<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "https://jats.nlm.nih.gov/publishing/1.3/JATS-journalpublishing1-3.dtd">
<article article-type="research-article" dtd-version="1.3" xml:lang="en">
  <front xmlns:xlink="http://www.w3.org/1999/xlink">
    <journal-meta>
      <journal-id journal-id-type="elibrary">75504</journal-id>
      <journal-title-group>
        <journal-title>Magazine of Civil Engineering</journal-title>
        <trans-title-group xml:lang="ru">
          <trans-title>Magazine of Civil Engineering</trans-title>
        </trans-title-group>
      </journal-title-group>
      <issn pub-type="epub">2712-8172</issn>
    </journal-meta>
    <article-meta xmlns:xlink="http://www.w3.org/1999/xlink">
      <article-id pub-id-type="publisher-id">10</article-id>
      <article-id pub-id-type="doi">10.34910/MCE.141.10</article-id>
      <title-group>
        <article-title>Adaptive cost-constrained optimization of concrete mixtures using machine learning-guided genetic algorithms</article-title>
        <trans-title-group xml:lang="ru">
          <trans-title>Adaptive cost-constrained optimization of concrete mixtures using machine learning-guided genetic algorithms</trans-title>
        </trans-title-group>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-0644-2657</contrib-id>
          <name>
            <surname>Beigi</surname>
            <given-names>Mohsen</given-names>
          </name>
          <xref ref-type="aff" rid="aff1"/>
          <email>mohsenbeigi59@gmail.com</email>
        </contrib>
      </contrib-group>
      <aff id="aff1">Islamic Azad University</aff>
      <pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-02-13">
        <day>13</day>
        <month>02</month>
        <year>2026</year>
      </pub-date>
      <volume>19</volume>
      <issue>1</issue>
      <issue-id pub-id-type="publisher-id">141</issue-id>
      <fpage>14110</fpage>
      <lpage>14110</lpage>
      <self-uri xmlns:xlink="http://www.w3.org/1999/xlink" content-type="pdf" xlink:href="https://engstroy.spbstu.ru/userfiles/files/2026/19(1)/10.pdf"/>
      <abstract xml:lang="en">
        <p>This study presents an adaptive framework for optimizing high-performance concrete mixtures by integrating machine learning with a genetic algorithm under cost constraints. An experimental dataset was used to train an XGBoost model, which accurately predicts 28-day compressive strength. The trained machine learning model was embedded as the objective function within the genetic algorithm to maximize compressive strength while incorporating cost limitations defined by user-provided unit prices and budget. Unlike most previous studies that treat cost and strength as two separate objectives in multi-objective formulations, this work introduces cost as a constraint and strength as the sole optimization objective, thereby simplifying the decision-making process. To bridge the gap between theory and practice, an Android application was developed. The application enables users to input real-time material prices and budget limits, which are transmitted to a server hosting the machine learning model and genetic algorithm. The server computes optimized mix proportions and returns both the predicted compressive strength and the optimal design to the user interface. The proposed adaptive optimization framework was shown to effectively adjust to market price fluctuations and varying budget scenarios, providing a practical and flexible solution for real-world applications. Furthermore, the single-objective formulation ensures a unique optimal solution, avoiding the complexity of selecting among multiple Pareto-optimal alternatives.</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>concrete mix optimization</kwd>
        <kwd>machine learning</kwd>
        <kwd>genetic algorithm</kwd>
        <kwd>compressive strength prediction</kwd>
        <kwd>cost constraint</kwd>
        <kwd>android application</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec>
      <p>1.Introduction</p>
      <p>Concrete is one of the most widely used construction materials due to its versatility, durability, and cost-effectiveness. It is a composite material composed primarily of cement, aggregates, water, and chemical admixtures. Cement acts as the binding agent, holding the mixture together, while aggregates contribute to bulk and significantly influence the mechanical and durability properties of both fresh and hardened concrete. Water facilitates the hydration of cement and affects the porosity, strength, and durability of the hardened material. Chemical admixtures are employed to regulate physical properties and improve workability and performance [1, 2].</p>
