Bulk Electrical Resistivity as an Indicator of the Durability of Sustainable Concrete: Influence of Pozzolanic Admixtures

Featured Application

Structural concrete for coastal areas with high chloride content.

Abstract

Premature deterioration of concrete structures in coastal areas requires a careful evaluation based on durability criteria. Electrical Resistivity (ER) serves as a valuable indicator of concrete durability, as it reflects how easily aggressive agents can penetrate its pores. This testing method offers several advantages; it is non-destructive, rapid, and more cost-effective than the chloride permeability test (RCPT). Furthermore, durable concrete typically necessitates larger quantities of cement, which contradicts the goals of sustainable concrete development. Thus, a significant challenge is to create concrete that is both durable and sustainable. This research explores the effects of pozzolanic additives, specifically Volcanic Ash (VA) and Sugarcane Bagasse Ash (SCBA), on the electrical resistivity of eco-friendly concretes exposed to the coastal conditions of the Gulf of Mexico. The electrical resistivity (ER) was measured at intervals of 3, 7, 14, 21, 28, 45, 56, 90, and 180 days across 180 cylinders, each with dimensions of 10 cm × 20 cm. The sustainability of the concrete was evaluated based on its energy efficiency. Three types of mixtures were developed using the ACI 211.1 method, maintaining a water-to-cement (w/c) ratio of 0.57 with CPC 30 R RS cement and incorporating various additions: (1) varying percentages of VA (2.5%, 5%, and 7.5%), (2) SCBA at rates of 5%, 10%, and 15%, and (3) ternary mixtures featuring VA-SCBA ratios of 1:1, 1:2, and 1:3. The findings indicated an increase in ER of up to 37% and a reduction in CO₂ emissions ranging from 4.2% to 16.8% when compared to the control mixture, highlighting its potential for application in structures situated in aggressive environments.

1. Introduction

Reinforced concrete (RC) is considered an artificial rock created by humans, making it a durable material that can withstand various environmental conditions [1]. However, in coastal areas, excessive chlorides can lead to electrochemical corrosion of the reinforcing steel [2]. As a result, RC structures in these environments often experience premature damage [3]. The primary reason for this deterioration is the failure to consider the interaction between the structure and its environment [4]. The extent of deterioration depends on both the aggressiveness of the environment and the permeability of the concrete [5], which is influenced by factors such as the degree of hydration, the water-to-cement (w/c) ratio, and the quality of the materials used. Therefore, in adverse climatic conditions, special designs are necessary to ensure the durability of concrete [4]. This involves creating a network of finer pores with lower permeability to prevent harmful external agents, such as chlorides, from penetrating the material [6,7].

Regulations have evolved to include durability criteria that specify minimum cement contents ranging from 300 to 450 kg/m³ [8]. This change results in stronger, less permeable, and more durable concrete. However, it also comes with increased costs and reduced energy efficiency. The manufacturing of one ton of cement emits between 820 and 1000 kg of CO₂ [9,10], with an average estimate around 850 kg of CO₂ per ton of clinker [11]. According to the International Energy Agency [12], the cement industry is the second largest industrial emitter of CO₂. In 2022, its global production reached 4.1 billion metric tons [13], accounting for approximately 8 to 10% of global CO₂ emissions [10,14]. In response to these challenges, the industry has initiated promising sustainability efforts over the past decade, aiming to achieve zero emissions by 2050 [9,15].

There is a growing demand for eco-friendly materials to help reduce the negative impact on the environment [16]. In response to the challenges of achieving both energy efficiency and durability, sustainable concrete has emerged. This type of concrete utilizes innovative techniques that consume less carbon and energy compared to traditional concrete [17,18]. Sustainable concrete replaces cement with industrial waste materials [1], such as pozzolanic ashes, which enhance the density of the cement paste [19]. This alteration leads to a reduction in pore continuity, making it more difficult for chlorides to penetrate [20,21]. Furthermore, the ashes fill the voids left by sand within the granular structure [22]. Consequently, this results in concrete that requires smaller amounts of cement while exhibiting lower permeability and greater durability [23].

In recent years, several studies have explored the potential of using various materials as alternatives to traditional pozzolans in concrete. Examples of these materials include corn stover ash [24], ternary mixtures of volcanic ash with steel fibers [25], banana leaf ash [26], rice husk ash [27], basil ash [28], coconut shell ash [29], oat husk ash [30], and cashew leaf ash [31], among others. Most of these studies primarily focus on evaluating the mechanical properties of the concrete, while the influence of these pozzolans on durability and energy efficiency remains underexplored. Traditionally, strength tests have been the main criterion for concrete acceptance. However, evolving regulations now require a more comprehensive evaluation that also includes durability. A significant challenge is the lack of a universal test for accurately assessing durability [32], which has become a key focus for structural engineers, designers, and architects. Many previous studies either do not address durability or rely on indirect methods such as water absorption, porosity determination, or the Rapid Chloride Permeability Test (RCPT) [33]. The disadvantage of the methods mentioned is that they do not directly measure chloride permeability, and they require many hours for sample preparation and testing [7]. As an alternative for evaluating durability in this study, the electrical resistivity (ER) test was utilized. This test offers several advantages over previous methods: (1) the procedure and sample preparation are much simpler [7], (2) it can be completed in less than five minutes per specimen, and (3) it is a non-destructive test that can be performed before the strength test. The ease of application has led to an increase in the use of ER as a quality control tool over the last three decades [34] because it correlates with key stages in the life cycle of a structure: the initiation period (chloride penetration) and the propagation period (corrosion rate). As such, it serves as an indicator of susceptibility to chloride penetration [35].

This study investigates the impact of Volcanic Ash (VA) and Sugarcane Bagasse Ash (SCBA) on the electrical resistivity (ER) of green concretes, as well as the overall performance of the material. Previous research has examined ER and pozzolanic additions separately; however, there is limited comparative analysis on how these additions affect ER, energy efficiency, and the reduction in heat generated during hydration. The ER technique was selected to monitor these experimental mixtures to predict the likelihood of corrosion in reinforced concrete structures and assess their feasibility for application in the coastal areas of the Gulf of Mexico, which are characterized by high chloride concentrations. The sustainability of the concrete was evaluated by analyzing the energy efficiency implications of replacing various percentages of cement with pozzolanic materials. This research contributes valuable insights into the ER of sustainable concretes with water-to-cement ratios greater than 0.45, as well as the environmental viability of their production. Additionally, the study provides information regarding the reduction in the heat of hydration (or fresh temperature) for each type of mix, which may indicate the potential for using these sustainable concretes for thermal insulation purposes and their possible impact on building sustainability.

