Compressive Strength Of Cement Mortar Research Articles

Feasibility study of replacing part of cement by igneous rock powder as cementitious material: based on mortar macroscopic properties and microstructure

To address the increasing demand for cement and promote sustainable development, the utilization of igneous rock powder as a supplementary material to partially replace cement has emerged as an effective strategy. In this study, the fluidity and mechanical properties of the igneous rock powder-cement (IRP-OPC) composite system were investigated, and the hydration product and microstructure of IRP-OPC were analyzed by using TG/DSC, N2 adsorption-desorption curve (BET) and SEM. The experimental findings demonstrate that the performance of the andesite powder-cement composite cementing system (AP-OPC) surpasses that of tuff powder-cement slurry (TP-OPC) and granite powder-cement slurry (GP-OPC). When the dosage of andesite powder (AP) is 5%–15%, the flowability, flexural strength and compressive strength of cement mortar are improved. When the dosage is 10%, the 28-day compressive strength is 48.3 MPa. Under the condition of low content (10%), part of Ca(OH)2 is fully consumed by active SiO2 in AP and reacts to form C-S-H. Hydration products and AP particles with small particle size are filled into the structural gap, which refines the pore structure of cement slurry, and the increase in compactness provides support for the development of strength in the later stage. The use of 5%–15% AP instead of OPC can improve fluidity and meet the strength requirements of P.O 42.5 Portland cement. This substitution not only reduces engineering costs but also enhances resource utilization.

Experimental Study on Compressive Strength of the Cement Mortar Cubes with Partial Replacement of Fine Aggregate Using Polyvinyl Chloride (PVC) Plastic

Mortar is a material that consists of cement and sand with a range of applications in the construction industry. However, the plain mortar materials are usually brittle and often crack and fail more suddenly than reinforced mortar. This experimental study is about the compressive strength of cement mortar stabilised with the use of the polyvinyl chloride (PVC) plastic powder. Generally the compressive strength of cement mortar of mix proportion (1:3) is 33 N/mm² to 53 N/mm² has been obtained after 28 days curing. The cement mortar ratio is 1: 3 respectively. The PVC powder is added along with the sand with percentages of 0%, 2.5%, 5%, 7.5%, 10% respectively. And the water cement ratio is 0.5 with volume. The moulds of 70×70×70 mm size were used for the cube test, and the cubes were tested on the Compressive testing machine to determine the strength of cube for 3, 7, 28 days of time period respectively. The main aim of f this study to determine the compressive strength of cement mortar (1:3) of sand added with PVC powder, Key Words:- Waste Plastic, Polyvinyl Chloride, Compressive Strength, Mortar.

Effects of reactive MgO on durability and microstructure of cement-based materials: Considering carbonation and pH value

Reactive MgO is a type of eco-friendly material with a lower carbon footprint, as it is produced by calcination of magnesite (MgCO3) at 750 ℃, much less than that (i.e. 1450℃) needed for calcination of (CaCO3) to produce clinker for Portland cement. Carbonation can enhance the mechanical properties of reactive MgO-based cementitious materials but will lower the pH value, leading to the neutralization of cement-based materials and further deterioration in rebar passivation. In this study, varying amounts of reactive MgO (0%, 10%, 20%, and 30%) were incorporated into mortars as cement replacements. By adjusting the duration of CO2 curing (i.e. carbonation curing) and standard curing, it was found that the curing regime involving 36 hours of carbonation curing plus 26.5 days of standard curing led to a higher pH and compressive strength of cement mortars. The pore size distribution was improved as the internal pores of the mortar were filled with carbonation products, which hindered the reaction between CO2 and alkaline hydration products inside specimens and was conducive to maintaining the alkalinity within the mortar. Therefore, the chloride ion penetration resistance and the mechanical properties of mortar were enhanced. SEM and EDS characterization results indicate that the excessive MgO did not fully participate in carbonation and continuously hydrated to generate Mg(OH)2. The expansion of Mg(OH)2 led to crack formation inside the mortar and reduced its strength, which accelerated CO2 diffusion and further reduced the pH value of reactive MgO-based cementitious materials.

