Cement Replacement In Mortar Research Articles

Valorization of coffee cherry waste ash as a sustainable construction material

This study explores the potential of treated coffee cherry waste (T-CCW) as a partial replacement of cement in mortar. T-CCW was characterized and incorporated into pastes and mortars at 5 %–25 % cement replacement. The main objectives were to examine the fresh and hardened properties, hydration, and environmental assessment. Results showed that the high specific surface area and porous structure of T-CCW particles increased water demand and accelerated setting times. T-CCW incorporation of up to 15 % enhanced compressive strength at all curing ages due to improved hydration and limited pozzolanic reactions. Ultrasonic pulse velocity indicated good homogeneity and compactness in T-CCW blended mortars. Microstructural analysis revealed that T-CCW enhanced cement hydration, leading to a denser matrix. Environmental analysis showed a reduced embodied carbon and cement intensity index compared to the control mix. Overall, the optimal performance was observed at 15 % T-CCW replacement, significantly improving engineering properties and environmental impact. Further, the fishbone diagram addresses various factors to optimize the use of T-CCW as a cementitious composite. These findings demonstrate the potential of T-CCW as a sustainable construction material, offering a promising pathway towards environmentally friendly and resource-efficient building practices while addressing waste management in the coffee industry.

Effect of titanium dioxide on fresh and mechanical properties of Mortar: A review

Nanotechnology-based engineering approaches are rapidly developing throughout the world. Modern, cutting-edge nanotechnology has proven useful in a variety of technical applications. In emerging and developed countries, increasing infrastructure needs a considerable amount of cement, which has a significantly impact on the environment and human health, resulting in greenhouse gas emissions and severe acute respiratory illnesses (asthma and silicosis, respectively). To overcome such difficulties, cement consumption in building materials must be reduced. Several novel extra materials have lately been introduced to improve the performance of mortar. Nano-titanium dioxide (NT) in cement mortar is widely used in green building construction because NT capable to the degradation of air pollution, self-cleaning, and enhancing mechanical, microstructural, and durability properties. In this paper, the effect of NT on fresh and hardened properties of cement mortar has been discussed. For the collection, screening and implementation of data for review paper PRISMA analysis and VOSviewer technique was used. Existing literature indicates that the reduction in workability 15% − 20% whereas improvement in compressive strength (CS) up to 15% and tensile strength up to 45% was noted with NT in mortar. Current research supports using NT as a cement replacement in mortar. Aside from the key findings, some identified gaps, problems, and future scope challenges have been presented in order to develop NT based mortar as a sustainable material in the building sector.

A Comprehensive Exploration on the Effect of Waste Glass Powder as a Partial Replacement of Cement in Mortar: A Review, Analysis, and Modeling Investigation

A Comprehensive Exploration on the Effect of Waste Glass Powder as a Partial Replacement of Cement in Mortar: A Review, Analysis, and Modeling Investigation

Influence of setting time and compressive strength for coal bottom ash as partial cement replacement in mortar

Environmental degradation from forestry practices to extract limestone from mountains, as well as subsequent calcination in cement factories and dumping of coal bottom ash (CBA) waste from thermal power plants, are among the wastes from industry. However, it is essential for the construction industry to look for sustainable solutions to mitigate the negative impact on the environment. In order to promote an environmentally friendly and sustainable ecosystem, the use of recycled CBA waste as a partial substitute for cement in the manufacturing process has significant potential to mitigate the environmental damage caused by the two distinct sectors of cement and waste management. A series of six mortar preparations were prepared, each containing varying percentages of CBA as a partial substitute for cement. The percentages used ranged from 0% to 50% by weight of cement. The time tests were performed on freshly prepared pastes. All samples were cured with water until the respective test time was reached. The experiment included the evaluation of the compressive strength of hardened mortar cubes at three different time intervals: 7, 14 and 28 days. The findings of the study demonstrate that the incorporation of CBA as a partial substitute for cement affects both the setting time and the compressive strength of the mortar. It has been shown that the use of up to 20% CBA as a cement replacement effectively increases the compressive strength of the mortar. Conclusively, the successful use of CBA as a partial substitute for cement in the manufacture of mortar has the potential to reduce the amount of cement consumed, eliminate the need for landfill space for waste disposal, and contribute to the production of a more sustainable environment, thereby promoting a better lifestyle for the surrounding population.