The study focuses on the durability of concrete (measured through ER), because the research was carried out in the Veracruz-Boca del Río metropolitan area (VBMA), which belongs to the coasts of the Gulf of Mexico. This region stands out for its corrosive aggressiveness along with the city of Coatzacoalcos [36,37,38]. The atmospheric classification of the VBMA, according to the international standard ISO 9223 [39], corresponds to a C-5 environment (very high corrosivity) [36]. This classification is due to its temperatures, which can reach above 40 °C in summer, a relative humidity above 80% and the high concentrations of chlorides and SO₂. Thus, durable concretes are required for the construction of structures, without losing the sustainable construction trends that currently prevail in the construction industry. Furthermore, if sustainable concretes based on binary and ternary mixtures of this research are suitable for the VBMA with high levels of corrosivity, they may also be applicable to the rest of the coastal areas of the Gulf of Mexico that have lower categories of corrosion.

2. Materials and Methods

2.1. Electrical Properties of Concrete

When discussing concrete, the focus is often on its mechanical properties, such as compressive strength, modulus of elasticity, and plasticity. However, the electrical properties—specifically resistivity and conductivity—are also crucial. These properties reflect how concrete responds to electric current and are influenced by the material’s structure [40]. Electrical conductivity measures a material’s ability to conduct electric current, while electrical resistivity (ER), the inverse of conductivity, indicates the material’s capacity to resist the flow of current per unit volume. For ER calculations, a sample with a cross-section of 1 m² and a thickness of 1 m is considered, with the unit of measurement expressed in Ω cm [40,41]. According to Ohm’s Law, ER can be determined using Equation (1). Finally, clearing from Equation (1) the value of ρ, Equation (2) is obtained, which allows the ER to be calculated.

$$R_e={\displaystyle \frac{V}{I}}=\rho {\displaystyle \frac{L}{A}}$$

(1)

$$\rho =R_e {\displaystyle \frac{A}{L}}$$

(2)

where

$R_e=$ electrical resistivity [Ω]

V = voltage between the electrodes [volts]

I = intensity of the electric current flowing through the material [amperes]

ρ = electrical resistivity [Ω cm] o [Ω m]

L = length of the conductive material [m] o [cm]

A = area or cross-section [m²] o [cm²]

Materials can be classified based on their behavior concerning electricity into three categories: (1) insulators, (2) conductors, and (3) semiconductors [42]. In its dry state, concrete has a high electrical resistivity (ER) [43] and is considered a dielectric (insulating) material [44]. However, in humid environments, the ER can decrease significantly due to the presence of water and ion migration, causing concrete to behave more like a semiconductor [45]. This is why the ER can vary widely, ranging from 10⁶ Ω-m in oven-dried samples to 10¹ Ω-m in saturated concrete [46,47,48].

Several factors influence the electrical resistivity of concrete, including: (1) the degree of saturation of the material, (2) the microstructure of the paste, and (3) temperature changes. The degree of saturation is crucial because electric current is transported by ions dissolved in the pore solution. Increased humidity and larger interconnected pores lead to lower ER values. Therefore, ER serves as an indirect indicator of both porosity and water saturation in the material [41]. Additionally, the microstructure of the paste is largely determined by the water-to-cement (w/c) ratio, which affects both its porosity and permeability. Lower water-to-cement (w/c) ratios, extended curing times (hydration), and the incorporation of reactive minerals all contribute to an increase in the electrical resistivity (ER) [46]. Additionally, temperature changes impact the ER; higher temperatures result in an increase in ion concentration in the pore solution and a decrease in the ER [49,50]. Based on laboratory studies conducted by various researchers, Polder [35] determined that the ER varies by 3% for saturated concrete and 5% for dry concrete with each degree Kelvin of temperature change. Therefore, it is advisable to maintain a reference temperature between 20 °C and 23 °C [35,47,49]. If the cylinder temperature deviates from this range, adjustments should be made using the Arrhenius Law, as represented in Equation (3).

$${\rho }_{t-ref}={\rho }_t exp ⌊{\displaystyle \frac{E_{A-cond}}{R}}\left({\displaystyle \frac{1}{T}}-{\displaystyle \frac{1}{T_{ref}}}\right)⌋$$

(3)

where

• ${\rho }_{t-ref}=$ resistivity to the temperature of reference (23 °C) [Ω m]
• ${\rho }_t=$ resistivity to the temperature of the trial [Ω m]
• $E_{A-cond}=$ energy of activation by conduction [kJ/mol]
• $R =$ universal constant of the gases [8.314 J/(mol °K)]
• $T =$ temperature of the test [°K]
• $T_{ref} =$ temperature of reference, for example, at 23 °C [296.15 °K]

The electrical resistivity (ER) of concrete allows for the assessment of several important factors: (a) hardening in the fresh state, (b) degree of curing, (c) resistance to chloride penetration and carbonation, and (d) the corrosion rate of the embedded steel by indicating the level of humidity within the concrete [51]. The use of ER has become more widespread because it serves multiple purposes: (1) evaluating the risk of corrosion, (2) quality control in concrete production [46], and (3) assessing the hydration process. Initially, the electrical resistivity of concrete is very low, but as cement hydrates and the concrete sets and hardens, the resistivity increases in tandem with the mechanical strength. In concrete without additives, a higher electrical resistivity indicates lower porosity and greater mechanical strength, as it suggests a higher solid phase per unit volume [41].

2.2. Measurement Techniques and Regulations for ER

There are three techniques for evaluating electrical resistivity:

1. sulk electrical resistivity (BER): This technique is measured using the direct method.

2. surface electrical resistivity (SER): This is measured using the Wenner method.

3. embedded electrodes: This method is used for measuring fresh concrete.

In Mexico, the Standard NMX-C-514-ONNCCE-2019 [52] outlines the procedures for measuring the electrical resistivity (ER) of concrete and identifies two types of resistivity:

1. apparent resistivity (AR): This is measured in unsaturated concrete that contains water within in situ concrete elements. The AR measurement utilizes either the 4-point or the Wenner method.

2. wet electrical resistivity (WER): This is measured in a laboratory on concrete samples (cylinders or cores) that have been saturated with water for at least 24 h. Both the direct method and the Wenner method can be applied for WER measurements.