Cement Mortars Based on Polyamide Waste Modified with Fly Ash from Biomass Combustion—A New Material for Sustainable Construction

The article presents an analysis of the possibility of using the waste of polyamide 6 modified with fly ash (in the amount of 5, 10 and 15%) from the burning of wood–palm kernel shells biomass as an addition to cement mortar. Fly ash from the burning of biomass in a circulating fluidized bed boiler (which currently has no practical use) was first used to produce polyamide 6, and then post-production polymer waste (added at 20, 40 and 60%) was used to produce ecological mortar. The use of this type of waste is both economically profitable and desirable due to the need to implement waste material management processes in a closed circuit. The addition of polyamide 6 waste containing 5% fly ash in amounts of 20 and 40% and waste containing 10% ash in 20% to cement mortars improves their mechanical properties. The compressive strength of cement mortars (after 28 days of maturation) containing 20 and 40% of polyamide waste containing 5% fly ash increases by 6.6 and 4.6%, respectively, and the flexural strength by 4.9 and 3.4% compared to the control mortars. However, the compressive strength of mortars with the addition of 20% polyamide waste containing 10% fly ash increases by 4.2% and the flexural strength by 3.7%. Cement mortars modified with waste are characterized by slightly lower water absorption and mechanical strength after the freezing–thawing process (frost resistance) compared to control mortars and do not have an adverse effect on the environment in terms of leaching metal ions.

Polydopamine: A novel high-efficiency accelerator for Portland cement

This study develops a novel accelerator with dopamine for rapid setting of shotcrete. Based on the oxidative self-polymerization, the dopamine reacts with O2 to produce polydopamine (PDA) in the agitation process of cement paste. The as-prepared PDA facilitates the generation of ettringite. Additionally, it controls ettringite to nucleate and grow on the surfaces of various clinkers, which decreases the negative effect of surface-bound hydrate on the dissolution of C3A. As a result, with 0.10% dosage of dopamine, the initial setting time of cement paste is shortened from 118 min 45 s to 3 min 38 s, and the final setting time is shortened from 212 min 45 s to 11 min 8 s. This dosage is much lower than those achieved by any hitherto-reported materials. Besides, the compressive strength of cement mortar reaches 33.6 Mpa in 28 days, which can meet the requirements of building engineering.

Effect of Silica Fume Concentration and Water–Cement Ratio on the Compressive Strength of Cement-Based Mortars

This study investigated how the water–cement ratio and silica fume concentration affect the compressive strength of cement mortars. This comprehensive study delved into the intricate interplay between water–cement ratio and silica fume concentration, examining their influence on cement-based mortars’ compressive strength and water absorption characteristics. The silica fume concentration was investigated, ranging from 5% to 15% of the cement weight. The investigation employed two distinct mixing techniques, mixing cement and silica fume, before extracting appropriate samples; alternatively, a magnetic stirrer was used to prepare samples by dissolving silica fume in water. The cement mortars were also prepared with three different water–cement ratios: 0.44, 0.47, and 0.5. The interesting findings of compressive tests illuminated a consistent trend across all curing days and mixing methods—a reduction in the water–cement ratio corresponded with a notable increase in compressive strength. However, it is essential to note that the influence of the mixing method on the compressive strength of cement-based mortars is based on the water–cement ratio. The results show that by using the suggested technological method, it was observed that samples prepared with water–cement ratios (W/C) of 0.47 and 0.44 exhibited higher compressive strengths compared to those prepared using the well-known standard mixing method. The compressive test results underscored that the water–cement ratio reduction consistently enhanced the compressive strength in every combination of curing days and mixing techniques. Furthermore, this reduction in the water–cement ratio was correlated with a decrease in water absorption of the mortar. Conversely, the water–cement ratio itself played a pivotal role in defining how the mixing technique affected the compressive strength and water absorption of cement-based mortars. This multifaceted exploration underscores the nuanced relationships between key variables, emphasizing the need for a comprehensive understanding of the intricate factors influencing the mechanical and absorptive properties of cement-based materials.

Impact of Graphene on Microstructure and Compressive Strength of Cement Mortars Utilizing Two Different Dispersion Methods

Impact of Graphene on Microstructure and Compressive Strength of Cement Mortars Utilizing Two Different Dispersion Methods

A reusable graphene oxide aerogel for pre-concentrating and recovering uranium from water and valorisation of spent material in a cementitious material

