Mortar Mixtures Research Articles

Investigation of anionic group characteristics of PCEs on the behaviour of fly ash cementitious systems

The compatibility of polycarboxylate-based water-reducing admixtures (PCEs) having different carboxylate, phosphate and sulfonate anionic groups with paste and mortar mixtures containing fly ash (FA) was investigated. It was found that, with an increase in the FA content of the mixtures, the PCE requirement for the target flow decreased and the consistency retention performance was improved due to the decrease in the amount of hydrated cement. An improvement in rheological parameters was observed with an increase in FA content from 15% to 30%. However, increasing the FA replacement level beyond 30% caused stability problems in the mixtures. This problem was eliminated with the addition of PCE. In the paste and mortar mixtures, regardless of the FA substitution ratio, the best performance was obtained with PCEs containing 7% and 5% phosphate and sulfonate, respectively. The most suitable FA replacement ratio in terms of rheological parameters and 28-day compressive strength was 30% and 15%, respectively. It was observed that the PCE anionic group content did not have any significant effect for all FA substitution ratios.

Coal gangue in asphalt pavement: A review of applications and performance influence

The comprehensive utilization of coal gangue is low, and this causes serious environment problems and security risks. The physical and chemical properties of coal gangue were analyzed in this paper, and the estimated value of different chemical components of coal gangue was counted. The physical properties of coal gangue aggregate were analyzed, and performance and its influencing factors of base course mixture with coal gangue aggregate were studied. The influence of coal gangue powder and coal gangue aggregate on performance of asphalt mortar and asphalt mixture was analyzed, and possible influencing factors and function mechanism were discussed. The results showed that heavy metal elements of coal gangue applied into asphalt pavement is not seeped out. The crushing value, water absorption and flat elongated particles content of coal gangue aggregate are generally high, but the compressive strength of base course with coal gangue aggregate is verified to meet the strength requirement. The performance, volume stability and durability of base course with coal gangue aggregate are closely related to aggregate gradation, the type and dosage of cementations materials and aggregate. The high temperature performance, temperature susceptibility and viscosity of asphalt mortar are improved by the addition of different coal gangue powder, and improvement effect of activated coal gangue powder on asphalt mortar performance is better. The low temperature performance and adhesion property of asphalt mortar with chemical activated coal gangue powder are improved. The physical reaction between asphalt and different coal gangue powder is only taken place. The temperature stability of asphalt mixture with coal gangue coarse aggregate has achieved the specification requirement. The water stability and low temperature fracture performance of asphalt mixture with fine aggregate replaced by coal gangue are improved. However, the high temperature performance of above mixture is lower than conventional hot mix asphalt mixture. The research results will provide reference for coal gangue applied into asphalt pavement.

Experimental Investigation and Classification of Wastewater Treatment Sludge as Pozzolan for Cement

This paper presents an investigation conducted to evaluate wastewater treatment sludge for potential use as a cement extender or pozzolan. Two varieties comprising the digested wastewater sludge (DWWS) and activated wastewater sludge (AWWS) materials, were finely ground then calcined at 750 °C for 30 min. Subsequently, the calcined sludge waste materials were blended with ordinary Portland cement CEM I 52.5 N at 0, 10, 20, 30% DWWS or AWWS, and used to prepare mortar mixtures at proportions of 1:3:0.61 cement to sand to water. Various tests were conducted including workability, compressive strength, pozzolanic activity with lime, drying shrinkage and alkali-silica reaction. It was found that both varieties of the sludge waste materials, once blended with CEM I at 20% DWWS or 20% AWWS, satisfied the ASTM C618 criteria for Class C pozzolan, and may be classified as CEM II /A-P 32.5 N,R cement type of EN 197-1/SANS 50197-1. The overall performance of DWWS was relatively better than that of AWWS.

Effect of nano-TiO2 size and utilization ratio on the performance of photocatalytic concretes; self-cleaning, fresh, and hardened state properties

In this study, photocatalysis technology was used to reduce water pollution. Decolorization of Reactive Black 5 using nano-TiO2 (NT) as a photocatalyst was investigated by adsorption and degradation experiments. Effects of NT particle size and utilization ratio on the time-dependent flow performance, compressive-flexural strength, and Bohme abrasion resistance of cementitious systems were investigated. In addition to the NT-free control mixture, a total of six photocatalytic self-cleaning mortar mixtures (PSCM) were prepared using NT in two different particle sizes (28 and 38 nm) and three different ratios (0.5%, 1%, and 1.5%). The PSCM sample containing 38 nm NT exhibited superior performance in terms of photocatalytic properties compared to the 28 nm state. It was observed that the flow performance of PSCM mixtures with NT substitution is adversely affected regardless of the NT type. Mixtures containing NT with a lower particle size (28 nm) had higher compressive and flexural strengths.