The standard recommends using an alternating current (AC) source for these measurements, as direct current (DC) can cause polarization of the metal electrodes, leading to inaccurate results.

At the international level, the ASTM C 1876 standard [53] has established guidelines for measuring apparent electrical resistivity in situ, while the AASHTO standard T 358 [54] assesses the surface resistance of concrete. Additionally, the AASHTO TP 119 standard [55] specifies the procedure for determining mass electrical resistivity.

2.3. Experimental Design

The experimental design was divided into three parts (Figure 1). The first stage involved characterizing the materials. In the second stage, we manufactured concrete mixtures and determined their mechanical and electrical properties. Finally, the third stage included an analysis of the energy efficiency of each mixture. Several variables were kept constant throughout the experiment, including the water-to-cement (w/c) ratio, the granulometry of the aggregates, the type of cement, and the method of curing. We considered three independent variables: (1) the type of pozzolan, (2) the percentage of the addition, and (3) the duration of the tests. A noise factor identified in the study was the relative humidity (RH) of the environment on the day of casting. For fresh concrete, we evaluated the following properties: (1) slump (ASTM C 143) [56], (2) unit weight (ASTM C 138) [57], and (3) temperature (ASTM C 1064) [58]. For hardened concrete, we measured two output variables: (1) compressive strength (ASTM C 39) [59] and (2) bulk electrical resistivity (REM) according to NMX-C-514-ONNCCE.

2.4. Materials Used

The concrete mixes were prepared using CPC 30 R RS cement produced in Mexico, along with river sand, gravel, and water sourced from the municipal water supply of Veracruz City and Port, located in the Gulf of Mexico region.

2.5. Collection and Processing of SCBA and VA

The sugarcane bagasse ash (SCBA) was obtained in March 2024 through a donation from the La Gloria Sugar Mill, which is situated 42 km from Veracruz City and Port, Mexico. According to the information provided by the sugar mill, the combustion process occurs at temperatures between 850 °C and 900 °C. The ashes are collected in a wet form from the bottom of the boiler at the sugar mill. In the laboratory, the wet ashes were placed in an industrial dryer at 100 °C for 8 h to remove moisture (Figure 2). After drying, the ashes were sieved using a No. 100 mesh screen.

The volcanic ash was collected in a dry state in Puebla, Mexico, eliminating the need for any additional drying process. This ash originates from the eruptions of the Popocatépetl Volcano in mid-2024. However, there was an issue with the ash containing organic residue, which was removed by sieving through 100 and 200 mesh screens.

2.6. Characterization of Materials

2.6.1. Sand and Gravel

The sand was spread out and left to dry naturally for 24 h before being sieved through a No. 4 mesh screen, with any retained material discarded. The gravel was sieved through a 1-inch mesh screen and then washed. After washing, it was spread out and allowed to dry naturally for 48 h. The volumetric weight of the stone aggregates was determined according to ASTM C 29 [60]. The samples were saturated for 24 h, after which the density and percentage absorption of the fine aggregate were measured following ASTM C 128 [61], while the coarse aggregate was assessed according to ASTM C 127 [62]. The granulometric analysis of the stone aggregates was conducted in accordance with the ASTM C 136 standard [63], with results complying with ASTM C 33 [64]. A summary of the obtained properties is presented in

Table 1. Characteristics of aggregates for concrete design.

Characteristics	Sand	Gravel
Volumetric Weight (kg/m3)	1510	1417
Density (g/cm3)	2.45	2.50
TMA	-	¾″
% absorption	5.26	2.04
Fineness Modulus (FM)	2.90	7.25

.

2.6.2. Chemical Analysis of SCBA, VA and Cement

The results from the X-ray Fluorescence (XRF) studies on the SCBA, VA, and cement samples are presented in

Table 2. Characteristics of the oxide components of cement and additives.

Oxide Component	Cement	SCBA	VA
SiO2	14.44	65.91	54.84
Al2O3	4.03	9.00	17.34
Fe2O3	2.47	5.13	6.43
CaO	59.81	3.57	6.49
MgO	0.97	2.41	3.81
Na2O	1.23	1.13	6.20
K2O	0.68	3.98	2.13
SO3	4.29	0.53	0.38
Others	0.71	2.72	1.62
Loss on ignition	11.37	5.62	0.76
Total	100	100	100
		80.04	78.61
SiO2 + Al2O3+ Fe2O3 ≥ 70% (ASTM C 618)		COMPLIES WITH ASTM C 618 STANDARD

. It is evident from the table that both the SCBA and VA meet the ASTM C 618 [65], which qualifies them as pozzolanic additives.

Using X-ray Diffraction (XRD), the crystallographic phases of the materials were identified. The qualitative analysis confirmed the composition of both the cement and the sugarcane bagasse ash (SCBA). As illustrated in Figure 3, the mineralogical composition of CPC 30 R RS cement shows that tricalcium silicate is the predominant phase, making up nearly 57% of the clinker composition. Additionally, the magnesium oxide (MgO) content is 1.4%, which is below the 4% limit set by the standard. The percentage of gypsum also remains within the permitted 5% as per NMX-C-414-ONNCCE-2017 [66]. Furthermore, the content of tricalcium aluminate (C3A) does not exceed the 8% threshold specified in the ASTM C 150 standard for type V cements [67].

The X-ray diffraction (XRD) analysis, as shown in Figure 4, revealed that the amorphou s component of the sugarcane bagasse ash (SCBA) makes up 74.9%. This finding aligns with the chemical composition presented in Table 2, obtained through X-Ray fluorescence (XRF), which indicates that silica (SiO₂) is the predominant component of the ash. Furthermore, the diffractogram of the SCBA indicates the presence of 3.9% quartz, which is crystalline SiO₂, and 21.2% anorthite crystals. The formation of these crystalline components is attributed to the burning of the SCBA under uncontrolled conditions in boilers, where ash may contain crystalline silica at temperatures exceeding 800 °C [68].

2.7. Preparation of Concrete Mixtures

2.7.1. Control Mix

The control mix was formulated using the ACI method 211.1 [69], for a slump between 7.5–10 cm, with a water-to-cement (w/c) ratio of 0.57. River sand and gravel sourced from the Veracruz-Boca del Río metropolitan area in Mexico were employed, as detailed in Table 1. The cement used in the mix was CPC 30 RS, and its chemical composition is provided in Table 2. The water used for all mixtures was obtained from the local supply network, which has a pH of 7.0, meeting the requirements of ASTM C 1602 [70] and NMX-C-122-ONNCCE-2019 [71]. No additives or superplasticizers were included in this mix or in the variations with different percentages of additions.