Graphene oxide is an excellent substrate for pre-concentrating and recovering uranium in water. However, the need for scalable and affordable methods for producing graphene oxide has hindered its field applications. Besides, a sustainable strategy is required to recycle spent adsorbents and prevent them from entering the waste stream. In these contexts, this paper describes the application of graphene oxide aerogel (GOA) produced from graphite through a single-step combustion route for pre-concentrating and recovering uranium in water. The method allows GOA production in bulk quantity at 8–10 times less cost than prevalent Modified Hummer's graphene oxide (HGO). The paper also demonstrates using spent GOA as an active admixture in mortar to improve its mechanical properties. The physicochemical properties of the GOA and mechanistic details of uranium surface bindings were studied thoroughly. GOA showed enhanced uranium adsorption capacity (278 mg/g) compared to HGO due to abundant hydroxyl, carboxyl, and epoxy groups on GOA. However, the presence of HCO3− in water reduced uranium uptake due to highly water-soluble uranium-carbonate complexes such as (UO2)2CO3(OH)3−,UO2(CO3)34−, and UO2(CO3)22−. The addition of the spent GOA improved the cement mortar's compressive strength by 15 % compared to the pristine cube and arrested the leaching of residual uranium. The GOA addition and associated enhancement in compressive strength help to save cement and lower CO2 emissions. In short, the present work addresses the critical challenges of using GOA in pre-concentrating and recovering aqueous uranium, such as bulk production, production cost, and spent materials disposal.

Thermal activation mechanism and activity evaluation of lithium slag: Insights from simulated hydration

Lithium slag (LS), a by-product of lithium extraction process, is usually stacked on the surface, occupying a significant amount of land area and leading to various environmental concerns. In this study, the pozzolanic activity of LS was improved by the thermal activation method, and its hydration reaction and hydration products were studied under simulated hydration conditions. The changes of macroscopic and microscopic appearance, particle size, chemical composition and chemical bonding of LS were studied at different thermal activation temperatures (0–1100 °C). Subsequently, the activation effects of LS at different temperatures were preliminarily assessed using a dissolution tests, and its hydration process and products were investigated under simulated hydration conditions. Finally, thermally activated LS was used to prepare cement mortar. The results indicated that spodumene decomposition raised the amorphous phase content in LS, thereby enhancing its pozzolanic activity. However, it is important to note that the activity of the amorphous phase in calcined LS was relatively poor and its hydration reaction proceeded at a slow pace. The presence of sulfate in LS was critical for enhancing the 7-d compressive strength of cement mortar. The amorphous phase was contributed to the later strength development of LS-PC mortar. LS activated at 600–700 °C significantly improved the early strength of cement mortar while ensuring better strength development. After 90 d of curing, the compressive strength of LS600 achieved 70 MPa. By understanding these key findings, the amount of LS in cement-based materials can be maximized to improve the comprehensive utilization rate of LS. However, due to the high SO3 content in LS, the influence of LS on the volumetric stability of the cement-based material is still a subject that necessitates further research.

Effects of thermal activation on the hydration performance of lithium slag–cement composite binder

In order to enhance the utilisation efficiency of lithium slag (LS) in cement-based materials, calcification and thermal activation of LS were conducted, and the activation mechanism was analysed. Results showed that gypsum and spodumene in LS decomposed at high temperature by way of calcification and thermal activation, and spodumene as well as limestone calcination decomposed at high temperature, to generate more CS, CA and other mineral phases. Calcification and thermal activation could enhance the activity of LS to participate in pozzolanic reaction, and generate the formation of more hydration products. After calcification and thermal activation of LS, the hydration exothermic peak, the total amount of hydration heat and the hydration production of LS composite binder were significantly increased. The hardened matrix was more compact with less porosity. Compared with cement mortar incorporating raw LS, the incorporation of calcified and thermally activated LS enhanced the compressive strength of cement mortar at 3, 7 and 28 days by 25.8, 13.4 and 20.5%, respectively.

An investigation of the bio-medical waste ash on cement mortar bricks

Personal protective equipment (PPE), and particularly face masks, have become widespread during the COVID-19 epidemic. One of the most pressing ecological, monetary, and social problems facing the world today is the proper disposal and management of solid waste. There may be incinerators in different parts of the globe, but biomedical waste (BMW) has always been a problem. The effect of using biomedical waste ash in lieu of fine aggregate on the compressive strength of cement mortar is discussed. Cement mortar mixes were created with ratios of 1:1, 1:2, and 1:2:4, as well as 5:15:5, 25%, and 35%. Results for 15% and 25% replacement of Bio-Medical Waste ash in concrete were favourable, but those for 35% replacement resulted in a decrease in compressive strength. The 15% replacement level is chosen as the optimal proportion after comparing all the experimental test findings.