      <p>The 28-day compressive strength of concrete is a critical performance indicator in both research and practice. It is affected by multiple factors including mix proportions, water-to-cement ratio, curing conditions, and the properties of individual components. Accurate prediction of this property is essential for ensuring safety, performance, and compliance with standards [3, 4].</p>
      <p>Cost is another significant factor in concrete production. Raw material expenses, such as cement, aggregates, and admixtures, can constitute more than half of the total production cost. Rising material prices, particularly for cement, can substantially impact project budgets. Optimizing concrete mixtures with supplementary materials like fly ash or slag can reduce costs while maintaining or enhancing performance [5, 6].</p>
      <p>However, compressive strength and production cost are generally conflicting objectives, since an increase in strength is often associated with higher costs, and vice versa. In many studies, this trade-off has been addressed through multi-objective optimization approaches, where compressive strength and cost are treated as two separate objectives to be optimized simultaneously 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 [7–17].</p>
      <p>Predicting concrete compressive strength is a complex task due to nonlinear relationships between input variables, such as mix proportions and curing conditions, and output variables. Traditional empirical models often fall short in capturing these interactions. Machine learning techniques, such as extreme gradient boosting and artificial neural networks, have demonstrated high accuracy in estimating compressive strength, effectively managing complex datasets and improving prediction reliability [18, 19].</p>
      <p>Integrating genetic algorithms with machine learning models has proven highly effective for optimizing concrete mix designs to achieve maximum compressive strength under specified constraints. Genetic algorithm explores vast solution spaces and identifies optimal solutions by mimicking natural selection. When combined with machine learning models predicting compressive strength, genetic algorithms can fine-tune mix proportions for enhanced performance. Studies have demonstrated that integrating machine learning estimators with genetic algorithms enables optimization of concrete mixtures, balancing strength, cost, and durability under quality constraints [20, 21].</p>
      <p>In this study, an experimental dataset was employed to develop a machine learning model for predicting the 28-day compressive strength of concrete. The trained model was subsequently coupled with a genetic algorithm to optimize concrete mixture proportions subject to both technical and economic constraints. In contrast to previous studies, construction cost is not formulated as a secondary optimization objective; instead, it is explicitly imposed as a constraint. This formulation allows market price fluctuations to be flexibly incorporated into the optimization framework. By enabling users to specify material unit prices and a maximum allowable budget, the proposed approach ensures that compressive strength is maximized while strictly satisfying the prescribed cost limitation.</p>
      <p>The novelty of this work lies in two main aspects. First, the optimization problem is formulated as a single-objective genetic algorithm, where the objective function is the compressive strength predicted by the machine learning model, while cost and proportional limitations are treated as constraints. This design offers a more flexible and practical framework compared to traditional multi-objective approaches. Second, to facilitate real-world application, an Android application was developed that allows users to input unit prices and budget information. These inputs are transmitted to a server hosting the machine learning model and genetic algorithm, which computes the optimal mixture proportions and returns the results to the application (Fig. 1). This user-oriented design makes the framework not only technically innovative but also highly accessible for practical decision-making in concrete mix design.</p>