Table 3. Proportioning of the control mix per 1 m³ of concrete.

Material	Amount
Cement	360 kg
Water	205 L
Sand	727 kg
Gravel	909 kg

presents the proportions per cubic meter of concrete for the control mix.

2.7.2. Mixtures with Pozzolanic Additives

Two types of additions were used to evaluate the effect of the expanded recycling (ER): (1) artificial pozzolan (sugarcane bagasse ash, SCBA) and (2) natural pozzolan (volcanic ash, VA). Their chemical compositions are respectively shown in Table 2. Three types of green concrete mixtures were designed, each incorporating three different replacement percentages. These include: (1) Binary mixtures with SCBA, (2) Ternary mixtures with VA and SCBA in proportions of 1:1, 1:2, and 1:3 (where VA and SCBA together replace 20% of the cement by weight), and (3) Binary mixtures with VA. This results in a total of nine green concrete mixtures, along with one control mixture. The nomenclature for each of the mixtures is provided in

Table 4. Identification of concrete specimens.

Nomenclature	Mixture Type
I. CM00-Date	Control mix without additions
II. SCBA-05-Date	Mixture with 5% SCBA
III. SCBA-10-Date	Mixture with 10% SCBA
IV. SCBA-15-Date	Mixture with 15% SCBA
V. VA-SCA05-Date	Mixture with 5% VA + 5% SCBA
VI. VA-SCA10-Date	Mixture with 5% VA + 10% SCBA
VII. VA-SCA15-Date	Mixture with 5% VA + 15% SCBA
VIII. VA-2.5-Date	Blend with 2.5% VA
IX. VA-5.0-Date	Blend with 5.0% VA
X. VA-7.5-Date	Blend with 7.5% VA

.

Given that the modulus of fineness (MF) of the sand used is 2.9, the porosity of the sustainable concrete was decreased by substituting 5% of the fine aggregate with silica sand. The proportions of each type of concrete are detailed in

Table 5. (a) Proportion per m³ of concrete with artificial pozzolan. (b) Proportion per m³ of concrete with artificial and natural pozzolan. (c) Proportion per m³ of concrete with natural pozzolan.

(a)
Material	5% SCBA	10% SCBA	15% SCBA
Cement (kg)	342	324	306
SCBA (kg)	18	36	54
Water (lts)	205	205	205
Sand (kg)	690.7	690.7	690.7
Silica Sand (kg)	36.3	36.3	36.3
Gravel (kg)	909	909	909
(b)
Material	5% VA + 5% SCBA	5% VA + 10% SCBA	5% VA + 15% SCBA
Cement (kg)	324	306	288
SCBA (kg)	18	36	54
VA (kg)	18	18	18
Water (lts)	205	205	205
Sand (kg)	690.7	690.7	690.7
Silica Sand (kg)	36.3	36.3	36.3
Gravel (kg)	909	909	909
(c)
Material	2.5% VA	5% VA	7.5% VA
Cement (kg)	351	342	333
VA (kg)	9	18	27
Water (lts)	205	205	205
Sand (kg)	690.7	690.7	690.7
Silica Sand (kg)	36.3	36.3	36.3
Gravel (kg)	909	909	909

a–c.

2.7.3. Mixture Manufacturing Procedure

The materials were weighed, and the water’s pH level was verified to be at 7.0 (Figure 5a). The VAs were incorporated during the manufacturing process, while the SCBAs were pre-mixed with the cement before the mixture was introduced into the mixer (Figure 5b). Finally, the slump of the mixture was measured (Figure 5c).

Metal molds that comply with ASTM C 470 [72] were utilized for this process. The specimens were created following the guidelines of ASTM C 192 [73]. (Figure 6a), and modeling clay was used as a sealant to prevent water loss through the joints. After the manufacturing process was completed, the specimens were stored in the laboratory (Figure 6b). They were removed from the molds 24 h later and labeled according to the nomenclature provided in Table 4.

The curing procedure involved immersing the specimens in a storage tank filled with water and lime for a duration of 90 days. A total of 180 cylindrical specimens, each measuring 10 cm in diameter and 20 cm in height, were produced for each type of mixture, with 18 specimens manufactured per type, cast in two separate batches; of which 150 cylinders were for compression tests and 30 cylinders for carbonation tests and absorption tests.

2.8. Laboratory Tests

2.8.1. Compressive Strength Test

The test was conducted in accordance with ASTM C 39 [59]. Each sample was taken out of the curing chamber, surface dried with a flannel cloth, measured, weighed, and tested at 7, 28, 45, 90 and 180 days. The heading was performed using sulfur mortar, as specified in ASTM C 617 [74] (Figure 7a). The test was carried out on an ELVEC machine with a capacity of 120 tons, featuring an electric pump (Figure 7b). Three repetitions were performed for each type of mixture.

2.8.2. Bulk Electrical Resistivity Test

The bulk electrical resistivity (BER) was measured using a direct method, which involved placing two metal electrodes at the base and top of the cylinder. Two wet sponges were positioned between the metal plates and the bottom of the cylinder. A known current and voltage were then passed through the system using an ETCR model 3200C soil resistivity meter, applying alternating current (AC) (Figure 8a). The electrical resistance (R) was measured by evaluating each specimen twice, and the average value was used. With the dimensions of each specimen, the electrical resistivity (ρ) was calculated using Equation (2). Temperature readings were taken with a FLUKE brand infrared thermometer, model 62 MAX (Figure 8b), to apply temperature corrections according to Equation (3).

2.8.3. Carbonation Test

The high alkalinity of concrete (pH between 12–14) is due to the calcium, sodium and potassium hydroxides formed during hydration [75]. When atmospheric CO₂ enters through the pores of the concrete, it reacts mainly with calcium hydroxide forming carbonates, which reduce the pH of the paste to values below 9 [76]. Since the carbonation mechanism is very slow, most of the literature adopts accelerated carbonation tests (under constant temperature and humidity conditions) to estimate natural carbonation, which does not always represent a real field scenario [77].

For this reason, in this study natural carbonation tests were carried out based on the NMX-C-515-ONNCCE-2016 standard [78]. The samples were kept under exposed conditions inside the materials laboratory for a period of 12 months, exposed to the tropical climate. This type of climate favors carbonation compared to a temperate climate, so it is considered a critical environment [77].

