Cement Replacement Rate Research Articles

Investigation of Microstructural Properties of Nano-modified Concrete for Sustainable Environment

The creation and evaluation of Nano-modified concrete, with an emphasis on its microstructural characteristics, is the main goal of this extensive study. The inclusion of nanosilica and nanoclay not only enhances the characteristics of concrete but also contributes to mitigating soil pollution. By adding nanosilica and nanoclay as additional cementitious materials, the study intends to assess the structural integrity of nano-modified concrete using cutting-edge techniques like Scanning electron microscopy, Transition electron microscopy and X-ray diffraction. Four different concrete compositions with variable amounts of nanosilica and nanoclay additions (0%, 5%, 10% and 15% of nano additives by weight of fine aggregate) and a 3% cement replacement rate were cast and evaluated throughout the experimental phase. A comparison with regular concrete revealed significant improvements in microstructures, demonstrating the efficacy of nano-modified concrete without sacrificing necessary characteristics. Slump values increased with the addition of nano-silica and nanoclay, indicating better workability and smoother concrete surfaces. The study's findings indicate that the development of Nano-modified concrete has great potential as an advanced building material. In addition to providing instant structural gains, the use of nanosilica and nanoclay enhances the long-term performance of concrete buildings and creates new opportunities for creative and long-lasting building techniques.

Effectiveness of Carbide Lime Waste as CO<sub>2 </sub>Capturing Materials of Mortar at Early CO<sub>2 </sub>Curing Age

This study explored the use of Carbide Lime Waste (CLW) in mortar production and its exposure to controlled CO2 curing for 24 hours. The results indicate that CLW mortar under CO2 curing has improved compressive strength and early CO2 capturing performance due to the reaction between Ca (OH)2 in CLW and CO2 gas. With a cement replacement rate of 20, a 60% solid carbonates precipitation was recorded after just 7 days of curing. In general, the longer the curing durations, the higher the CO2 capturing capability. Further investigations into the long-term mechanical and durability properties are recommended to assess its feasibility for practical applications. Re-utilization of waste materials like CLW can make significant strides towards more eco-friendly and sustainable practices.

リサイクルセメントを用いた高強度モルタルの圧縮強度に関する基礎的研究

In this study, compressive strength of high strength mortar using cement-based powder extracted from sludge separated from ready-mixed concrete was examined for the purpose of assisting effective treatment of returned concrete. As far as the mortar with a W/B of 30% was compared, the mortar with a high recycled cement replacement rate of over 75% took a longer time to flow down and tended to have a higher viscosity than the other mortars. And, it was found that the compressive strength of mortar using 100% recycled cement was about 0.7 to 0.8 that of mortar using ordinary Portland cement.

Effect of Iron Tailing Powder-Based Ternary Admixture on Acid Corrosion Resistance of Concrete.

Exposure of concrete to acidic environments can cause the degradation of concrete elements and seriously affect the durability of concrete. As solid wastes are produced during industrial activity, ITP (iron tailing powder), FA (fly ash), and LS (lithium slag) can be used as admixtures to produce concrete and improve its workability. This paper focuses on the preparation of concrete using a ternary mineral admixture system consisting of ITP, FA, and LS to investigate the acid erosion resistance of concrete in acetic acid solution at different cement replacement rates and different water-binder ratios. The tests were performed by compressive strength analysis, mass analysis, apparent deterioration analysis, and microstructure analysis by mercury intrusion porosimetry and scanning electron microscopy. The results show that when the water-binder ratio is certain and the cement replacement rate is greater than 16%; especially at 20%, the concrete shows strong resistance to acid erosion; when the cement replacement rate is certain and the water-binder ratio is less than 0.47; especially at 0.42, the concrete shows strong resistance to acid erosion. Microstructural analysis shows that the ternary mineral admixture system composed of ITP, FA, and LS promotes the formation of hydration products such as C-S-H and AFt, improves the compactness and compressive strength of concrete, and reduces the connected porosity of concrete, which can obtain good overall performance. In general, concrete prepared with a ternary mineral admixture system consisting of ITP, FA, and LS has better acid erosion resistance than ordinary concrete. The use of different kinds of solid waste powder to replace cement can effectively reduce carbon emissions and protect the environment.