Algorithms to create realistic virtual asphalt mixtures

This paper presents a set of algorithms for creating realistic three-dimensional (3D) models of asphalt mixtures based on its composition. The process begins by measuring the shape of the aggregates in the asphalt mixture. Using these measurements, an algorithm creates 3D volumes that approximate the size and shape of the aggregates. These volumes are then added to a virtual mixer in the same proportions as the aggregates in the real mixture and are pressed together until the air void content of the 3D model matches that of the real asphalt. This results in realistic models of aggregate skeletons in the asphalt mixture. Next, sections are taken from the aggregate skeletons and a mortar mixture, made up of bitumen, filler and fine aggregates, is applied to the sections. Geometrical rules are used to determine which areas of the sections are covered in mortar and which are air voids. The validation of virtual aggregates and air voids has demonstrated good correlations with actual ones. The resulting models are highly realistic and can be used to predict the mechanical or physical properties of asphalt mixtures in future studies.

Pengaruh Penambahan Variasi Abu Tempurung Kelapa Terhadap Karakteristik Mortar

Awareness of the importance of sustainable construction practices and research to explore alternative materials or waste that can be recovered to reduce material use and waste. This was done to evaluate coconut shell ash waste as a partial additive to cement in mortar mixtures. The research carried out aimed to determine the results of the influence of coconut shell ash waste on the absorption value to obtain overall analysis results on mortar mixtures using coconut shell ash additives with variations of 0%, 2.5%, 5%, 7.5%, 10%. The results obtained on the effect of adding coconut shell ash on the water absorption value show that a mixture of coconut shell ash can make mortar lose water more easily when compared to normal mortar, namely with the highest water absorption value of 9.307% in a mixture of 10% coconut shell ash.

Co-grinding treatment for developing integrated-properties SCMs from basic oxygen furnace slag and furnace bottom ash: A step toward synthesis advanced SCMs

The recycling of the basic oxygen furnace slag (BOF) and the furnace bottom ash (FBA) as supplementary cementitious materials (SCMs) will contribute to achieving the sustainability requirements of the infrastructure sector. The BOF possesses inherent hydraulic properties due to its high content of glass network-modifying phases (e.g., CaO, MgO, Na2O, and K2O). However, its poor grindability, variability in quality, and purity are factors that may limit its reuse as a SCM. This paper aims to explore the impact of co-grinding BOF with FBA on the chemical, physical, and microscopic properties of the new combinations and their effect on the performance of their designed mortar. Combinations consisting of three ratios of BOF to FBA (3:1, 3:2, and 1:1) were synthesized, and the results of the co-grinding were compared with those equivalents in separate grinding. The findings indicate that co-grinding improved the fineness and synergies of the BOF-FBA particles without significantly altering the crystalline phases or developing new ones compared to the original materials. Combined grinding had a positive effect on the flowability of mortar mixtures and the development of compressive strength at all curing ages. Microstructural analyses revealed denser and more compact microstructures in mortar designed from the co-ground BOF-FBA combinations, along with lower Ca/Si and Si/Al ratios, indicating the positive influence of co-grinding on the growth of hydrates.

Strength, carbon emissions, and sorptivity behavior of cement paste and mortar containing thermally activated clay