The test method consists of cutting a concrete sample and applying a phenolphthalein solution (1 g of phenolphthalein and 100 mL of isopropyl alcohol) uniformly to the surface to be tested using a spray bottle within a maximum of 15 min from the fracture (Figure 9a,b). The depth of the colorless zone was subsequently measured using a digital vernier caliper at four points along two perpendicular diameters. The carbonation depth is the average of these four points.

2.8.4. Water Absorption by Immersion

The test was carried out under ASTM C 642 Standard [79], which indicates that the sample must be at least three individual portions of concrete (in this case cylinder pieces) if the volume of each portion is not less than 350 cm³. The samples were subjected to a drying process at 105 °C for 24 h (Figure 10a). They were subsequently allowed to cool, and their mass was determined. They were then immersed in water to achieve saturation (Figure 10b), verifying that up to two successive mass values of the surface-dried sample at 24-h intervals show a mass increase of less than 0.5% of the highest value.

3. Results and Discussion

3.1. Tests on Fresh Concrete

3.1.1. Slump

In the case of Sugarcane Bagasse Ash (SCBA), the mixtures exhibit a decrease in workability (Figure 11), ranging from 9.5 to 4 cm as the percentage of substitution increases. This reduction in workability is attributed to the higher water absorption capacity of SCBA compared to cement, due to its porous nature, as noted by Sakib et al. [80]. Conversely, mixtures incorporating Volcanic Ash (VA) either maintained their fluidity or became even more fluid. These findings align with Ghanim et al. [81], who observed the positive effect of volcanic additions on settlement. However, some studies indicate that VA mixtures can negatively impact workability [82,83]. These conflicting results may arise from variations in the mineralogical composition of the aggregates or external factors such as relative humidity, temperature, sunlight, rain, and wind, which can significantly affect the consistency of concrete by causing the loss of mixing water [84].

Since the slump tolerance in mixes designed at 10 cm is ± 2.5 cm means that slumps should be between 7.5 and 12.5 cm in unblended concrete. However, due to the addition of pozzolanic material, the mixtures had slumps lower than 7.5 cm, so the control mix was adjusted, maintaining the w/c ratio at 0.57 but with an expected slump of 15 and 17.5 cm, resulting in an increase of approximately 5.3% in cement. While this increase in cement may have a small impact on the cost per m³ of concrete, not making this adjustment would require the use of plasticizers, which would also impact the cost. However, the disadvantage is that in most cases these additives are usually purchased on special order and have a shelf life of 12–24 months, if properly stored in a cool, dry place. Finally, by having a more fluid control mix, the new mixes with pozzolanic additions had slumps between 9–17 cm, which is adequate for civil engineering construction, thus avoiding the use of super fluidizing additives.

These new blends were tested after monitoring the first 150 manufactured cylinders for three months. Only the new blends with the best performance for each binary and ternary blend (15% SCBA, 5% VA, and 5% VA-15% SCBA) were manufactured, in addition to the control blend, for a total of four types of blends. For these blends, in addition to the first 180 cylinders, another 60 cylinders were manufactured for compression testing at 7, 28, 45, 90, and 180 days.

3.1.2. Unit Mass

As the percentage of pozzolanic material substitution increases, the unit mass of sustainable concrete decreases compared to the control mixture (Figure 12). In concrete containing sugarcane bagasse ash (SCBA), this decrease ranges from 2% to 3%, similar to the values observed in ternary mixtures with both volcanic ash (VA) and SCBA. In contrast, mixtures containing only VA show a decrease of between 1% and 2%. This variation is because both types of ash have a lower density than that of cement, which ranges from 2.90 to 3.15 g/cm³. Specifically, SCBA has a density ranging from 2.19 to 2.53 g/cm³ [85], while VA has an approximate density of 2.45 g/cm³ [86]. Consequently, mixtures with SCBA exhibit the lowest unit mass, followed by the ternary mixtures. Finally, mixtures with VA have the highest unit mass among the sustainable options, as VA has the highest density and the lowest substitution percentages.

3.1.3. Heat of Hydration

The temperature in a concrete mix is primarily generated by the hydration of cement through chemical reactions. The heat produced during hydration depends on the characteristics of the cement and the ambient temperature. Therefore, a higher quantity of cement leads to greater heat generation [87]. Additionally, increasing the percentage of cement substitutes results in a lower temperature in the mix (Figure 13). The impact of ambient temperature is also significant; for example, the concrete cast in September (Lot 01) had higher temperatures compared to that cast in October (Lot 02) at the same dosages, due to the cooler ambient temperatures in October. These findings suggest that using these sustainable concretes in warmer climates can enhance thermal efficiency in buildings. This can potentially lower cooling system costs and increase the overall sustainability of the material.

3.2. Tests on Hardened Concrete

3.2.1. Compressive Strength

The results show that during the early age of concrete curing (0–28 days), there is a reduction in strength when using pozzolanic additions (Figure 14). According to López et al. [88], this slower development of strength is due to the time required for the reaction with calcium hydroxide to occur. By 45 days, the concrete containing 15% sugarcane bagasse ash (SCBA) surpasses the strength of the control mix. However, at 180 days, this strength decreases. In contrast, the mix with 10% SCBA maintains its strength over that period. For the volcanic ash (VA) mix at 2.5%, its strength at 28 days is equivalent to that of the control mix, but it decreases at 45 days and continues to decline at 90 days. The best combination is found to be the mix with 5% VA, which aligns with the findings of Elshinawy et al. [25]. The reactivity of various ashes (VAs) can be enhanced through mechanical grinding. For instance, Kupwade-Patil et al. [89] successfully achieved substitutions of up to 40% of VA by grinding the ashes from 17 mm to 6 mm. Additionally, some researchers have addressed the decrease in compressive strength at early ages by incorporating silica fume [90]. In ternary mixtures of VA and silica-corncob ash (SCBA), the combination with a 1:1 ratio (5% SCBA and 5% VA) demonstrated the best performance at both 28 and 45 days. However, at 90 days, there was a decline, with the mixture achieving only 90% of the compressive strength of the control mixture. Finally, after 6 months (180 days), 77.7% of the mixtures surpassed the compressive strength of the control mixture, except for those with 10% and 15% SCBA, which fell short by 4% and 10%, respectively.

3.2.2. Durability Test

The electrical resistivity (ER) was measured at 3, 7, 14, 21, 28, 45, 56, 90, and 180 days. The results indicate that as the age of the concrete increases, the ER values also rise (

Table 6. BER values.