Test research on the effect of waste ceramic polishing powder on the compressive strength and chloride penetration resistance of seawater concrete

Waste ceramic polishing powder (CPP) is a by-product created during the grinding and polishing process of the ceramic industry, which adversely affects the environment. In this research, it was used as auxiliary material to partially replace cement during the casting of the test specimens. The effect of cement substitution by 0%, 5%, 10%, 20%, 30%, 40% and 50% of the CPP with seawater and freshwater mixing on the compressive strength and resistance to chloride penetration of the concrete is compared. Moreover, the microstructure development and hydration products of both pastes are determined by different methods. Experimental results show that the compressive strength and resistance to chloride penetration of concrete samples, with the CPP and seawater mixing, is superior to that of the freshwater specimen, with the CPP mixing at the same curing time and the same CPP content. The compressive strength of both types of concrete tends to decrease with increasing content of CPP replacing cement. The compressive strength of concrete meets design requirements when the rate of cement replacement is up to 30% of CPP content when mixed with seawater, but the compressive strength of concrete meets design requirements when the rate of substitution cement reaches a maximum of 10 wt% CPP content mixed with freshwater. In contrast, the resistance to chloride penetration of both types of concrete mixed with CPP is better than that of the specimen without CPP and with the increase of cement replacement rate with CPP, the chloride resistance of concrete shows a rising trend. Under the same CPP substitution and the same curing time, the resistance of chloride penetration of concrete with freshwater mixing is lower than that of concrete mixed with seawater. In addition, the main hydration products in freshwater and seawater pastes with that CPP mixing were CH, ettringite and CSH. In particular, the component of the CPP promoted the formation of Friedel’s salt in concrete mixed with seawater. Seawater increased CH content at an early age (7 days) and decreased later (28 days). At a later age, most of the chlorides in seawater with that CPP component were immobilized by hydrocalumite, which microstructure became denser and compacted structure of concrete.

Mechanical properties and hydration of ultra-high-performance seawater sea-sand concrete (UHPSSC) with limestone calcined clay cement (LC3)

Ultra-high-performance seawater sea-sand concrete (UHPSSC) has attracted increasing attentions over the past few years as it exhibits exceptional mechanical and durability properties similar to conventional ultra-high-performance concrete (UHPC). Comparing to conventional UHPC, UHPSSC has great advantages when applied in marine engineering, particularly in offshore projects where construction materials are not easily accessible, and the transportation is costly. Nonetheless, current production of UHPSSC still necessitates large amounts of cement due to its low water/binder ratio. The larger demands of cement in manufacturing UHPSSC/UHPC than ordinary concrete can lead to substantial increase in the carbon emission. Therefore, an eco-friendly UHPSSC is developed in this paper by incorporating a promising ternary binder system (LC3) that consists of limestone (LS), calcined clay (metakaolin) and cement. The influence of the metakaolin (MK) dosage on the mechanical, hydration and microstructure properties of UHPSSC is comprehensively studied by carrying out a variety of experiments including mechanical test, isothermal conduction calorimetry test, TGA, XRD, SEM etc. The results showed that the UHPSSC mixed with LC3 exhibited lower early-age compressive strength than the reference mix, but its long-term strength was better than the reference group owing to the formation of more hydrates at the late age by the pozzolanic reaction of MK and the synergistic reaction between LS, MK and cement. Based on this study, the coupled replacement rate of cement by LS and MK could reach up to 40% without strength compromise. Nonetheless, 20% MK and 10% LS appeared to be the optimum substitution rate (total substitution rate of 30%) where the highest long-term strength was achieved. The main exothermic peak and total heat of hydration normalized per binder weight decreased with the increase of MK content level, but the main peak occurred earlier. Moreover, the addition of seawater can promote the hydration, leading to a greater main exothermic peak.

Assessment of Sieving as a Mean to Increase Utilization Rate of Biomass Fly Ash in Cement-Based Composites

Biomass fly ash is a growing challenge for combustion by-product (CBP) management. This research was conducted to investigate the influence of activation by sieving through a 63 µm sieve and a 125 µm sieve on fresh and hardened cement mortar properties. Sieving increased the CaO content by 9.3 percentage points (p.p.) in the oxide composition of the fly ash. The 28-day Strength Activity Indices increased by 24.9 p.p. A 25% replacement rate of cement with fly ash sieved with a 63 µm sieve increased the 2-day compressive strength of mortars by 24% when compared with untreated fly ash. The 90-day compressive strength results of cement mortars with a 15% replacement rate of cement with fly ash sieved with a 63 µm sieve were similar to the control specimen results. The utilization rate of biomass fly ash can be increased to 15% of binder mass without the detrimental effect of the mechanical properties of cement mortar. SEM and TG analyses showed that activated biomass fly ash promoted the growth of the C-S-H phase and ettringite.