      <p>Figure 1. Schematic representation of the developed framework.</p>
      <p>2.Materials and Methods</p>
      <p>2.1.Problem Formulation</p>
      <p>The present study addresses the optimization of high-performance concrete mixture proportions using a single-objective genetic algorithm. The objective function (cost function) is to maximize the 28-day compressive strength predicted by a trained machine learning model:</p>
      <p>                                               (1)</p>
      <p>where   represents the output of the machine learning model and the input variables   (all in kg/m3) the concrete constituents as defined in Table 1.</p>
      <p>Table 1. Concrete components, specific gravities, and constraint ratios.</p>
      <p>Component</p>
      <p>Symbol</p>
      <p>Specific Gravity (kg/m³)</p>
      <p>Min Ratio</p>
      <p>Max Ratio</p>
      <p>Notes / Constraint Type</p>
      <p>Cement</p>
      <p>X1</p>
      <p>3.15</p>
      <p>—</p>
      <p>—</p>
      <p>Part of binder</p>
      <p>Slag</p>
      <p>X2</p>
      <p>2.80</p>
      <p>0</p>
      <p>0.61</p>
      <p>Slag-to-binder ratio</p>
      <p>Fly Ash</p>
      <p>X3</p>
      <p>2.50</p>
      <p>0</p>
      <p>0.61</p>
      <p>Fly Ash-to-binder ratio</p>
      <p>Water</p>
      <p>X4</p>
      <p>1.00</p>
      <p>0.23</p>
      <p>0.90</p>
      <p>Water-to-binder ratio</p>
      <p>Superplasticizer</p>
      <p>X5</p>
      <p>1.35</p>
      <p>0</p>
      <p>0.13</p>
      <p>SP-to-cement ratio</p>
      <p>Coarse Aggregate</p>
      <p>X6</p>
      <p>2.50</p>
      <p>1.18</p>
      <p>5.62</p>
      <p>Coarse-to-binder ratio</p>
      <p>Fine Aggregate</p>
      <p>X7</p>
      <p>2.65</p>
      <p>0.35</p>
      <p>0.54</p>
      <p>Fine-to-total aggregate ratio</p>
      <p>The genetic algorithm aims to determine the optimal mixture proportions under a set of general, proportional, and cost constraints.</p>
      <p>2.1.1. Volume constraint</p>
      <p>The total volume of the concrete mixture must equal 1 m3, enforced using the specific gravities   of each component:</p>
      <p>                                                                    (2)</p>
      <p>This ensures that the genetic algorithm-generated mixture corresponds to a physically feasible 1 m3 concrete volume.</p>
      <p>2.1.2. Ratio constraints</p>
      <p>To maintain logical and practical mixture proportions, the ratio constraints listed in Table 1 are imposed [16].</p>
      <p>2.1.3. Cost constraint</p>
      <p>A user-defined budget constraint is introduced as an innovative aspect of this study. The user specifies the unit price   (per kg) for each material and the maximum allowable budget   is ensures that the optimized mixture maximizes compressive strength without exceeding the user’s budget.</p>
      <p>2.2.Implementation</p>
      <p>2.2.1. Framework description</p>
      <p>As illustrated in Fig. 2, the proposed framework operates as follows. The user, through an Android application, inputs the unit prices of the concrete constituents (cement, slag, fly ash, water, superplasticizer, coarse aggregate, and fine aggregate) along with the maximum allowable budget. This information is transmitted to a web server via an API. On the server, a machine learning model – trained on an experimental dataset – is hosted to predict the 28-day compressive strength of concrete for given inputs   through   Simultaneously, a genetic algorithm is implemented on the server, where the output of the machine learning model serves as the fitness function to be maximized. The genetic algorithm searches for optimal mixture proportions while satisfying the volume constraint, ratio constraints (e.g., water-to-binder ratio, slag-to-binder ratio, fly ash-to-binder ratio, coarse-to-total aggregate ratio, fine-to-binder ratio, and superplasticizer-to-cement ratio), and the budget.</p>
      <p>Finally, the genetic algorithm computes the optimal values of   that maximize the predicted compressive strength while ensuring that all constraints are satisfied. The optimized mix proportions are then returned to the Android application, enabling the user to conveniently view and utilize the results without requiring advanced knowledge of optimization methods.</p>
