrete, thus making this option economically feasible. This research proves that the inclusion of SCBA, metakaolin, and PP fibers into the concrete mixture brings a sustainable approach that enhances mechanical properties and durability while assisting sugar manufacturing plants in the proper disposal of wastes.

Partial replacement of cement with marble powder and fine aggregate with copper slag

Concrete is the biggest utilized material around the world. With the expanding pace of populace development, framework to should be grown quickly to satisfy the necessities of individuals and for all these an enormous measure of assets are required. The significant one of them is total. In any case, the inordinate utilization of these assets will make an ecological awkwardness. Hence, we have chosen to supplant these significant element of the development business with marble powder and copper slag individually. As we know Concrete is the largest material after food and water. The main constituents of concrete are Cement and Fine aggregate. Many studies have been done to know the environmental impact of cement and concrete. Seeking the adverse effect of high production of cement on environment, we have thought of partial replacement of cement with marble dust and fine aggregate with copper slag in this research.

Performance evaluation of untreated sugarcane bagasse ash as partial replacement of cement on setting time and compressive strength of M15 concrete

Due to its escalating cost, cement, the primary component of concrete, has become a significant issue in Nigeria over time. The use of agricultural wastes such as cow bones, periwinkle shells, rice husks,and sugarcane bagasse as additives to partially replace cement has been made possible by scientific efforts to find alternative and effective materials from large deposits of agricultural wastes. This study examines how adding sugarcane bagasse ash (SCBA) to concrete affects its strength properties. Sugarcane bagasse ash was successfully included in various amounts (0, 2.5, 5.0, 7.5, and 10% by weight of cement). A mix design of 1:2:4 (M15) grade and a water-cement ratio of 0.5 was used to cast 60 concrete cubes measuring (150 x 150 x 150) mm. Concrete's workability and setting time were improved by adding sugarcane bagasse ash to the cement. The outcome revealed a reduction in concrete density with an increase in percentage replacement of sugarcane bagasse ash. Addition of sugarcane bagasse ash to cement increased the concrete's workability and speed of setting. The results showed that concrete density decreased as sugarcane bagasse ash replacement percentage increased. This is not unrelated to the fineness of sugarcane bagasse ash, which makes the cementitious matrix and aggregate interface more intense and lighter. Concrete's compressive strength was discovered to be decreased by the usage of sugarcane bagasse ash. Between 0, 2.5, 7.5, and 10% sugarcane bagasse ash, the average compressive strength measured at 28 days was found to be 25.93, 25.19, 23.70, 20.30, and 18.96 MPa, respectively. 10% sugarcane bagasse ash concentration was suggested as the optimal level to employ for improving concrete characteristics.

Mitigating autogenic shrinkage in high‐performance concrete using wollastonite: A structural enhancement approach

AbstractThis study investigates the influence of wollastonite fiber as a reinforcement in high‐performance concrete (HPC), focusing on its potential to mitigate autogenic shrinkage and enhance overall structural properties. HPC known for its superior strength and low permeability, often suffers from intensified autogenic shrinkage, leading to micro‐cracking and compromising durability. To address this challenge, wollastonite was incorporated at different substitutions (0%, 5%, 10%, and 15%) for both cement and aggregate. The experimental program involved a systematic evaluation of compressive strength, flexural strength, porosity, water absorption, and corrosion resistance with tests conducted at different curing periods. We found that the addition of 10% wollastonite significantly enhances compressive strength (up to 20% after 90 days) and flexural strength (maximum improvement of 21%). The water permeability was decreased by 29% and improved resistance to steel reinforcement corrosion, demonstrating enhanced durability compared to conventional HPC. However, diminishing returns were observed at higher wollastonite replacement levels (15%), indicating a threshold beyond which mechanical and durability benefits were reduced due to potential issues with fiber dispersion and workability. Our findings suggest that wollastonite is a promising, cost‐effective additive for improving HPC. The study contributes new understandings into optimizing HPC mixtures for greater durability and sustainability, while also reducing the environmental footprint through partial cement replacement. Future research is needed to explore the long‐term performance of wollastonite‐reinforced HPC under different environmental conditions and its combination with other supplementary cementitious materials for further enhancement.