A study on properties, static and dynamic elastic modulus of recycled concrete under the influence of modified fly ash

The effects of modified fly ash (MFA) on the replacement rate of cement, the quality and replacement rate of recycled fine aggregates (RFA), the mechanical properties of concrete, such as compressive strength (fc), static elastic modulus (Ec), dynamic elastic modulus (Ed), and durability, i.e., drying shrinkage (ε), were investigated in this study. Based on the data and discussion of the results, different linear correlations were found between Ec and Ed, and the concrete’s age was found to be an important influencing factor. A new equation about Ec and fc of concrete was proposed, as well as the relationship between Ed and fc, and the correlation coefficients were analyzed by the quality and substitution of recycled fine aggregates, and it was confirmed that they were two important influencing factors. Finally, the correlation between Ed and ε and the pore volume in the pore diameter interval of concrete was investigated under the influence of the quality and replacement rate of aggregates and the replacement rate of MFA, and it was found that the variation of Ed and ε on the pore volume correlation coefficient was highly consistent.

Application of powdered bio-composites in the field of self-compacting concrete: A review

Cement manufacture accounts for 5% of worldwide carbon dioxide emissions, resulting in significant environmental issues, and using supplemental cementitious materials (SCM) is an efficient strategy to minimise cement consumption. Self-compacting concrete (SCC) often relies on high amounts of binder and chemical additives to maintain workability. Thus, reducing the embodied carbon of SCC materials becomes essential for its wider application. Powdered bio-composites (PBCs), such as rice husk ash (RHA), bagasse ash (BA), palm oil fuel ash (POFA), groundnut shell ash (GSA), and eggshell ash (ESA), can be utilised as SCM for SCC. This paper systematically reviewed the physical properties, chemical properties, and heat treatment methods of five types of PBCs and their impacts after replacing cement in SCC. The review disclosed that heat treatment could effectively reduce the value of loss on ignition (LOI), thus ensuring the activity of PBCs. High-temperature, short-duration incineration or low-temperature incineration for a long time can be effective. The review revealed that adding the five types of PBCs will reduce the workability of SCC, and RHA has the greatest negative impact. Segregation occurs when the cement replacement rate with RHA exceeds 20%. All five types of PBCs improve the mechanical properties of SCC to a certain extent after replacement. The preferred replacement rates are 5%-20% for RHA, BA and GSA, while for POFA the preferred rate could exceed 30%. The preferred rate is not conclusive for Eggshell ash, as it may lead to either positive or slightly negative impacts regarding compressive strength. In addition, adding an appropriate amount of PBCs will increase the durability of hardened SCC. The summarised impacts were also correlated with the microstructure of SCC through various analysis tools. The paper reveals the current gaps in applying PBCs in SCC and proposes strategies to design environmentally friendly SCC containing PBCs.

Early Age Monitoring of High Cement Replacement Mixtures for Pavement

Decarbonization of concrete will require a combination of alternative binding materials and higher cement replacement rate with supplementary cementitious materials. Developing tools and methods that help engineers evaluate the properties of early age concrete pavement, such as setting time and strength gain, will be necessary to adopt new concrete mixes. Two concrete pavement test sections were constructed, a high early strength concrete mix with 25% (control) and 40% replacement of cement with fly ash (HVFAC), along with monitoring of the concrete’s setting time, saw-cut timing, and strength gain. A non-contact ultrasonic device was used to estimate setting time through measuring leaky Rayleigh wave energy transmission. The laboratory setting time of the control and HVFAC mix measured with the non-contact device was 5.5 h and 15 h, respectively, and agreed with measured isothermal calorimetry results. Further calorimeter tests showed that adding an accelerating admixture or replacing part of the cement with nano-limestone decreased the HVFAC setting time up to 4.4 h. The field setting time of the control mixture with the non-contact device measured 4.2 h, which was shorter than the laboratory estimate. Based only on the experience of construction personnel, saw-cutting for these mixtures was initiated too early and caused significant joint raveling, reinforcing the importance of in situ setting time measurement. The maturity method was successfully implemented with embedded wireless temperature sensors that rapidly and easily estimated the in-place compressive strength and improved opening time determination for concrete with high cement replacement levels, which are sensitive to the volume of supplementary cementitious materials, admixtures, and ambient conditions.