Estimation of compressive strength of cement mortars using impulse excitation technique and a genetic algorithm

Compressive strength, a crucial mechanical property of cement mortars, is typically measured destructively. However, there is a need to evaluate the strength of unique cement-based samples at various ages without causing damage. In this paper, a predictive framework using a genetic algorithm (GA) is proposed for estimating the compressive strength of ordinary cement-based mortars based on their dynamic elastic modulus, measured non-destructively using the impulse excitation technique. By combining the Popovics model (PM) and the Lydon–Balendran model (LBM), the static elastic modulus of samples was calculated using constant coefficients, representing an equivalent compressive strength. A GA was then employed to determine optimal values for these coefficients. The results showed that the LBM-based strength was dominant in the middle range of the dynamic Young's modulus while the PM-based strength was dominant for higher and lower values of the dynamic Young's modulus. The model was found to have a small root mean square error (3.1%). The findings suggest that this non-destructive model has potential for predicting the mechanical properties of cement mortars. It allows efficient evaluation of compressive strength without destructive testing, offering advantages for reliable assessments of cement-based materials.

Novel application of potassium methylsiliconate in cement-based materials: Retarding of hydration process and improvement of compressive strength

The presented research investigates the application of the organosilicon compound named potassium methylsiliconate (MESI) as a set-retarding admixture for cement-based materials which also provides the strengthening effect. The study concerns the impact of three dosages of MESI (1%, 2% and 3% per cement mass) on the properties of the cement paste, mortar and concrete. The greatest delay of the setting time of cement CEM I 42.5 R and retardation effect, examined by manual Vicat apparatus, was observed for addition of 1% methylsiliconate. The beginning of the setting was prolonged to 23 h. The influence of potassium methylsiliconate on the kinetics of cement hydration was investigated by isothermal calorimetry. The calorimetric results disclosed significant extension of induction period during Portland cement hydration with addition of potassium methylsiliconate as an admixture. It is especially visible in case of addition of 1% of MESI. Moreover, tests performed at 30 °C, 40 °C and 50 °C showed that MESI can also delay the cement hydration at higher temperatures. The influence of potassium methylsiliconate on the compressive strength of cement mortar and concrete after 1, 2, 7, 28 days and72 days was also investigated. In the first days of hydration, the compressive strength of the materials was reduced, but after 28 days of curing the compressive strength was increased by 21% and 16% for cement mortar and concrete, respectively. The impact of MESI on the microstructure and pore size distribution of cement pastes in 2nd, 7th and 28th of hydration was examined by mercury intrusion porosimetry (MIP). The result showed significant delay in the development of the cement pastes microstructure during the first days of hydration. The XRD and DTA/TG analysis provided the knowledge about impact of siliconate on the composition and formation of the cement phases. Both, the XRD and DTGA/TG analyze showed noticeable changes in portlandite formation during the first days of hydration. The conducted research and obtained results reveal the innovative and novel application of potassium methylsiliconate as retarders, which prolongs the workability of fresh mixture and improves the compressive strength of matured concrete and mortar. This admixtures can be a competitive alternative to traditional retarders.

Macro and micro properties of the cement-based material mixed with coral powder and GGBFS under seawater condition

On island, the use of discarded coral reef is a way to resolve the lack of raw material for preparing concrete. Discarded coral reef can not only be used as aggregate, but be ground to powder to replace cement. Since the cement-based material prepared with discarded coral reef is exclusively used on island, the property of the cement-based material exposed to seawater condition should be studied. In this study, discarded coral reef is ground into coral powder (CP). CP is used together with ground granulated blast furnace slag (GGBFS) to replace Portland cement (PC) partially to prepare a mixture with good performance and the minimum use of PC. The compressive strength, solid phase composition and pore structure of the cement-based material exposed to seawater condition are investigated systematically. The results show that the addition of CP decreases the fluidity of the cement mortar since it has a more rough surface than other raw materials. Although the use of CP decreases the compressive strength of cement mortar, the coupled use of GGBFS can largely mitigate the strength loss of the cement mortar by comparing 9 mixtures. When the specimens are exposed to seawater, the strength of cement mortar only decreases slightly, but the pore structure of cement paste is densified. It suggests that the use of CP and GGBFS together in the concrete can meet the construction of island; the compressive strength of the sample made with 25% CP and 25% GGBFS is around 54 MPa after exposed to seawater to 1 year.