Characteristics of waste concrete powders from multi-recycled coarse aggregate concrete and their effects as cement replacements

The utilization of fine powder generated from crushing for recycling construction waste is a challenging task for the transition to zero waste and sustainable development. This study investigated the physical and chemical characteristics of recycled concrete powders (RCP) generated by repeated recycling of concrete and discussed their application as a partial replacement for cement in mortar. RCPs smaller than 0.15 mm were obtained from three different generations of multi-recycled coarse aggregate concrete, respectively, which replaced cement by 10%, 20% and 30%. The results showed that the RCP became more porous, rough and less dense with an increasing number of concrete recycling. Consequently, the properties of mortar containing RCP decreased as a function of replacement ratio and the number of concrete recycling. By reducing the replacement ratio, the properties of mortar containing RCP obtained from second-generation concrete could be comparable to those of mortar containing RCP obtained from first-generation concrete. However, for mortar made with RCP obtained from third-generation concrete, even at a 10% replacement ratio, the performance was lower than that of the previous-generation mortar with 30% RCP, indicating the need for modification for proper utilization of RCP obtained from repeatedly recycled aggregate concrete.

Performance of bamboo biochar as partial cement replacement in mortar

Pyrolysis under limited oxygen conditions at high temperatures is used to produce bamboo biochar. The construction industry often utilizes cement, which is a significant contributor to greenhouse gas emissions and environmental damage. To decrease the use of cement, this study examines the effectiveness of bamboo biochar as a partial cement replacement in mortar. The study determines the optimal percentages of bamboo biochar as a partial replacement and evaluates its mechanical performance in terms of compressive and flexural strength. The percentages tested include a smaller range of 0.5%, 1%, 1.5%, and 2%, and a higher range of 5%, 10%, 15%, and 20%. The samples are cured for 7, 14, and 28 days. The study concludes that 10% is the optimal percentage replacement for compressive strength, while 5% is optimal for flexural strength. Additionally, the study finds that according to ASTM C618-19, bamboo biochar is best classified as a filler rather than a pozzolan, as it does not meet the class N-pozzolan requirement.

Application of pyrophyllite in high-temperature treated building materials

Phyllosilicate mineral pyrophyllite is predominantly used in the ceramic industry because it exhibits high refractoriness. Due to its thermal transformation into mullite, pyrophyllite is stable at elevated temperatures, making it a suitable mineral additive for refractory non-shaped materials and various ceramic shaped products. In this study, pyrophyllite is employed as 50 % clay replacement in the ceramics and up to 30 % cement replacement in mortars. Physico-mechanical properties were investigated. The firing shrinkage in the ceramics treated at 1200 ?C was reduced by pyrophyllite addition. Pyrophyllite acted as additional pozzolana during cement hydration. Within the microstructure, it formed micro-reinforcement in the shape of crystalline folia, which improves the mechanical properties of ordinary Portland cement, high aluminate cement, and blended cement mortars. The investigation proved the efficiency and suitability of pyrophyllite employed as a substitution for clay in ceramics and a cement replacement in mortars.

Characteristics of Combined Rice and Wheat Husk Ashes as a Partial Replacement for Cement in Mortar

The potential to recycle and utilize agricultural waste as a building material has been demonstrated in a variety of applications. The goal of this study was to assess the feasibility of partially substituting combined rice and wheat husk ashes (CORWHA) for cement in mortar. The two agricultural waste ashes, rice husk and wheat husk, were evaluated separately before being combined. Both husks were burned separately in an open room to reduce volume before being cremated for 2 hours at a regulated temperature of 600 °C to eliminate carbon and generate reactivity. The chemical and physical properties of the ashes were evaluated after grinding and sieving to determine their cementitious qualities before developing and testing 12 mix proportions of CORWHA and cement for mortar production. The mixing was done at three different percentages of cement replacement: 20, 30, and 40%. According to the findings, the maximum cement replacement yielding 5.98 MPa mortar strength is 30%, with a mixed proportion of 11% wheat husk ash (WHA) and 19% rice husk ash (RHA). It was also found that 95% of RHA is silica and 1.67% is alkaline, while 63% of WHA is silica and 12.16% is alkaline, which is good for preventing porosity and corrosion of reinforcement bars. Doi: 10.28991/CEJ-2022-08-04-04 Full Text: PDF