      <p>Figure 2. Framework of the proposed methodology.</p>
      <p>2.2.2. Modeling</p>
      <p>In this study, a dataset of 425 samples of high-performance concrete was employed for developing the machine learning model. The input features consisted of seven variables – cement, slag, fly ash, water, superplasticizer, coarse aggregate, and fine aggregate – while the output variable was the 28-day compressive strength. The experimental data were originally obtained from the program reported by Yeh [22], in which ASTM Type I Portland cement was used. Aggregate properties were described qualitatively, indicating that the coarse aggregate consisted of crushed natural stone with a maximum size of 10 mm, whereas the fine aggregate was washed river sand with a fineness modulus of approximately 3 mm. This dataset provided sufficient diversity to capture the variability in mixture proportions and their influence on compressive strength.</p>
      <p>To incorporate economic considerations, an additional column representing the cost of each mixture was computed using unit prices ($/kg) for all constituents: cement (0.11), slag (0.06), fly ash (0.055), water (0.000024), superplasticizer (2.94), coarse aggregate (0.01), and fine aggregate (0.006). Descriptive statistics for the dataset used in this study are presented in Table 2. The distributions of the input variables compressive strength and cost are shown in Fig. 3, illustrating the range and variability of the experimental data.</p>
      <p>Table 2. Descriptive statistics for the concrete dataset.</p>
      <p>mean</p>
      <p>std</p>
      <p>min</p>
      <p>25 %</p>
      <p>50 %</p>
      <p>75 %</p>
      <p>max</p>
      <p>Cement</p>
      <p>265.44</p>
      <p>104.67</p>
      <p>102.00</p>
      <p>160.20</p>
      <p>261.00</p>
      <p>323.70</p>
      <p>540.00</p>
      <p>Slag</p>
      <p>86.29</p>
      <p>87.83</p>
      <p>0.00</p>
      <p>0.00</p>
      <p>94.70</p>
      <p>160.50</p>
      <p>359.40</p>
      <p>Fly Ash</p>
      <p>62.80</p>
      <p>66.23</p>
      <p>0.00</p>
      <p>0.00</p>
      <p>60.00</p>
      <p>120.00</p>
      <p>200.10</p>
      <p>Water</p>
      <p>183.06</p>
      <p>19.33</p>
      <p>121.80</p>
      <p>171.00</p>
      <p>185.00</p>
      <p>193.30</p>
      <p>247.00</p>
      <p>Superplasticizer</p>
      <p>7.00</p>
      <p>5.39</p>
      <p>0.00</p>
      <p>0.00</p>
      <p>7.80</p>
      <p>10.30</p>
      <p>32.20</p>
      <p>Coarse Aggregate</p>
      <p>956.06</p>
      <p>83.80</p>
      <p>801.00</p>
      <p>882.60</p>
      <p>953.20</p>
      <p>1013.20</p>
      <p>1145.00</p>
      <p>Fine Aggregate</p>
      <p>764.38</p>
      <p>73.12</p>
      <p>594.00</p>
      <p>712.00</p>
      <p>769.30</p>
      <p>811.50</p>
      <p>992.60</p>
      <p>Compressive Strength</p>
      <p>36.75</p>
      <p>14.71</p>
      <p>8.54</p>
      <p>26.23</p>
      <p>33.76</p>
      <p>44.39</p>
      <p>81.75</p>
      <p>Cost</p>
      <p>72.55</p>
      <p>19.05</p>
      <p>34.93</p>
      <p>59.24</p>
      <p>72.07</p>
      <p>83.67</p>
      <p>166.86</p>
      <p>Figure 3. Histograms of input and output variables used in the study.</p>
      <p>The correlation map (Fig. 4) displays the pairwise Pearson correlation coefficients between the main concrete mix variables and cost. Strong positive correlations are observed between superplasticizer and cost, compressive strength and cement, and compressive strength and cost, indicating that higher amounts of superplasticizer and cement lead to increased compressive strength and higher overall cost 3C456E644E6F74653E3C436974653E3C417574686F723E4D613C2F417574686F723E3C596561723E323032333C2F596561723E3C5265634E756D3E3334353C2F5265634E756D3E3C446973706C6179546578743E5B32332D32365D3C2F446973706C6179546578743E3C7265636F72643E3C7265632D6E756D6265723E3334353C2F7265632D6E756D6265723E3C666F726569676E2D6B6579733E3C6B6579206170703D22454E222064622D69643D227A64766472707A3565767764786B65307372387078663563733272306678787378787435222074696D657374616D703D2231373634303535383735223E3334353C2F6B65793E3C2F666F726569676E2D6B6579733E3C7265662D74797065206E616D653D224A6F75726E616C2041727469636C65223E31373C2F7265662D747970653E3C636F6E7472696275746F72733E3C617574686F72733E3C617574686F723E4D612C204D696E677875653C2F617574686F723E3C617574686F723E54616D2C2056697669616E2057593C2F617574