Enhancing mechanical and thermal properties of sustainable cement mortar through incorporation of olive solid waste aggregates

This research paper presents a comprehensive investigation into the characterization of cement mortar incorporating olive solid waste aggregates (OSW) as a partial replacement for natural sand. Different levels of OSW content (0%, 5%, 10%, and 15%) were used to create samples, enabling a comparison of their mechanical and thermal properties against the reference mortar. The primary objective of this study is to analyze the mechanical and thermal performance of lightweight cement mortar, with a secondary focus on establishing correlations between distinct testing methods, including compressive strength, sclerometer, and thermal tests. Mechanical properties were assessed through compressive strength testing. After a 28-day curing period, the mortar containing 5% OSW exhibited a compressive strength of 33 MPa. Notably, it demonstrated a 15.6% reduction in density compared to the reference mortar. An examination of the relationship between destructive compressive strength tests and non-destructive sclerometer tests (NDST) revealed a linear correlation, suggesting the effectiveness of the sclerometer test in estimating cement mortar compressive strength. Furthermore, we investigated the thermal characteristics of OSW-incorporated cement mortar. The mixture containing 5% OSW exhibited a thermal conductivity of 0.87 W/m·K, representing a 21% reduction compared to the reference mortar. These findings underscore the potential of OSW to enhance the thermal properties of the resulting cement mortar. Additionally, the observed correlation between compressive strength and thermal conductivity highlights a significant connection between these properties. This study primarily addresses the mechanical and thermal attributes of cement mortar incorporating OSW while also exploring correlations between testing methods. The resulting cement mortar meets the minimum strength requirements for structural applications as a construction material.

The Use of Biosilica to Increase the Compressive Strength of Cement Mortar: The Effect of the Mixing Method.

In this work, the effect of biosilica concentration and two different mixing methods with Portland cement on the compressive strength of cement-based mortars were investigated. The following values of the biosilica concentration of cement weight were investigated։ 2.5, 5, 7.5, and 10 wt.%. The mortar was prepared using the following two biosilica mixing methods: First, biosilica was mixed with cement and appropriate samples were prepared. For the other mixing method, samples were prepared by dissolving biosilica in water using a magnetic stirrer. Compressive tests were carried out on an automatic compression machine with a loading rate of 2.4 kN/s at the age of 7 and 28 days. It is shown that, for all cases, the compressive strength has the maximum value of 10% biosilica concentration. In particular, in the case of the first mixing method, the compressive strength of the specimen over 7 days of curing increased by 30.5%, and by 36.5% for a curing period of 28 days. In the case of the second mixing method, the compressive strength of the specimen over 7 days of curing increased by 23.4%, and by 47.3% for a curing period of 28 days. Additionally, using the first and second mixing methods, the water absorption parameters were reduced by 22% and 34%, respectively. Finally, it is worth noting that the obtained results were intend to provide valuable insights into optimizing biosilica incorporation in cement mortar. With the aim of contributing to the advancement of construction materials, this research delves into the intriguing application of biosilica in cement mortar, emphasizing the significant impact of mixing techniques on the resultant compressive strength.

Mechanical Behavior of Nano Clay on Cement Mortar at Ambient Temperature

The Experimental studies prove that the use of cement as a partial replacement with Nano clay and polypropylene fibres along with Ground Granulated Blast Furnace Slag improves the strength properties like compressive strength of cement mortar at ambient temperature. These Nano clay has been successfully recognized as promising advanced materials used for construction purpose due to their enhanced mechanical properties. The primary focus and purpose of this study is to investigate the effect of Nano Clay and its properties on cube specimens. The test specimens consist of cubes (70.6 mm) as per IS specifications, the specimens were casted for 3 days and 7 days and tested with cement mortar mix 1:3, and polypropylene fibres (0.25% by weight of cement) all the test specimens are subjected to ambient temperature then, and strength properties at normal temperature were studied. The test result shows there is a significant improvement in 3 days and 7 days strength as compared to the conventional mortar. The inclusion of Nano clay will have significant improvement and high boning properties when it is added to the cement.