Performance of waste glass powder as a pozzolanic material in blended cement mortar

In this study, the pozzolanic activity of finely ground waste glass powder (WGP) used as a partial cement replacement in mortars was investigated, and the WGP particle size, WGP content, and curing age were selected for analysis. Tests to determine the fluidity, compressive strength, scanning electron microscopy (SEM), energy dispersive X–ray spectroscopy (EDS), X–ray diffraction (XRD), Thermo–gravimetry analysis (TGA), Differential thermal gravity (DTG) and Fourier transform infrared spectroscopy (FTIR) were performed on a blended mortar. The results showed that when the WGP particle size was 20–44 μm and the WGP content was 20%, the fluidity of the slurry was higher than that of the control group, and the slurry exhibits good cohesion and water retention performance. When the WGP particle size ranges were 74–150 μm and 44–74 μm, the compressive strength of the blended mortar was smaller than that of the control group for all curing days regardless of the WGP content. When the WGP particle size was 20–44 μm, the compressive strength was lower than that of the control group at 7 d of curing, whereas it was 3.5% and 9.6% higher than that of the control group at 28 d and 90 d curing, respectively, with a WGP content 20%. When the WGP particle size was 15–20 μm, the compressive strength did not significantly increase compared with when the WGP particle size was 20–44 μm for the same WGP content, but slightly decreased. SEM and EDS showed that when the WGP particle size was 20–44 µm and the WGP content was 20%, the hydration products in the microstructure of the cement slurry were abundant, whereas pore cracks were few. This was additionally confirmed by XRD and TGA–DTG results, thereby verifying the formation of the lowest content of calcium hydroxide (CH) and the highest content of calcium silicate gel in the blended mortar. Variations in the Si–O and Al–O bond intensities shown in the FTIR spectrum supported this conclusion. Furthermore, the TGA–DTG results showed that the increase in calcium silicate gel content from 28 d to 90 d was higher than that from 7 d to 28 d, and that the activity of the WGP was more significant in the later curing period.

Performance of Ladle Furnace Slag in Mortar under Standard and Accelerated Curing

This research preliminarily investigated the suitability of a locally available ladle furnace slag (LFS) as a partial replacement of cement in mortar. The raw material was first characterized to obtain its chemical and physical properties through particle size distribution, X‐ray fluorescence (XRF), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Later, the raw LFS was classified into two categories: (i) raw LFS and (ii) sieved (passing through #200 sieve) LFS and incorporated in mortars as a partial replacement of cement. Mortar prisms with 5, 10, 15, 20, 25, and 50% LFS (raw and sieved) were prepared and cured under normal temperature (NTC) for 7, 28, and 56 days. Additional mortar prisms (with raw and sieved LFS) were prepared by curing them under high‐temperature accelerated curing (HTAC) for 7 days. The characterization tests suggest that CaO, SiO2, MgO, and Al2O3 are the main compounds of raw LFS used in this study. The mineralogical phases present in the raw slag are calcio‐olivine, akermanite, α‐quartz, merwinite, magnetite (Fe3O4), and calcium‐aluminium oxide. Both raw and sieved LFS‐blended mortars yield good consistency up to 25% cement replacement in mortars. The compressive strength of NTC mortar suggests that 5% and 10% replacement of cement with raw and sieved LFS yields higher strength than the control mortar. Seven days strengths of raw and sieved LFS blended mortars obtained for HTAC are closely comparable to that of 28 days under NTC. This study recommends that LFS could be a sustainable supplementary material to use as a partial replacement of cement in mortar, preferably up to a level of 15% for standard works.