The detrimental impact of anthropogenic gases such as carbon dioxide, methane, and nitrous oxide has become a pressing concern across various industries. In this study, thermally activated clay (TAC) was investigated as a substitute for Portland cement in proportions ranging from 10 to 40 wt%. Compressive strength and efficiency factors were employed to ascertain the optimal mortar mixture. Both the control mortar and the optimal blend underwent capillary water sorptivity tests. Fourier Transformed Infrared spectroscopy (FT-IR) was utilized to gain insight into the hydration process and pozzolanic reaction within the mortar mixtures. Furthermore, the study assessed the impact of the optimized blended mortar on greenhouse gas emissions through estimated carbon dioxide equivalent values. Results revealed that incorporating 30% TAC attained the maximum strength of approximately 33, 36, and 48 MPa at 3, 7, and 28 days respectively compared with the other mortars. The mortar containing 30% TAC enhances both compressive strength and efficiency factors, demonstrating effective pozzolanic activity and minimal compromise on performance. Notably, the inclusion of 30% TAC also led to reduced water absorption rates, indicating improved durability-related performance. Additionally, the study uncovered the superior performance of the 30% TAC mix in terms of efficiency factors and carbon savings. FTIR analysis provided novel insights into the hydration and pozzolanic reactions induced by TAC, resulting in the formation of compounds contributing to enhanced compressive strength over time. This research advocates for the substitution of Portland cement with TAC as a low-carbon binder alternative to traditional Portland cement binders.

Influence of the recycled sand on the cement mortars

In construction, a recent direction is to examine and integrate alternative sources of building materials with the goal of substituting the use of natural materials. This transition is encouraged by growing concern among policymakers and researchers regarding the environmental footprint of the construction industry. The incorporation of recycled aggregates into cementitious materials, such as concrete or mortar, results in a deterioration of their mechanical performance and their durability. Scientific studies devoted to recycled concrete have demonstrated that it is affected by the introduction of these recycled aggregates, in particular by the use of recycled sand. The latter is characterized by the presence of significant proportions of hardened cement, particularly that coming from a recycling plant. In this work, we aim to study experimentally the influence of the nature of recycled sand on the properties of cement mortars, substituting natural sand, with different percentages by volume: 0, 15, 30, 40, 50 and 75 %, by two types of recycled sand, one from the crushing of structural concrete and the other from a recycling plant. The mortar mixtures were made from CEM I 52.5 and Sand/Cement ratio = 3. The plasticity of these mortars was kept constant and the recycled sands have been pre-wetted. The comparative study between the different compositions of recycled mortars has shown that the physical and mechanical properties are influenced by the incorporation rate of the recycled sand. Of which, increases in the compressive strengths of recycled mortars were recorded, particularly those based on sand from the crushing of structural concrete, compared to the control mortar based on natural river sand. However, the flexural strengths of the recycled mortars suffered a slight reduction compared to the reference mortar.

Acceleration of Early Strength Development in Mortars Containing Soluble Silica Extracted from Palm Oil Clinker

Soluble silica from palm oil clinker was extracted using Laine’s method. It involved two major steps, namely water reflux and distillation. The use of 480 g of POCP and 12 hours of distillation in the extraction experiment resulted in 53.50% of dissolved silica, which was the highest gain among the trial experiments and was chosen as an optimum parameter for the subsequent characterisation analysis. In addition, its effect on cement hydration was studied by including it as a filler in mortar mixtures. Mortar with 7.50% of extracted silica gained high strength in the early days of curing and performed well throughout the maturing age. The rapid hardening properties of soluble silica-based mortar would promote the potential of soluble silica as an additive for rapid hardening.

Use of synthetic calcium hydrosilicate in Portland cement compositions

We investigated the patterns of the synthesis of calcium hydrosilicate of tobermorite composition in the "amorphous silica–calcium hydroxide–water" system. The gradual interaction of calcium hydroxide and amorphous silicon(IV) oxide leading to the formation of synthetic tobermorite was confirmed by X-ray diffraction analysis. It was determined that the optimal duration of the synthesis of calcium hydrosilicate was 5 days, which, according to electron microscopic studies, ensured the production of grains with a size of 0.4–4 m. The influence of the synthesized tobermorite on the change in strength characteristics of cement stone during setting was studied using cement-sand mortar mixtures with sands of different particle size distribution. A comparative analysis of the effect of storage conditions of the synthesized product on the structure-forming processes of cement stone was carried out. It was established that the modifying effect of synthetic tobermorite was observed when it was dried after synthesis and stored in a dry state. Conversely, prolonged storage of calcium hydrosilicate in a wet state led to a loss of its activity and a decrease in the strength characteristics of cement stone. The mechanism of the influence of calcium hydrosilicate additive was studied by measuring the change in the rate of heat release of cement dough at the initial stage of hydration. It was shown that the addition of dry calcium hydrosilicate accelerated the physicochemical processes of hydration of clinker minerals, while the addition stored in wet conditions slowed down hydration. Electron microscopic studies of cement stone after 28 days of setting confirmed that the introduction of dry calcium hydrosilicate contributed to the formation of a structure characterized by a higher degree of crystallization and an increase in the strength of the samples.