Number	Type of Mixture	Surface Electrical Resistivity (KΩ cm)
		3 D	7 D	14 D	21 D	28 D	45 D	56 D	90 D	180 D
1	Control	6.35	9.11	6.68	12.06	9.41	11.88	15.33	18.72	31.89
2	5% SCBA	6.96	7.51	7.13	11.74	10.10	14.16	18.03	25.62	29.72
3	10% SCBA	6.15	6.58	9.10	10.47	12.20	23.12	23.91	23.22	32.09
4	15% SCBA	5.37	6.65	11.02	18.00	13.70	29.00	28.32	25.70	37.54
5	5% VA + 5% SCBA	4.41	6.84	8.94	10.14	11.81	15.57	19.56	22.53	33.44
6	5% VA + 10% SCBA	4.24	7.51	9.93	11.31	14.89	18.07	22.30	26.13	36.94
7	5% VA + 15% SCBA	3.01	7.04	11.69	13.00	18.06	20.26	25.30	29.13	46.80
8	2.5% VA	3.01	5.67	5.68	6.44	8.81	15.12	12.55	20.42	22.44
9	5% VA	4.03	4.02	6.53	7.39	9.91	14.00	14.78	16.94	27.85
10	7.5% VA	4.88	4.88	5.50	7.51	9.34	14.27	15.38	17.64	23.65

). This trend is illustrated in Figure 15, where it can be observed that at 180 days, the ER values for 56% of the mixtures surpassed that of the control mixture.

Additionally,

Table 7. Statistical Analysis of ER Data.

Statistical Parameter	Surface Electrical Resistivity (KΩ cm)
	3 D	7 D	14 D	21 D	28 D	45 D	56 D	90 D	180 D
Average	4.84	6.52	8.22	10.81	11.82	17.55	19.55	22.61	32.24
N	10	10	10	10	10	10	10	10	10
Variance	1.852	2.359	4.929	11.269	8.852	27.397	27.312	16.741	5.102
D. Standard	1.361	1536	2.220	3.357	2.975	5.234	5.226	4.092	2.259
Coefficient of variation	0.28	0.24	0.27	0.31	0.25	0.30	0.27	0.18	0.07
Max deviation limit	6.20	8.05	10.44	14.16	14.80	22.78	24.77	26.70	34.49
Min deviation limit	3.48	4.98	6.00	7.45	8.85	12.31	14.32	18.51	29.98
Maximum value	6.96	9.11	11.69	18.00	18.06	29.00	28.32	29.13	46.80
Minimum value	3.01	4.02	5.50	6.44	8.81	11.88	12.55	16.94	22.44

shows that the average ER of all mixtures at 180 days is 32.24 KΩ cm, with a tendency to vary by ±2.26 KΩ cm. The statistical analysis reveals that as the age of the concrete mixtures increases, the coefficient of variation decreases. This suggests a reduction in data dispersion and greater homogeneity in the durability of the various concrete mixtures.

The best ER performance was observed in mixture 7 (5% VA-15% SCBA), achieving a value of 46.80 KΩ cm after 180 days. This was followed by mixture 4, which had 15% SCBA and an ER of 37.54 KΩ cm. The results in Table 6 have been graphed (Figure 15) and the behavior of the ER has a high variability. Notably, the ternary mixture of 5% VA and 10% SCBA demonstrates a clear trend indicated by a quadratic approximation with an R² value of 0.98.

In the experiment, the value of 40 KΩ cm was not achieved after the 90 days required by the NMX-C-530-2018 [8] standard for an M2 marine environment (located 50–500 m from the coast); this is because the Standard requires for an M2 medium w/c ratios equal to or less than 0.45, which are in fact more durable, but at the same time are also more expensive and more polluting. However, this study shows that even for concretes with w/c ratios greater than 0.45 (in this case w/c = 0.57), pozzolanic additions manage to improve ER values between 37 and 55% (mixtures 4 and 7), which indicates their feasibility of use to achieve greater durability at low cost. However, the addition of pozzolans improved the electrical resistance (ER) values by 37% to 55% in mixtures 4 and 7, demonstrating their potential for enhancing durability. These results align with the findings of Mendeiros et al. [91], who suggest that concretes containing higher pozzolan content and water-to-cement (w/c) ratios below 0.60 exhibit greater resistivity due to a reduction in pore diameter. Khan et al. [92] also note that the impact of various additives (VA) on concrete durability is linked to their pozzolanic properties. Additionally, Abrão et al. [83] argue that all pozzolans, having lower calcium content than Portland cement, form different hydration compounds which improve the microstructure of the paste, leading to more durable concrete.

3.2.3. Comparison Between ER Test and RCPT

Azarsa and Gupta [48] determined, based on studies by other authors, that the correlation coefficient (R²) between surface electrical resistivity (SER) and bulk electrical resistivity (BER) ranges from 0.979 to 0.998. For practical purposes, Andrade and Climent [41] argue that equivalent results can be obtained in both cases if the appropriate factors are considered. Following this guideline, this investigation treated the BER as equal to the SER values. In this way, the ER values obtained at 56 days (Table 6) were compared with the criteria applied by Gudimettla & Crawford [93] from the AASHTO T 358 Standard [54], to obtain the correlation with the RCPT test (

Table 8. Chloride ion penetration classification [54].

Chloride Ion Penetration	RCP Test	Surface Resistivity Test
	Charges Passed, Coulombs	4 × 8 in (0.1 × 0.2 m) Cylinder, KΩ-cm	6 × 12 in (0.15 × 0.3 m) Cylinder, KΩ-cm
High	>4000	<12	<9.5
Moderate	2000–4000	12–21	9.5–16.5
Low	1000–2000	21–37	16.5–29
Very Low	100–1000	37–254	29–199
Negligible	<100	>254	>199

).

This comparison allowed for the assessment of corrosion risk based on the 56-day ER values and a possible range of chloride ion permeability (

Table 9. Correlation of SER values with RCPT (Corrosion Risk).