Exploring the Properties of Mortar Containing Incineration Fly Ash

Fly Ash (FA) is one of the waste materials generated from the combustion of solid waste through incinerator and contains hazardous substances. Further treatment to the ash needs to be done to avoid further environmental destruction. As an alternative solution for this problem, FA is used as a replacement material for cement in the mortar. The main objective of this study is to explore the potential use of FA as partial replacement of cement in mortar. The percentage of FA used to replace the cement in this study is 0%, 5%, 10%, 15% and 20%. Several important tests were conducted to identify main properties of the mortar such as compressive strength, water absorption, density and ultra-pulse velocity. Mortar containing 15% of fly ash has the highest of compression strength which is 35 MPa after 28 days. Besides, the mortar containing 5% of fly ash has the highest result of water absorption test and density test whereas mortar containing 20% of fly ash has the highest value for pulse velocity after 28 days. Thus, mortar containing fly ash has good physical and mechanical properties.

Use of glass powder residue as an eco-efficient supplementary cementitious material

Supplementary cementitious materials (SCM) are proven to be an efficient alternative to lowering concrete carbon footprint by partially replacing cement on its mix design. Glass powder residue (GPR) has great potential to improve concrete’s mechanical performance, and its durability by suppressing the alkali-silica reaction (ASR). However, those qualities can only be achieved by reducing the GPRs particles sizes below cement to fill the binder gaps. In this context, the main objective of this research was to evaluate the grinding parameters to obtain GPR, resulting from the polishing process in the flat glass industry, with the desired properties as SCM. Grinding time was monitored and correlated with glass particle size distribution (GPSD). Optimum GPSD was crossed with mechanical characteristics and ASR reduction in mortars. GPR was tested in 0%, 10%, 15%, 20% and 25% of partial replacement in Brazilian Portland-Pozzonlan cement in mortars and pastes. Consumption of calcium hydroxide was also observed. Four hours of grinding was shown to be the optimum grinding time to lower the GPSD below cement. Moreover, tests suggest that 20% of grinded GPR can be used as partial cement replacement in mortars without lowering its compressive strength and showed positive mitigation in alkali-silica reaction at 14 days of observation. According to the results for the parameters studied, although mortars with 15% of GPR partial replacement had the highest efficiency and performance index, 20% can be considered the maximum GPR replacement content. Any increase represents a decrease in efficiency and performance. The eco-efficiency is observed with the reduction of energy needed to produce cement, as the level of replacement by GPR increases. Therefore, grinded GPR can be an alternative in the production of more environmentally friendly cementitious materials.

Waste Slag from Heating Plants as a Partial Replacement for Cement in Mortar and Concrete Production. Part I—Physical–Chemical and Physical–Mechanical Characterization of Slag

Numerous factors influence the complexity of environmental and waste management problems, and the most significant goal is the reuse of materials that have completed their “life cycle” and the reduction in the use of new resources. In order to reduce impact of waste slag on the environment, in the present study, waste slag, generated in heating plants after lignite combustion, was characterized in detail and tested for application as a replacement for cement in mortar or concrete production. For physical–chemical characterization of slag, different experimental and instrumental techniques were used such as chemical composition and determination of the content of heavy metals, investigation of morphological and textural properties, thermal analysis, X-ray, and infrared spectroscopy. Physical–mechanical characterization of slag was also performed and included determination of activity index, water requirement, setting time and soundness. A leaching test was also performed. Presented results show that waste slag may be used in mortar and concrete production as a partial cement replacement, but after additional combustion at 650 °C and partial replacement of slag with silica fume in the minimal amount of 12%. The maximal obtained cement replacement was 20% (17.8% slag and 2.2% of silica fume).