Sludge-derived biochar as an additive in cement mortar: Mechanical strength and life cycle assessment (LCA)

Given the growing concern about environmental contamination risks, the management of sewage sludge (SS) from wastewater treatment plants is becoming more challenging. Thus, alternative pathways that offer value-added opportunities with minimal environmental impacts are needed. This study investigates the use of 0.52 wt% biochar (BC) powders generated from the pyrolysis of the SS in an N2 or CO2 environment, as an additive in cement mortar mixtures. The effect of dry and pre-wetted BC on the fresh properties, phase formation, compressive and tensile strength properties of cement mortar mixtures were assessed. Thereafter, life cycle assessment (LCA) of Plain and BC-modified mortar mixtures were evaluated, and the environmental impacts arising thereof were quantified. Results showed that whereas the BC had an infinitesimal effect on mix fresh properties, it caused approximately 1734% and 10–18% increases in compressive and tensile strength, respectively. Regardless of the pyrolysis condition, pre-wetted BC had a superior impact on mechanical strength evolution. LCA results showed that except for minor, net increases in particulate matter/water consumption potential, the rest of the impact categories associated with the production of 1 m3 of cement mortar decreased with the addition of the BC. In terms of Global Warming Potential (GWP) per unit 28d compressive strength, the BC-modified mixtures yielded values that were lower than that of the Plain mortar by about 1629%. Therefore, these research findings indicate that the use of SS-derived BC as a low-dose additive in cement composites could help the construction industry mitigate its negative environmental footprints.

Effects of elevated temperatures and cooling regimes on the waste andesite dust-based geopolymer mortars

In this study, the geopolymer mortar mixtures were manufactured by activating andesite stone cutting waste dust with sodium silicate. The sodium silicate content in the mixtures was determined to contain 6%, 8% and 10% Na2O by weight of waste andesite dust (WAD). The produced mixtures were subjected to thermal curing at three different temperatures (60 ºC, 75 ºC and 90 ºC), and in two different periods (8 hours and 24 hours). Flexural strength (fs) and compressive strength (fc) tests of 1, 28 and 56 days were carried out on the specimens obtained from the geopolymer mortar mixtures. The effects of Na2O content, thermal curing temperature and time on the strength values of the geopolymer mortars were investigated. Moreover, the geopolymer mortar samples produced with 8 hours of thermal curing were exposed separately to 400 ºC, 600 ºC and 800 ºC. The specimens, which were kept for 1 hour at 400 ºC, 600 ºC and 800 ºC, were exposed to three different cooling conditions (slow-cooled in air, fast-cooled in air and water-cooled). The fs and fc tests were carried out on the cooled geopolymer mortars, and the effects of high temperatures and cooling conditions on the strength properties of the geopolymer mortars were evaluated. In addition, the changes in the microstructures were examined by performing XRD and SEM/EDAX analyses on the selected geopolymer mortars. The fs and fc values of the water-cooled geopolymer mortars significantly decreased.

Shrinkage cracking and mechanical properties of cementitious composites produced with multiwall carbon nano tubes and different types of polypropylene fibres

This study was conducted to experimentally demonstrate the control the nano-, micro- and macro-scale cracking in cement-based composites by using nano-, micro- and macro-scale fibres. While micro, macro and hybrid system polypropylene (PP) fibres were used in concrete designs, micro-scale PP and multi-walled carbon nano tubes (MWCNT) were utilized in mortar mixtures. The progression of the cracks was monitored in accordance with a well-known standard and also with a modified method which enabled the investigation of plastic and restrained shrinkage. Fracture energy, flexural strength, compressive strength, modulus of elasticity and ultrasonic pulse velocity of the samples were also determined as the mechanical properties of the composites. Results showed significant improvements in the reduction of cracks, especially with hybrid fibres system.