Number	Type of Mixture	SER (KΩ-cm)		Risk of Corrosion TP 95	Chloride Ion Permeability ASTM C 1202 (Couloms)
		56 D	180 D
1	Control	15.33	31.89	Moderate	2000–4000
2	5% SCBA	18.03	29.72	Moderate	2000–4000
3	10% SCBA	23.91	32.09	Low	1000–2000
4	15% SCBA	28.32	37.54	Low	1000–2000
5	5% VA + 5% SCBA	19.56	33.44	Moderate	2000–4000
6	5% VA + 10% SCBA	22.30	36.94	Low	1000–2000
7	5% VA + 15% SCBA	25.30	46.80	Low	1000–2000
8	2.5% VA	12.55	22.44	Moderate	2000–4000
9	5% VA	14.78	27.85	Moderate	2000–4000
10	7.5% VA	15.38	23.65	Moderate	2000–4000

), resulting in 60% of the manufactured mixtures exhibiting a moderate corrosion risk.

3.2.4. Carbonation

The results indicate that the depth of carbonation depends on the proportions of each mixture type, with greater depths of carbonation being observed as the percentages of cement replacement by pozzolanic additions increase. Except for the mixture with 5% CBCA, the remaining samples had higher carbonation values than the control mixture (3.14 mm) over the one-year exposure period. The results obtained are shown in Figure 16.

These results are consistent with Pillai et al. [94], who indicate that in general the use of supplementary cementitious materials generates a reduction in carbonation resistance because of prolonged pozzolanic reactions that generate a decrease in Ca (OH)₂. However, these authors consider that this should not be a limitation in the use of pozzolanic additions, but rather mitigation measures such as greater coatings should be adopted. Therefore, this is the reason why Regulations such as NTC-23 and NMX-C-530-ONNCCE-2018 in Mexico, consider greater coatings in the construction of coastal structures for exposure to a marine environment.

That is, although the depth of carbonation increases with pozzolanic additions and apparently there is an unfavorable scenario; some authors consider that this should not be a limitation because although the onset of carbonation corrosion is expected to occur earlier in concretes with pozzolanic additions; the spread of corrosion will depend on the availability of moisture and oxygen, as well as the ER of the concretes with additions [94].

To get an idea of whether the increase in carbonation depth a problem could be, an analysis was performed for the mixture with the highest carbonation levels (15% CBCA) with a value of 4.75 mm. From this value, the constant K_CO2 was determined using Equation (4) proposed by [95].

$$X_{CO2}=K_{CO2} \sqrt{t}$$

(4)

$$t={\left({\displaystyle \frac{e_c}{K_{CO2}}}\right)}^2$$

(5)

In which:

• $X_{CO2}=$ carbonation depth [mm]
• $K_{CO2}=$ carbonation constant [mm/year]
• $\sqrt{t} =$ exposure time of the concrete to the environment [years]
• $e_c=$ cover thickness of the structural steel [mm]

A value of K_CO2 = 4.75 mm/year was obtained, subsequently, by substituting in Equation (5) the time in which carbonation will reach the reinforcing steel in a structure is determined. Assuming the use of these concretes with a 3.5 cm (35 mm) coating, a time t of 54 years is obtained, which is higher than the useful life period proposed by NTC-23, which is 50 years. This indicates that the use of these concretes is feasible only considering higher coating values, as indicated by Pillai et al. [94].

3.2.5. Absorption by Immersion

The tests were performed on samples cured for 90 days (for all types of mixes). Absorption rates were measured after 30 min and after 72 h of saturation. Absorption after 30 min was relatively low, with the control mix having the lowest rate at 5.08%. However, in all cases the absorption rate did not exceed 10%, indicating adequate concrete quality [96]. As the percentage of cement replacement by pozzolanic materials increases, the absorption rate decreases (Figure 17) for both a saturation time of 30 min and a period of 3 days. This is consistent with the results obtained by Golewski [96], with fly ash, who attributes this behavior to the reduction in capillary pores and the densification of the microstructure of the cement matrix.

This reduction in permeability translates into an increase in durability and is corroborated by ER tests, where it was observed that the addition of pozzolanic materials increased ER values by up to 37%, indicating an increase in the durability of the mixtures.

3.2.6. Microstructure of Pozzolanic Concrete

From the test, it is observed that the addition of ashes with pozzolanic characteristics (SCBA and VA) improves the microstructure of the concrete mixtures (Figure 18). This is because the pozzolanic additions, being very fine particles, reduce the porosity, which is reflected in an increase in the ER and therefore, in the durability of the mixtures. Several studies indicate that pozzolanic additions have a higher density, lower porosity and absence of CH crystals, and all these improvements are due to the high silica content and the large specific surface area of these additions. Furthermore, during the hydration process a greater amount of hydrated calcium silicate gel (CSH) is generated, which helps to further reduce the pore size distribution and the Interfacial Transition Zone (ITZ) between the cement paste and the coarse aggregate [97,98].

3.2.7. Concrete Coloring

Supplemental cementitious materials (SCMs) can slightly change the color of hardened concrete, depending on the quantity used. Many SCMs closely resemble the color of Portland cement, leading to minimal impact on the concrete’s overall appearance [99]. For example, the use of VA (Figure 19a) has little effect on the color due to its light hue and the small percentage typically added. On the other hand, incorporating sugarcane bagasse ash (SCBA) can impart a bluish-gray tone to the concrete (Figure 19b). As the substitution percentage increases (for instance, using 15% SCBA), the concrete tends to become grayer. It is important to note that darker colors generally indicate a higher Effective Reactivity (ER) value, which is associated with greater durability. However, any increase in color depth must also be evaluated in relation to compressive strength results.

3.3. Estimation of CO₂ Emissions

The goal of this section is to measure the CO₂ emissions for each type of concrete mixture produced, based on the amount of raw materials required to make one cubic meter.

3.3.1. CO₂ Emission Factors for Raw Materials

To produce one ton of Portland cement, between 870 kg [100] and up to 1000 kg of CO₂ are released into the environment [101]. This amount varies based on the type of fuel used, whether fossil fuels or biofuels. According to Lu et al. [11], an average estimate is approximately 850 kg of CO₂ per ton of clinker. For aggregate emissions, there are 45.9 kg of CO₂ emitted per ton for coarse aggregates and 4.6 kg of CO₂ per ton for fine aggregates [100]. Additionally, the emissions for water are 0.000196 kg of CO₂ per kg [102].

To calculate the ash emission factor, we considered the amount of CO₂ emitted during the drying and sieving process. The emission factor for electrical energy used in this study was 0.521 kg CO₂ per kWh [103]. For calculating the carryover of SCBA and VA, we referenced the procedure proposed by Khalil and AbouZeid [14]. We also took into account an energy emission factor of 0.96 kg CO₂ per km for a 5 m³ dump truck, along with the hauling distances to the La Gloria sugar mill in the municipality of Úrsulo Galván for the SCBA, and the distance from Puebla, Mexico, where the VA was collected. This emission factor includes the fuel consumed for transporting the ash as well as the fuel required for the return trip of the empty truck.