Evaluation of Industrial Ashes in Cement Replacement in Mortars

It is well known that cement production has a high negative impact on the environment. This fact, in conjunction with the high demand for this product worldwide, has created concern over how to reduce its use. Various materials have been tested as partial or total replacements for cement, one of which is biomass ash. In this article we report the preparation of test samples of mortar using two types of biomass ash, the first of forest origin and the second agricultural; both were used to replace cement in proportions of 10%, 20% and 30%. The test samples were assayed for compression and flexion after 7, 14, 28 and 90 days. After 28 days the apparent density, open porosity, absorption, capillarity and ultrasound velocity were measured. All the results of the series were compared with a control mortar. In the compression and flexion assay, a higher resistance than the control mortar was obtained with 10% replacement of both types of ash after 90 days, however with 20% and 30% ash the results were inferior to traditional mortar. There was an increase in the absorption percentage and porosity as the percentage of cement replacement increased; this increase was smaller for ash from agricultural biomass than ash from forest biomass. The density diminished as the percentage of replacement material increased, but the change was smaller with ash from agricultural biomass; this may be attributed to a filler effect produced by its granulometric distribution.

Use of Slag from the Combustion of Solid Municipal Waste as A Partial Replacement of Cement in Mortar and Concrete.

In Europe, the use of wastes in the cement and construction industry follows the assumptions of sustainability and the idea of circular economy. At present, it is observed that cement plants introduce wastes to the cement in the form of so-called mineral additives. The most often used mineral additives are: fly ash with silica fume, granulated blast furnace slag and silica fume. The use of mineral additives in the cement is related to the fact that the use of the most expensive component of cement—Portland cement clinker—is limited. The purpose of the article is a preliminary evaluation of the suitability of slag from the municipal solid waste incineration plant for its use as a replacement of cement. In this article, slag from the municipal solid waste incineration (MSWI) replaces cement in the quantity of 30%, and presents the content of oxides and elements of slag from the MSWI. The obtained results are compared to the requirements that the crushed and granulated blast furnace slag need to meet to be suitable for use as an additive of type II to the concrete. The conducted analyses confirmed that the tested slag meets the requirements for the granulated blast furnace slag as an additive to the concrete in the following parameters: CaO ≤ 18.0%, SO3 ≤ 2.5% and Cl ≤ 0.1%. At the same time, mechanical features were tested of the designed mortars which consisted of a mixture of Portland cement (CEM I) with 30% of slag admixture. The designed mortar after 28 days of maturing reached a compressive strength of 32.0 MPa, and bending strength of 4.0 MPa. When compared to the milled granulated blast furnace slag (GBFS), the obtained values are slightly lower. Furthermore, the hardened mortars were subject to a leachability test to check the impact on the environment. Test results showed that the aqueous extracts from mixtures with 30% of slag admixtures slightly exceed the limits and do not pose a sufficiant threat to the environment as to eliminate the MSWI slag from economical use.

Mechanisms of chloride and sulfate removal from municipal-solid-waste-incineration fly ash (MSWI FA): Effect of acid-base solutions

A general approach to managing municipal solid waste is by incineration. Unfortunately, large amounts of municipal-solid-waste-incineration fly ash (MSWI FA) is produced in the process, with their heavy metals content posing further problems to the environment. One fundamental treatment of MSWI FA heavy metals is called solidification-stabilization, where MSWI FA is solidified in cement-based materials to cap hazardous elements from being released into the environment. Mortar formed from this cement mixed with MSWI FA suffer from decreased compressive strength due to their chloride and sulfate contents. Thus, pre-treatment of MSWI FA to remove these salts before producing mortar is desirable. This study investigated treating MSWI FA with deionized water, 0.01 M and 0.1 M nitric acid, and 0.1 M and 0.25 M sodium carbonate to remove chloride and sulfate. Physical and chemical structures of treated and untreated MSWI FA was studied to understand the chloride and sulfate removal mechanisms. Treated MSWI FA was used as cement replacement in mortar, and the compressive strength was tested. Results suggest that all of the treatment solutions tested in this study can equally remove chloride (around 250,000 mg/kg), but sodium carbonate can remove sulfate at the highest extent (15,821 mg/kg). In addition, mortar with deionized-water-treated MSWI FA gave the highest compressive strength. Heavy metals leaching was tested by the Toxicity Characterization Leaching Procedure (TCLP) method, with results passing the standard.