Environmental – Solar thermal effects a long-term on the efficiency of amorphous climate-resilient mortar using a central composite design application

The objective of this investigation is to evaluate the durability of dune sand mortar containing display e-glass waste (DEGW) in severe Saharan environments, chemical attacks, or other factors that can cause cementitious materials to deteriorate at long- term. The aim is to use DEGW powder as a partial replacement for dune sand in various mortar mixtures and assess the performance of hardened mortar in terms of ultrasonic pulse velocity, dynamic elasticity modulus, compressive strength, and flexural strength and sportivity. The study also examines the influence of the curing period and different climatic conditions in curing environments, such as those in Algeria's Sahara region. The Response Surface Methodology (RSM) was used to adjust the e-waste glassy mortar, with the statistical tool Central Composite Design (CCD) approach. The hydration of cement compounds was monitored using differential thermal analysis (DTA), thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), and X-ray diffraction (XRD). The DEGW was replaced in 5% increments from 0% to 20%. The results showed that the glassy dune sand mortar exhibited the highest properties at 20% incorporation after 365 days of severe climatic conditions. The feasibility of the proposed quadratic model was recommended for the five responses by RSM, in which the coefficient of determination (R2) ranges from 0.93 to 0.97, showing the model’s high significance. For structural display e-glassy dune sand mortar, display glass E-waste can replace 20% of dune sand, which improves all durability and environmental sustainability. Furthermore, the DSC, TGA / DTA results and XRD analysis showed that the < 0.08 mm class exhibited good pozzolanic behaviour, and the specimens significantly improved as curing periods increased.

Experimental investigation into the potential of recycled concrete and waste glass powders for improving the sustainability and performance of cement mortars properties

This comprehensive experimental investigation delves into the world of sustainable mortar mixtures by introducing recycled concrete powder (RP) and waste glass powder (GP) as partial substitutes for conventional Portland cement (OPC). The primary goal is to assess how these substitutions affect the mechanical, physical, and durability characteristics of mortar. RP and GP are individually and jointly incorporated at substitution rates of 10 %, 15 %, and 20 % by weight of cement. The study encompasses a wide range of tests, including compressive and flexural strengths, acid resistance, workability, and microstructural analysis. The study shows that replacing 10 % cement with RP increases mortar compressive strength by 13.28 % after 90 days, and a combination of 15 % GP and RP improves mortar durability against chemical attack. Economic evaluations confirm cost savings exceeding 10 % for all blended mortars compared to OPC. The environmental perspective, explored through a carbon footprint assessment, demonstrates substantial reductions in CO2 emissions when RP and GP are employed in lieu of OPC. Overall, this study highlights the potential of utilizing recycled materials, to enhance the performance and durability of cement-based concrete production.

Evaluation of Hydrothermally Treated Wood Fibre Performance in Cement Mortars

Biofibres’ wide application in mortar enhancement has thus far been restricted by factors related to their chemical composition and hygroscopic nature. Their hydrophilic behaviour increases the water demand of mortar mixtures and diminishes their affinity to the matrix, while further moisture-related fibre degradation issues may arise. Additionally, natural fibres seem to be susceptible to degradation caused by exposure to alkaline environmental conditions such as those experienced by cement mortars, restricting their utilisation in the construction industry. Therefore, the current study investigates the potential of fibre modification through treatments that would permanently alter their structure and chemical composition to improve their performance. In this study, wood fibres of black pine and beech species were exposed to mild thermal treatment (140 °C 2 h, under a steam atmosphere), characterised in terms of the physical and chemical properties and incorporated in cement mortars, applying the proportion of 1.5% v/v in the mortar, in order to assess their performance as reinforcement material. The mortars’ workability (at a fresh state) was examined, as well as other physical, hygroscopic, thermal, and mechanical characteristics of the mortars at the ages of 28, 90 and 365 days and weathering performance, by subjecting them to different artificial ageing environments (freeze–thaw cycles or outdoor exposure). The results revealed the beneficial role of the treated fibres in dimensional stability, flexural strength, thermal insulation properties and capillary absorption of the mortar specimens, especially during the ageing process, with the black pine fibres showing the greatest improvement. The hydrothermally treated wood fibres seem to help maintain the integrity of cement mortars under all ageing conditions, proving that they could provide low-cost and eco-friendly mortar enhancement pathways.

Post-Consumer Carpet Fibers in Concrete: Fiber Behavior in Alkaline Environments and Concrete Durability.