Investigation of strength, durability, and microstructure properties of concrete with waste marble powder as a partial replacement of cement

Purpose Cement plays a significant part in concrete, and with the increasing demand for concrete, cement output varies day by day, allowing production to carbon dioxide emissions. As well as marble processing creates stone slurry and solid discards. These are often dumped irresponsibly on open land, polluting the soil. This improper disposal of marble waste is a major environmental concern. This study aims to propose a sustainable solution for reusing this waste material as a concrete additive. Design/methodology/approach A total of 135 concrete cubes of size 150 × 150 × 150 mm, 54 concrete cylinders of size 150 mm dia. and 300 mm height and 54 concrete beams of size 150 × 150 × 700 mm were cast. The replacement was 0%, 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17.5% and 20% by weight of cement with marble dust to create M30 concrete with a water-cement ratio of 0.45. The test was performed to find the compressive strength (CS), flexural strength (FS) and split tensile strength. Also, durability tests like rapid chloride penetration test (RCPT), acid attack, ultrasonic pulse velocity (UPV) and water permeability test were performed. Findings After 7 and 28 days of curing, it was found that replacing 5% of cement with marble powder led to an initial strength improvement of up to 25% for both curing periods. However, further increases in marble dust resulted in an inconsistent decrease in strength for all the mixtures. Also, durability properties like acid attack test, water permeability test and RCPT, showed good performance at the optimum percentage of waste marble powder (WMP) as cement replacement. The microscopic analysis revealed a denser pore structure at lower WMP replacement levels, likely due to the powder filling in gaps. Originality/value This study reveals that by substituting 5% (optimum) of cement with WMP, there was CS improvement up to 8.4% and 17% for both 7 and 28 days of curing. WMP is typically finer than cement particles and fills the voids in the concrete more effectively, resulting best performance at optimum percentage against RCPT, UPV, acid attack and water permeability.

Effect of Olive Waste Ash as a Partial Replacement of Cement on the Volume Stability of Cement Paste

Over the last decades, concrete has been excessively prone to cracks resulting from shrinkage. These dimensional changes can be affected by the incorporation of supplementary cementitious materials. This work used olive waste ash (OWA), which could substantially tackle this problem and achieve sustainability goals. For this issue, five cement paste mixes were prepared by replacing cement with OWA at different percentages varying from 0 to 20% by weight with a constant increment of 5%. The water-to-cement ratio was 0.45 for all mixes. Compressive strength and flexural strength were investigated at 7, 28, and 90 days. In addition, three shrinkage tests (drying, autogenous, and chemical) and expansion tests were also conducted for each mix and measured during 90 days of curing. The experimental findings indicated that there was a loss in compressive and flexural strength in the existence of OWA. Among all mixes containing OWA, the samples incorporating 10% OWA exhibited maximum strength values. Furthermore, the chemical and autogenous shrinkage decreased with the incorporation of OWA. However, the drying shrinkage decreased at lower levels of substitutions and increased at higher replacement levels. In addition, there was a growth in expansion rates for up to 10% of OWA content, followed by a decrease at higher levels (beyond 10%). Additionally, correlations between these volumetric stability tests were performed. It was shown that a positive linear correlation existed between chemical shrinkage and autogenous and drying shrinkage; however, there was a negative relationship between chemical shrinkage and expansion.

Performance of Pervious Concrete with Ground Granulated Blast Furnace Slag (GGBS) as Partial Replacement for Cement

Performance of Pervious Concrete with Ground Granulated Blast Furnace Slag (GGBS) as Partial Replacement for Cement

Sustainable lightweight self-compacting concrete with coal bottom ash as aggregate and cement replacement