Use of Waste Glass as A Replacement for Raw Materials in Mortars with a Lower Environmental Impact

Glass waste used in mortars or concretes behaves similar to cement, with resulting environmental benefits. In this light, the behavior of glass powder of various particle sizes has been analyzed as a cement replacement in mortars, in an attempt to minimize the loss of strength and durability, and maximize the amount of materials replaced. The dry density, water accessible porosity, water absorption by immersion, capillary absorption coefficient, ultrasonic pulse velocity and both compressive and flexural strengths were studied in the mortars. Furthermore, a statistical analysis of the obtained results and a greenhouse gases assessment were also performed. In view of the results obtained, glass powder of 38 microns allows up to 30% of the cement to be replaced, due to the filler effect combined with its pozzolanic activity. Moreover, it has been observed that glass powder size is one of the factors with the greatest influence among the properties of porosity, absorption and capillarity. On the other hand, in the mechanical properties, this factor does not contribute significantly more than the amount of glass powder. Finally, the greenhouse gasses analysis shows that the incorporation of glass powder reduces the CO2 emissions associated with mortar up to 29.47%.

Combination of Biochar and Silica Fume as Partial Cement Replacement in Mortar: Performance Evaluation Under Normal and Elevated Temperature

Utilization of waste derived materials to replace part of cement is an effective strategy for cost effective and sustainable concrete constructions. This study investigates a blend comprising of different proportions of silica fume (SF) and biochar, prepared from wood (MWBC) and food waste (FWBC) respectively, to replace 10 wt.% of cement in mortar mixes. Mechanical and permeability properties of the developed cement-biochar composites were tested under normal and elevated temperature (500 °C). Experimental results show that combination of biochar and silica fume enhance compressive strength (by up to 18–20%) and structural efficiency (strength to density ratio) compared to control mixtures. Water permeability results confirmed that blend of biochar and silica fume play a significant role in reducing capillary water absorption by 50–60% compared to control mortar, which is attributed to filler effect and water retention by fine biochar particles. Mortar with combined admixtures (biochar and SF) had higher resistance to damage at elevated temperature, which was evident from 22% higher strength and lower permeability (22–24%) compared to control mix after thermal damage. Finally, economic analysis highlights that using blend of biochar and silica fume to replace cement is more economic than using only silica fume, due to relatively lower cost and waste recycling associated with biochar production. In summary, this study suggests that biochar may be a sustainable and economic alternative to reduce usage of cement and more expensive pozzolanic fillers in cementitious composites.

Characterization of coal bio ash from wood pellets and low-alkali coal fly ash and use as partial cement replacement in mortar

Coal is increasingly replaced by biomass at the power plants. This results in new types of fly ashes, e.g. coal bio ash (CBA), where low-alkali coal fly ash (CFA) is injected to the boiler furnace during incineration of wood pellets to hinder corrosion and maintain the necessary thermal efficiency of the fuel. An assessment of the properties of this new type of ash is important for the utilization of this resource. This study reports an investigation of the filler behaviour and pozzolanic activity of CBA, when used as a partial cement replacement. Traditional CFA was used for comparison and CBA was shown to be a more favourable substitute compared to CFA. This study has shown, that by injecting CFA into the boiler furnace, wood fly ash is transformed from being a waste by-product, into a usable resource in concrete production.

PHYSICAL AND MECHANICAL PROPERTIES OF CEMENT MORTAR USING LIME AND BAMBOO-ASH AS PARTIAL REPLACEMENTS

The effect of varying different proportion of bamboo ash and lime as partial replacement for cement in mortar were studied. Bamboo stalks were collected and burned into bamboo ash in furnace. The results of the physical and mechanical properties of the cement and aggregate used were within the requirements stipulated by relevant standards. The mix proportion 1:6 was used out of which 2%, 4% of bamboo ash and 2%, 4% of lime were used to partially replace cement in the mortar. The compressive strength of most of the mortar cubes increases with curing days and their values lie within the required strength of 2.5 N/mm2 – 6.5 N/mm2 as stipulated by relevant codes. The water absorption rate was observed to increase with increase in bamboo ash and lime content, while the density decreases as the percentage of bamboo ash and lime in the mortar increases by mass. The study therefore can be concluded that in the presence of significant proportion (i.e. 4% or more) of bamboo ash the strength of mortar increased hence making it adequate for the production of masonry mortar and reduces building failure.