Durability aspects and mechanical strength of mortars containing glass powder and slag

The combination of glass powder (GP) with pozzolanic additions to replace clinker can develop new types of binders (ternary cement) with improved physical and mechanical properties, thereby enabling a reduction in consumption of clinker and natural resources, and the minimisation of the carbon dioxide emissions. In this context, the present work is an attempt to study the influence of GP with two different specific surface areas (Blaine) GP30 = 300 m2/kg and GP45 = 450 m2/kg, combined with slag, on the mechanical behaviour and durability of mortars. The mechanical properties were investigated using compressive and flexural strength tests. Aspects related to durability were examined as well by water-accessible porosity, capillary absorption and sorptivity tests. The replacement rate of cement by GP varied from 10 to 20% and the proportion of slag was fixed at 10%. The results showed that a binary mortar made with 20% GP45 replacement showed increases in 90 day compressive strength, while ternary mortar with 20% GP45 + 10% slag replacement gave the best result. The same trend is also valid for durability properties examined in this study. The combined use of GP and slag at 30% replacement levels seemed to perform better compared with using GP alone.

The effect of calcination conditions on oat husk ash pozzolanic activity

Supplementary cementitious materials (SCMs) are known and used to reduce cement consumption, but some waste sources currently used for partial cement replacement are threatened by changing industrial production processes and local availability. Thus, considering possible sources of amorphous silica for use as SCM, especially pozzolans, there is an opportunity to investigate the use of agricultural residues such as oat husks, which currently have little or no commercial value. This work aims (i) to identify the burning temperature that promotes the reduction of carbon content and increase the amorphous material, (ii) to present the chemical and physical characterization analysis results, and (iii) to evaluate the pozzolanic potential of selected oats husks ashes (OHA) produced under controlled calcination temperatures. Local samples of oat husks were sun-dried, sieved, and split into two portions. One portion was subjected to analysis of moisture content, and the second portion was pre-calcined at 350 °C for 2 h in an aerated laboratory oven and turned into ashes under 400 to 700 °C respectively, using ramp heating rate of 10 °C/min. The ashes were ground in a ball mill and subjected to chemical and physical analysis, considering Loss on Ignition (LOI) at 950 °C, chemical composition through Energy Dispersive X-Ray Analysis (EDX), structural state analysis by X-ray diffraction (XRD), morphology by digital microscopy, density using glass pycnometer and chemical reactivity with calcium hydroxide measured through thermogravimetric analysis of a control mortar defined as (R3) model paste. The results show that the ash chosen for pozzolanic potential analysis, produced at 600 °C, shows an average ash content value of 3.6%, and chemical concentration of 45.97% oxygen (O), 21.2% silicon (Si), and 16.91% potassium (P), in addition to evidence that characterizes crystallization of its structure and consumption of 8.74% of Ca(OH)2 from the control matrix, indicating low pozzolanic activity. It was concluded that local oat husks in Ireland calcinated between 600 and 700 °C presented a favorable balance between the percentage of residual carbon amount and silica in the amorphous form that is favorable to react with calcium hydroxide forming calcium silicate hydrate. It opens up a possibility of investigating the use of OHA as SCM, requiring more studies about the oats husks calcination time, cement replacement rate, and performance tests to consider practical applications, and maybe contributing to reducing the OPC consumption, production necessity, and consequently, the environmental issue caused by its production.

The impact of alkali activator dosage on the compressive strength and water absorption of steel slag concrete

Steel Slag (SS) is an alternative for cement replacement in concrete. However, high replacement rate of SS increases the workability of concrete at the same time reduces the early strength of concrete. The aim of this study is to investigate the effect of different dosage of alkali activator in concrete with 40% SS as cement replacement on its workability, compressive strength, and water absorption. In this study, different dosage of Na2SO4 were added into SS based concrete with fixed cement replacement rate at 40%. Result shows that the workability of SS based concrete decreased with the increase of Na2SO4 dosage. The early strength increases with the addition of Na2SO4 from 1 to 3% and decreased over 3%. The 28-day and 90-day strength increase with the addition of Na2SO4 from 1 to 4% and decrease over 4%. The rate of water absorption of SS based concrete reduced significantly with the increase of Na2SO4. From the experimental result, it is observed that the addition of 4% Na2SO4 gives the highest strength of 35.12 MPa at 28-day.