686F723E3C617574686F723E4C652C204B686F61204E3C2F617574686F723E3C617574686F723E4F7365692D4B7965692C20526F626572743C2F617574686F723E3C2F617574686F72733E3C2F636F6E7472696275746F72733E3C7469746C65733E3C7469746C653E416E616C7973696E672074686520696D7061637473206F66206B657920666163746F7273206F6E20746865207072696365206F662072656379636C656420636F6E63726574653A20412073797374656D2064796E616D696373206D6F64656C3C2F7469746C653E3C7365636F6E646172792D7469746C653E4A6F75726E616C206F66204275696C64696E6720456E67696E656572696E673C2F7365636F6E646172792D7469746C653E3C2F7469746C65733E3C706572696F646963616C3E3C66756C6C2D7469746C653E4A6F75726E616C206F66204275696C64696E6720456E67696E656572696E673C2F66756C6C2D7469746C653E3C2F706572696F646963616C3E3C70616765733E3130383132333C2F70616765733E3C766F6C756D653E38303C2F766F6C756D653E3C64617465733E3C796561723E323032333C2F796561723E3C2F64617465733E3C6973626E3E323335322D373130323C2F6973626E3E3C75726C733E3C2F75726C733E3C2F7265636F72643E3C2F436974653E3C436974653E3C417574686F723E4B68616E3C2F417574686F723E3C596561723E323031363C2F596561723E3C5265634E756D3E3334363C2F5265634E756D3E3C7265636F72643E3C7265632D6E756D6265723E3334363C2F7265632D6E756D6265723E3C666F726569676E2D6B6579733E3C6B6579206170703D22454E222064622D69643D227A64766472707A3565767764786B65307372387078663563733272306678787378787435222074696D657374616D703D2231373634303536313032223E3334363C2F6B65793E3C2F666F726569676E2D6B6579733E3C7265662D74797065206E616D653D224A6F75726E616C2041727469636C65223E31373C2F7265662D747970653E3C636F6E7472696275746F72733E3C617574686F72733E3C617574686F723E4B68616E2C2041736164757A7A616D616E3C2F617574686F723E3C617574686F723E446F2C204A656F6E6779756E3C2F617574686F723E3C617574686F723E4B696D2C20446F6F6B69653C2F617574686F723E3C2F617574686F72733E3C2F636F6E7472696275746F72733E3C7469746C65733E3C7469746C653E436F737420656666656374697665206F7074696D616C206D69782070726F706F7274696F6E696E67206F66206869676820737472656E6774682073656C6620636F6D70616374696E6720636F6E6372657465207573696E6720726573706F6E73652073757266616365206D6574686F646F6C6F67793C2F7469746C653E3C7365636F6E646172792D7469746C653E436F6D70757465727320616E6420436F6E63726574653C2F7365636F6E646172792D7469746C653E3C2F7469746C65733E3C706572696F646963616C3E3C66756C6C2D7469746C653E436F6D70757465727320616E6420436F6E63726574653C2F66756C6C2D7469746C653E3C2F706572696F646963616C3E3C70616765733E3632392D3633383C2F70616765733E3C766F6C756D653E31373C2F766F6C756D653E3C6E756D6265723E353C2F6E756D6265723E3C64617465733E3C796561723E323031363C2F796561723E3C2F64617465733E3C6973626E3E313539382D383139383C2F6973626E3E3C75726C733E3C2F75726C733E3C2F7265636F72643E3C2F436974653E3C436974653E3C417574686F723E43617675736F676C753C2F417574686F723E3C596561723E323032343C2F596561723E3C5265634E756D3E3334373C2F5265634E756D3E3C7265636F72643E3C7265632D6E756D6265723E3334373C2F7265632D6E756D6265723E3C666F726569676E2D6B6579733E3C6B6579206170703D22454E222064622D69643D227A64766472707A3565767764786B65307372387078663563733272306678787378787435222074696D657374616D703D2231373634303536313636223E3334373C2F6B65793E3C2F666F726569676E2D6B6579733E3C7265662D74797065206E616D653D224A6F75726E616C2041727469636C65223E31373C2F7265662D747970653E3C636F6E7472696275746F72733E3C617574686F72733E3C617574686F723E43617675736F676C752C204962726168696D3C2F617574686F723E3C2F617574686F72733E3C2F636F6E7472696275746F72733E3C7469746C65733E3C7469746C653E5375706572706C6173746963697A657220446F7361676520456666656374206F6E20537472656E6774682C204D6963726F73747275637475726520616E64205065726D656162696C69747920456E68616E63656D656E74206F662043656D656E746974696F75732050617374652046696C6C733C2F7469746C653E3C7365636F6E646172792D7469746C653E4D696E6572616C732028323037352D31363358293C2F7365636F6E646172792D7469746C653E3C2F7469746C65733E3C706572696F646963616C3E3C66756C6C2D7469746C653E4D696E6572616C732028323037352D31363358293C2F66756C6C2D7469746C653E3C2F706572696F646963616C3E3C766F6C756D653E31343C2F766F6C756D653E3C6E756D6265723E31323C2F6E756D6265723E3C64617465733E3C796561723E323032343C2F796561723E3C2F64617465733E3C6973626E3E323037352D313633583C2F6973626E3E3C75726C733E3C2F75726C733E3C2F7265636F72643E3C2F436974653E3C436974653E3C417574686F723E416C73616465793C2F417574686F723E3C596561723E323032323C2F596561723E3C5265634E756D3E3334383C2F5265634E756D3E3C7265636F72643E3C7265632D6E756D6265723E3334383C2F7265632D6E756D6265723E3C666F726569676E2D6B6579733E3C6B6579206170703D22454E222064622D69643D227A64766472707A3565