This study aims to examine the impact of utilizing coal bottom ash (CBA) sourced from an inactive power plant on the fresh and hardened properties of lightweight self-compacting concrete (LWSCC). To evaluate the workability of the LWSCC mixtures, slump flow, L-box, and sieve segregation tests were performed. The mechanical and physical properties were assessed through dry density, compressive strength and ultrasonic pulse velocity (UPV) tests. A total of five concrete mixes were developed: a control mix and four additional mixtures in which natural coarse aggregate was fully substituted with coal bottom ash aggregate (CCBA). Additionally, Portland cement was partially replaced with coal bottom ash powder (CBAP) at levels of 15%, 20%, and 25%. The results indicated that the use of CBA as a coarse aggregate enhanced the workability of LWSCC, though workability decreased as the proportion of CBAP increased. Nonetheless, the workability of all mixes remained compliant with the standards specified by the French Association of Civil Engineering (AFGC). Minimal variations in dry density and compressive strength were observed with the incorporation of CBA; however, these values remained within the acceptable limits for structural lightweight concrete. Furthermore, the UPV test demonstrated favorable durability for all LWSCC mixtures. Strong linear correlations were identified among the various measured properties, reinforcing the conclusion that CBA serves as an effective replacement for natural coarse aggregate. Moreover, the use of 15% CBAP as a partial substitute for Portland cement proved to be a feasible option for producing sustainable LWSCC.

Thermal activation of multi-recycled concrete powder as supplementary cementitious material for repeated and waste-free recycling

Utilizing powder generated during concrete recycling process is considered crucial for achieving complete recycling of concrete waste. However, integrating recycled concrete powder (RCP) often reduces cementitious mixture performance. This study aims to enhance RCP characteristics through thermal activation, facilitating its recycling as cement replacement over multiple recycling cycles. RCPs from three cycles of concrete recycling were heat-treated at 200 °C, 400 °C, 600 °C, and 800 °C for 2 h, and their chemical composition was analyzed before and after treatment. Subsequently, the RCPs replaced cement in mortar by 10 %, 20 %, and 30 %. Various properties of the mortars, such as flow, mechanical strength, water absorption, and drying shrinkage, were tested. The results showed a general decline in mortar properties with increasing RCP replacement ratios and recycling cycles. However, RCPs activated at 600 °C and 800 °C enhanced compressive and flexural strengths by up to 19 % and 16 %, respectively, and enhanced shrinkage resistance by 19 %. Particularly, the three-times RCP activated at 800 °C achieved mechanical performance comparable to standard mortar at 10 % replacement, meeting strength grading requirements per industry standards. This study demonstrates a viable pathway for the repeatable and waste-free recycling of concrete, contributing to more sustainable construction practices.

Incorporating geranium plant waste into ultra-high performance concrete prepared with crumb rubber as fine aggregate in the presence of polypropylene fibers

Abstract This research examines the efficiency of ultra-high-performance concrete (UHPC) when utilizing geranium plant (GP) ash, which is subjected to different curing temperatures ranging from 300 to 900°C for 3 h of burning time. The GP ash is used as a replacement for cement in varying amounts (10, 20, 30, 40, and 50 wt%). Crumb rubber powder is utilized as a substitute for fine aggregate. Polypropylene fibers have been used to improve concrete performance. The performance of UHPC is evaluated by assessing its mechanical qualities, such as flexural strength, splitting tensile strength, and compressive strength. The sorptivity test is also evaluated as a component of it. Scanning electron microscopy is used to analyze UHPC after exposure to temperatures as high as 900°C. The findings demonstrated a notable enhancement in the mechanical characteristics of all mixtures. The most favorable mixtures were achieved with proportions of 50, 40, 40, and 20% for mixtures including GP waste incinerated at temperatures ranging from 300 to 900°C. Furthermore, the optimal outcome is achieved when 40% substitution is performed at a temperature of 700°C, resulting in notable enhancements of 14% in compressive strength, 30% in flexural strength, and 17% splitting tensile strength, respectively. At a high temperature of 700°C, the decrease in strength increased to approximately 37–40% as a result of the initial removal of carbon dioxide from calcite at temperatures ranging from 600 to 900°C and reached 56% at 900°C. Great resistance to sorptivity, as well as a dense and compact microstructure with a high content of calcium and silicon, was obtained.