Strength and flexural behavior of steel fiber and silica fume incorporated self-compacting concrete

Self-Compacting Concrete (SCC) that flows by its own weights without compaction or vibration, thereby no external energy from mechanical equipment. In addition to this, cement replacement with silica fume and the introduction of steel fibers have allowed the improvements in durability and hardened properties of SCC. These materials are very important to prevent segregation, bleeding, and increase flow-ability. However, the addition of fibers to SCC may lead to a decline in the workability but in other way helps to improve hardened concrete properties. This paper discusses the results of an experimental investigation onto fresh and hardened properties of the self-compacting concrete mixes with four different percentages of steel fibers (0.25, 0.50, 0.75, and 1.0%) and 20% cement replacement rate with silica fume was incorporated. The workability of fresh concrete was assessed using three tests (slump flow, slump flow T50, L-box, and V-funnel tests) according to EFNARC specification and one visual test (segregation resistance) as per ASTM C 1611. The results showed that using fibers layers led to reduced workability with improved hardened concrete properties, especially toughness. However, the improved tensile and flexural toughness in SCC counteract the reduction in workability. The toughness tests are compared by introducing quadruplicate patterns containing four layers (each layer is 25 mm height) and having seven combinations of fiber laying patterns to quantify the impact in prism specimens. The quadruplicate patterns of steel fibers provide good predictions of impacts of fiber orientation on hardened properties of concrete. The results of this study indicate that the use of silica fume as a replacement for cement and incorporation of steel fiber produces more economically feasible and durable SCC.

Efficiency of cement content and of compactness on mechanical performance of low cement concrete designed with packing optimization

The unavoidable concern with developing sustainable materials in the construction sector has led to the attempts to reduce the content of Portland cement in structural concrete mixtures. Thus, the main objective of this research was to develop low cement concrete (LCC), maximizing the replacement rate of cement by additions and/or reducing the amount of binder through combining the design parameters of concrete, such as water/cement, water/binder, and compactness, without compromising the specified mechanical performance and consistency. The mix-design and characterization of various LCC mixtures were developed, considering two amounts of powder in the binder paste, 350 and 250 kg/m3, being the first with very plastic consistency and the latter with dry consistency and low cohesion, due to the reduced proportion of water and binder. These were combined with large spectrum of cement replacement rates, through adding fly ash and limestone filler, as well as with different compactness levels, and with the variation of aggregates proportions. The concrete mixtures were characterized in fresh and hardened states, in terms of consistency, compressive, tensile and flexural strengths and the Young’s modulus.Results revealed that a lower amount of powder in the binder paste leads to lower consistency and cohesion. However, it is possible to improve the workability if a powder content up to 350 kg/m3 is adopted. Thanks to the optimized combination of Portland cement, fly ash and limestone filler additions, and the granulometric optimization and the use of superplasticizer, it is possible to produce LCC with good workability, stability, and mechanical performances, thus mitigating the limitation of using high content of fly ash as partial substitute for cement. The characterization of the mechanical strengths and the Young’s modulus revealed that is possible to substantially reduce the Portland cement content of LCC mixtures, up to about 50%, being however possible to increase that replacement rate up to 70%, assuming simultaneously an adequate performance for structural purposes. The variation of aggregates proportioning, which is controlled by different granulometric curves, revealed high influence both on consistency and on Young’s modulus.

Milling of peat-wood fly ash: Effect on water demand of mortar and rheology of cement paste

The milling of fluidized bed combustion fly ashes is a promising method to improve ashes’ properties as a cement replacement material. Two fly ashes from the co-combustion of peat and wood, as well as inert sand were milled at varying times. The physical properties of materials, water demand of mortar and rheology of cement paste were studied. At 25% cement replacement rate, the milling decreased the water demand of mortar by 10% and the yield stress of cement paste by 33%. It was found that milling disintegrated irregularly shaped particles, which were the main reason for high water demand of ashes, and tapped density could be used as a simple parameter to estimate the water demand for all studied materials.