3.3.2. Method for Calculating CO₂ Emissions

To estimate CO₂ emissions per cubic meter of concrete, we considered the carbon dioxide emitted during the production of raw materials for each of the ten types of mixtures prepared. The CO₂ emission values for the ingredients necessary for concrete production were sourced from the literature [11,100,102]. We applied Equation (6), following the methodology used by Kim et al. [104] and Vázquez et al. [105].

Total emissions = Raw materials + Transportation (fuels) + Screening and drying (electricity)

(6)

3.3.3. Determination of CO₂ Emissions in Mixtures

Using Equation (6), we determined the CO₂ emissions produced during the manufacturing of each mixture.

Table 10. CO₂ generated in the manufacture of mixture 1 (control).

Material	CO2 Emissions (kg- CO2/kg)	Dosage [kg/m3] of Concrete	CO2 Emissions [kg-CO2/m3] from Concrete
1. Cement	0.87 [100]	379	329.73
2. Water	0.000196 [102]	216	0.04
3. Sand	0.0050 [11]	656	3.28
4. Gravel	0.0460 [11]	941	43.29
System total			376.34

presents the CO₂ emissions for the control mixture, while Figure 20 displays the calculated values for each of the 10 mixtures produced.

The results of this study align with those reported by Jiménez et al. [106], which state that producing a cubic meter of concrete with a cement dosage of 306 kg generates emissions ranging from 347 to 351 kg of CO₂. In our study, the two mixtures containing 306 kg of cement—one with 15% sugarcane bagasse ash (SCBA) and the other with 5% vinyl acetate (VA) and 10% SCBA—produce approximately 329 kg of CO₂, which is a reduction of about 6%. In contrast, the control mixture, which contains a higher cement amount of 380 kg/m³, results in higher emissions of 376 kg of CO₂.

3.3.4. Evaluation of the Behavior of Mixtures

Each mix was evaluated based on three criteria: sustainability, durability, and mechanical resistance. Each category was assigned a maximum of 3 points. The results are presented in

Table 11. Evaluation of concrete mixtures for durability, sustainability, and strength.

Number	Type of Mixture	Sustainability			Durability (Risk of Chloride Ion Ingress)			Mechanical Resistance			Score
		Low	Average	High	Low	Average	High	Low	Average	High
		1	2	3	3	2	1	1	2	3
1	Control	Not sustainable				x				x	5
2	5% SCBA	x				x				x	6
3	10% SCBA		x		x				x		7
4	15% SCBA			x	x				x		8
5	5% VA + 5% SCBA		x			x				x	7
6	5% VA + 10% SCBA			x	x					x	9
7	5% VA + 15% SCBA			x	x					x	9
8	2.5% VA	x				x				x	6
9	5% VA	x				x				x	6
10	7.5% VA		x			x				x	7

. The top three mixes with the highest scores were: (1) the mix with 5% VA and 15% SCBA and (2) the mix with 5% VA and 10% SCBA, both achieving a perfect score of 9 out of 9 points. This indicates that they are the most durable, sustainable, and resistant mixes. The third highest scoring mix was (3) the one with 15% SCBA.

At 180 days, 77.7% of the mixes outperformed the control mix, whereas only 44.4% did so at 90 days. This suggests that while all mixtures with additions generate lower CO₂ emissions per cubic meter of concrete, they exhibit a drawback: their compressive strength is initially lower than that of the control mixture within the first three months. Although sufficient strength is achieved after six months, the pozzolanic reaction occurs more slowly, causing delays in reaching adequate resistance as the percentages of pozzolanic additions increase.

4. Conclusions

The use of sustainable concrete is a viable alternative to traditional structural concrete, especially in coastal areas, where it can help prevent or reduce premature deterioration due to its durability. Additionally, it has been confirmed that Electrical Resistivity (ER) is an effective technique for predicting the durability of concrete. One of its key advantages is that it is a non-destructive test that can be correlated with the Rapid Chloride Penetration Test (RCPT). ER testing can be completed in a shorter time, resulting in lower costs for monitoring the quality control of concrete mixtures.

The results of the study indicate that the two mixtures with the best performance in terms of sustainability, durability, and resistance were the ternary mixtures (5% VA-15% SCBA and 5% VA-10% SCBA). These mixtures outperformed the one with 15% SCBA. The findings indicate that SCBA produced under uncontrolled conditions at the sugar mill possesses pozzolanic properties, enhancing the compressive strength of the concrete. As a result, these mixtures exhibit durability improvements of 24% to 37%, depending on the percentage of replacement used. This increase in durability, due to an increase in ER, is corroborated by the results of the absorption test, where it is observed that as the substitution percentages increase, the absorption rate decreases. This indicates that the permeability of the samples is reduced due to the pozzolanic activity, while at the same time increases durability. However, a drawback is the reduced workability of these mixtures, which can be improved by using a control mixture to achieve higher slumps, specifically between 15 and 17 cm. While VA has superior properties compared to SCBA, it requires more time to develop strength. Therefore, further research is needed to explore methods for accelerating the development of mechanical strength.

Natural pozzolans offer several advantages over artificial pozzolans, primarily due to their lower processing requirements. For instance, the volcanic ash (VA) does not need a pre-drying process. Additionally, when combined in ternary mixtures with sugarcane bagasse ash (SCBA), VA can lead to a 37–39% improvement in durability. This enhancement is particularly beneficial for exposed concrete in coastal regions that face highly aggressive environmental conditions. While increasing the replacement percentages of SCBA and VA can improve the ER values, it is important to exercise caution with the maximum replacement levels. In many cases, although the durability may increase, short-term compressive strength could be compromised. Therefore, it is advisable to select replacement values that optimize both durability and compressive strength.

When it comes to sustainability, all mixtures that include pozzolanic additions demonstrate improved energy efficiency compared to the control mixture, resulting in a reduction of CO₂ emissions ranging from 4.2% to 16.8%. Considering the importance of local availability, the feasibility of using Sugar Cane Bagasse Ash (SCBA) is favorable, as the State of Veracruz is Mexico’s leading producer of sugarcane

In conclusion, the methodology proposed in this study can be utilized for further research on the addition of pozzolanic materials to concrete, examining their effects not only on strength parameters but also on durability and sustainability.