Effect of inclusion of natural pozzolan and silica fume in cement - based mortars on the compressive strength utilizing artificial neural networks and support vector machine

This study illustrates the effect of incorporating natural pozzolan (NP) and silica fume (SF) in cement-based mortars on the compressive strength. Up to 40% of the weight of cement in cement mortars can be replaced by NP powder. NP in its natural state can be used to replace up to 40% of the volume of sand in cement mortars. The replacement levels of cement by weight with SF are 5% and 10% to improve the mechanical properties of the NP-based cement mortars. Experiments were conducted to assess the compressive strength of cement mortars containing NP at 28 and 180 days of curing. The water/cement ratio was 0.49 for all the specimens. Models for the compressive strength of NP-based cement mortars and NP-SF-based cement mortars were formulated based on nonlinear regression analysis, artificial neural network (ANN) , and support vector machine (SVM) approach to explore the impact and exchanges of cement, NP, and SF mixtures. The RMSE of the nonlinear, ANN, and SVM models revealed that the RMSE of the ANN is significantly less than that of the nonlinear and SVM models. A sensitivity analysis for the predicted compressive strength of NP-based cement mortars and NP-SF-based cement mortars was conducted. The application of the SVM technique was evaluated through four different kernels, including sigmoid, linear, polynomial, and radial basis function (RBF). The RBF kernel shows better performance and offers more accurate results than the sigmoid, linear, and polynomial kernels. The results showed that the NP replacing cement and the SF replacing cement are the most dominant parameters for the prediction of compressive strength. Finally, the developed models from this study can be used to predict the compressive strength of cement mortars containing NP and SF.

Analysis of Rheological Characteristic Studies of Fly-Ash-Based Geopolymer Concrete

Concrete is a versatile construction material used along with a reinforcement. Concrete is made up of binder materials and aggregates. Cement is a primary binder material used to produce conventional concrete. Carbon dioxide emissions in the atmosphere are a symptom of the issue related to Portland cement manufacture. It is estimated that one ton of cement produced releases an equal amount CO2 into atmosphere. On other hand, many industrial wastes are dumped in open spaces, leading to land pollution. Researchers have developed a construction material known as geopolymer concrete that uses industrial waste materials as a binder material to address these two issues. Excellent mechanical and durability characteristics are displayed by geopolymer concrete. For the creation of geopolymer concrete, fly ash is employed as a binder material. The drawback of utilizing fly ash is the curing method. Due to increased setting time, concrete samples require either heat curing or oven-curing. Geopolymer paste preparation is based on the type of binder materials used. In this study, GGBS is partially added with fly ash to cure specimens in ambient temperature due to presence of a higher amount calcium in GGBS. The present study investigates the consistency of geopolymer pastes, their workability, and the compressive strength of cement mortars by varying the amount of binder content (360 kg/m3 & 400 kg/m3). The molarity of NaOH was varied from 8 to 12. The ratio between binder material and alkaline to binder ratio were 0.45 and 0.50, respectively. The specimens were cured in both ambient and oven temperatures to study their strength development caused by temperature. A total of 396 specimens were cast to study the behavior of geopolymer concrete made with fly ash and GGBS (FAG). The test results revealed that the substitution of 50% GGBS with fly ash exhibited better strength properties during curing. Additionally, by increasing the binder content to 400 kg/m3, the results of 80% GGBS and 20% fly ash revealed excellent consistency among all other mixes. The oven-cured specimens showed more strength compared to specimens cured in ambient temperature, but the ambient cured specimens (ACS) attained the required strength. It was also not practically possible to cure the structural members by oven-curing in the field. The mix with 80% of GGBS and 20% fly ash can be used for construction. The required strength can also be achieved by increasing the molarity ratio.

Reactivity Assessment of Supplementary Cementitious Materials and Their Binary Blends Using R3 Test

The suitability of the rapid, relevant, and reliable (R3) heat of hydration and bound water tests for measuring the reactivity of various supplementary cementitious materials (SCMs) and their blends with calcium hydroxide (CH) was investigated in this study. These tests have been recently standardized in current standards. The test was carried out on pastes of fly ash (FA), slag (S), kaolinitic calcined clay (K), limestone (LS), and their blends. A detailed analysis of the heat of hydration and bound water measurements specified according to the R3 test was carried out. A good correlation was found between the two types of test results and also between the reactivity test results versus strength activity index measured using cement mortar compressive strength. The formation of hydration products in the R3 test paste specimens was also studied using X-ray diffraction (XRD). The hydration products for SCMs formed in the test were similar to those reported in cement systems. It was seen that the interactions in the blended SCMs with CH were also similar to those reported in cement pastes. Further, the microstructure of the specimen was studied using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis, and the overall hydration of various SCMs was studied. The influence of the proportions of the SCMs in the blended SCMs and that of fineness were also investigated. The applicability and limitations of this test method for SCMs and their blends were discussed.