Rheological study of self-compacting mortars based on ternary cements

Self-compacting concrete (SCC) is able to provide the ability to be easily implemented without vibration and to achieve spectacular structures, by its high fluidity and its rheological stability. By against its formulation requires a large volume of cement, which is necessary to allow its flow. The current environmental considerations lead to reduce the production of clinker however, it is essential to use cementitious additions to replace cement, because of their high availability and their moderate price. Furthermore, their use contributes in a simple and economical way to solve the problems related to the environment. The objective of our work is to study the effects of the incorporation of mineral additions such as: blast furnace slag of El-Hadjar (BFS), and marble powder (MP) on the rheological parameters of selfcompacting mortars developed in different combinations in ternary system with a substitution rate ranging from 20% to 60%. According to this study, it been found that the substitution of cement by blast furnace slag and marble powder has negatively affected the rheological behavior of the mixtures. In addition, a considerable decrease in the rheological parameters has been achieved with a substitution rate of 20% of slag and 30% of marble powder. As well as an improvement of workability has been proven to self-compacting mortars and this is due to the increase of ternary cement replacement rate by marble powder from 20% to 30%.

Rheological study of self-compacting mortars based on ternary cements

Self-compacting concrete (SCC) is able to provide the ability to be easily implemented without vibration and to achieve spectacular structures, by its high fluidity and its rheological stability. By against its formulation requires a large volume of cement, which is necessary to allow its flow. The current environmental considerations lead to reduce the production of clinker however, it is essential to use cementitious additions to replace cement, because of their high availability and their moderate price. Furthermore, their use contributes in a simple and economical way to solve the problems related to the environment. The objective of our work is to study the effects of the incorporation of mineral additions such as: blast furnace slag of El-Hadjar (BFS), and marble powder (MP) on the rheological parameters of selfcompacting mortars developed in different combinations in ternary system with a substitution rate ranging from 20% to 60%. According to this study, it been found that the substitution of cement by blast furnace slag and marble powder has negatively affected the rheological behavior of the mixtures. In addition, a considerable decrease in the rheological parameters has been achieved with a substitution rate of 20% of slag and 30% of marble powder. As well as an improvement of workability has been proven to self-compacting mortars and this is due to the increase of ternary cement replacement rate by marble powder from 20% to 30%.

The Properties of Fine-Aggregate Concrete with Recycled Cement Powder

The main aim of this contribution is verification of properties of concrete with partial replacement of cement by recycled cement powder originating from waste concrete. The main topic of this article is the study of influence of partial replacement of cement by recycled cement powder (RCP) to the cement paste properties, workability of fresh concrete and strength development and dynamic modulus of elasticity of fine aggregate concrete with partial replacement of cement. The workability of fresh concrete were tested by flow table test. The compressive strength, tensile strength in bending and dynamic modulus of elasticity were tested at the age 7, 14, 28 and 90 days. Partial replacement of cement was 0, 5, 10 and 15 % for all these tests. Mechanical properties were investigated by using cubic and prismatic specimens. The determination of the initial setting time of cement paste were measured by automatic Vicat apparatus for replacement rate of cement 0, 5, 10, 15 and 25 %.

Role of Filler Effect and Pozzolanic Reaction of Biomass Ashes on Hydrated Phase and Pore Size Distribution of Blended Cement Paste

The role of filler effect and pozzolanic reaction of biomass ash on hydrated phase and pore size distribution of blended cement paste was studied. Rice husk ash (RHA), palm oil fuel ash (POFA), and river sand (RS) were ground to two fineness values, and used to replace Type I portland cement (OPC) at 0, 20, and 40% by weight of binder. A water to binder ratio of 0.35 was used. The compressive strength, pore size distribution, and thermogravimetric analyses of the blended cement pastes were investigated. Partial replacement of OPC with fine RHA and POFA at a dosage of 20% by weight of binder resulted in pastes with higher compressive strengths than that of OPC paste. The compressive strengths of RHA paste were slightly higher than those of POFA pastes at the same age. The differences between mass losses (at 30–450°C) of RS and RHA (or POFA) blended pastes at the same fineness, curing time, and replacement rate were due to the pozzolanic reaction, which increased in accordance with particle fineness and cement replacement rate. In addition, the weight losses (at 30–450°C) due to the pozzolanic reaction were higher than those due to the filler effect. The use of fine RHA and POFA enhanced the pozzolanic reaction, and reduced the average pore diameters of pastes.