The widespread use of carpets in residential and commercial buildings and their relatively short life span result in large volumes of carpet being landfilled. A potential solution to this problem is the use of post-consumer carpet fibers in concrete. To this end, this paper systematically identifies the common fiber types in a typical post-consumer carpet fiber bale and evaluates their durability under exposure to varying levels of alkalinity. The tensile strengths and toughness of the fibers belonging to the nylon and polyethylene terephthalate (PET) families (the dominant fibers in most post-consumer carpets) are reduced by up to 50% following exposure to extreme alkalinity, the reasons for which are determined using spectroscopic and microscopic evaluations. The chloride ion transport resistance of concretes (~40 MPa strength) containing 2.5% carpet fibers by volume (~25 kg of fibers per cubic meter of concrete) is comparable to that of the control mixture, while mortar mixtures containing the same volume fraction of carpet fibers demonstrate negligible enhancement in expansion and loss of strength when exposed to 1 N NaOH. This study shows that moderate-strength concretes (~40 MPa) for conventional building and infrastructure applications can be proportioned using the chosen volume of carpet fibers without an appreciable loss of performance. Consideration of low volume fractions of carpet fibers in low-to-moderate-strength concretes thus provides a sustainable avenue for the use of these otherwise landfilled materials in construction applications.

Enhancing Mortar Mixtures with Bacterial Impregnation: Sustainable Approaches and Strength Improvement

Enhancing Mortar Mixtures with Bacterial Impregnation: Sustainable Approaches and Strength Improvement

Suitability of Using LA Abrasion Machine for the Nano Manufacturing of Palm Oil Fuel Ash and Incorporating in Mortar Mixture

Background In order to enhance the properties of palm oil fuel ash-based mortar, researchers have explored the concept of reducing palm oil fuel ash (POFA) to a nanoscale. While previous studies have utilized ball milling machines with high grinding speed to achieve nano-scale POFA, the Los Angeles abrasion machine, which is more readily available and has a slower grinding speed, has been rarely employed. Objective The study aimed to investigate the suitability of using a Los Angeles abrasion machine with a low grinding speed to produce nano palm oil fuel ash. This paper also provides a comparison of the effect of using the nano POFA with different particle sizes within the range of 982 to 150 nm on the mortar’s flowability and compressive strength. Methods To produce nano-size palm oil fuel ash using the Los Angeles abrasion machine, the received palm oil fuel ash was thermally treated and ground using a Los Angeles abrasion machine with varying grinding periods. The grinding process parameters were kept constant, but second grinding periods of 50,000, 80,000, and 110,000 cycles were introduced. All three types of nano palm oil fuel ash were analyzed for their physical properties, chemical properties, morphology, and mineralogy. Furthermore, these nano palm oil fuel ashes were incorporated into a designed mortar mix along with micro palm oil fuel ash. The mortar’s fresh properties and compressive strength at different curing ages were observed and analyzed. The relationship between various factors, such as the replacement rate of micro, nano palm oil fuel ash, the grinding cycles of nano POFA, and the corresponding responses, specifically the compressive strength at different curing ages, was analyzed and explained using the response surface methodology. Results The 110k cycle nano palm oil fuel ash had a smaller particle size of 103.1 nm, while a particle size of 529 nm and 325 nm was found in the 50k and 80k cycle nano palm oil fuel ash. In terms of the combination of micro and nano palm oil fuel ash in the mortar, increasing the dosage of nano palm oil fuel ash contributed to improvements in flow diameter and compressive strength. However, the opposite trend was observed with micro palm oil fuel ash. The optimal mix design for the combination involved using 10% micro and 2 to 3% nano palm oil fuel ash. This composition led to an improvement rate of 7.9%, 1.48%, and 4.6% in compressive strength at 7, 28, and 90 days, respectively. While, the response surface methodology’s numerical optimization also supported the use of a similar combination. However, it additionally recommended employing the 50,000-cycle nano palm oil fuel ash in the mortar for earlier curing stages, while the 110,000-cycle nano palm oil fuel ash was suggested for later curing stages. Conclusion Los Angeles abrasion machine could be utilized to produce nano palm oil fuel ash with a particle size up to 103 nm with the aid of designed parameters. In this mortar mix design, the impact of a small variance in nano palm oil fuel ash’s particle size was trivial compared to the replacement rate of micro palm oil fuel ash on the mortar’s compressive strength.