767764786B65307372387078663563733272306678787378787435222074696D657374616D703D2231373634303537353038223E3334383C2F6B65793E3C2F666F726569676E2D6B6579733E3C7265662D74797065206E616D653D224A6F75726E616C2041727469636C65223E31373C2F7265662D747970653E3C636F6E7472696275746F72733E3C617574686F72733E3C617574686F723E416C73616465792C2053616C6168616C6465696E3C2F617574686F723E3C617574686F723E4F6D72616E2C20416264656C6E617365723C2F617574686F723E3C2F617574686F72733E3C2F636F6E7472696275746F72733E3C7469746C65733E3C7469746C653E456666656374206F66207375706572706C6173746963697A65727320746F20656E68616E6365207468652070726F70657274696573206F6620636F6E63726574653C2F7469746C653E3C7365636F6E646172792D7469746C653E4465732E20436F6E7374722E204D61696E743C2F7365636F6E646172792D7469746C653E3C2F7469746C65733E3C706572696F646963616C3E3C66756C6C2D7469746C653E4465732E20436F6E7374722E204D61696E743C2F66756C6C2D7469746C653E3C2F706572696F646963616C3E3C70616765733E38342D39313C2F70616765733E3C766F6C756D653E323C2F766F6C756D653E3C64617465733E3C796561723E323032323C2F796561723E3C2F64617465733E3C75726C733E3C2F75726C733E3C2F7265636F72643E3C2F436974653E3C2F456E644E6F74653E00 [23–26].</p>
      <p>Figure 4. Correlation map of concrete mix variables and cost.</p>
      <p>Three different machine learning models were considered: extreme gradient boosting [19], multilayer perceptron neural network [27], and random forest [28]. To ensure robust evaluation, a 10-fold cross-validation approach was employed during training. Model performance was compared using the mean squared error metric.</p>
      <p>2.2.3. Optimization</p>
      <p>Genetic algorithm is an evolutionary optimization technique inspired by the process of natural selection [29]. It operates by encoding potential solutions, known as chromosomes, and evolving them over successive generations to find the optimal solution. In the present study, each chromosome represents a possible concrete mixture, defined by the seven input variables   (cement, slag, fly ash, water, superplasticizer, coarse aggregate, and fine aggregate). The fitness of each chromosome is evaluated using the trained machine learning model, which predicts the 28-day compressive strength, while budget and proportional constraints are simultaneously enforced. As illustrated in Fig. 5, the genetic algorithm applies selection to retain high-performing chromosomes, crossover to recombine parent solutions, and mutation to introduce diversity and avoid premature convergence. Through iterative search of the solution space, the genetic algorithm gradually improves the population until the optimal mix proportions that maximize compressive strength without exceeding the budget are obtained.</p>
      <p>Figure 5. Schematic representation of the genetic algorithm framework.</p>
      <p>2.2.4. Implementation and deployment</p>
      <p>After the machine learning model was trained and saved, it was deployed on the PythonAnywhere hosting platform. Along with the trained model, the genetic algorithm code was also implemented on the same host. To enable practical use, an Android application was developed using App Inventor, through which users could provide unit prices of concrete components and the maximum allowable budget. These inputs were transmitted via an API to the server. The Flask framework was employed to handle communication, ensuring efficient transfer of requests and responses between the application and the server. On the server side, the genetic algorithm utilized the user-provided information together with the trained machine learning model to compute the optimal mix proportions   The optimization process was carried out with the objective of maximizing compressive strength without exceeding the specified budget. Finally, the computed optimal proportions and the corresponding compressive strength were returned to the Android application through the API, enabling the user to conveniently access and interpret the results.</p>
      <p>3.Results and Discussion</p>
      <p>&lt; &gt;Modeling Results</p>
      <p>Metrics and hyperparameters</p>
      <p>Value</p>
      <p>max_depth</p>
      <p>4</p>
      <p>n_estimators</p>
      <p>500</p>
      <p>Mean Squared Error</p>
      <p>17.56</p>
      <p>Root Mean Squared Error</p>
      <p>4.19</p>
      <p>Mean Absolute Error</p>
      <p>2.82</p>
      <p>R-squared</p>
      <p>0.93</p>
      <p> </p>
      <p>&lt; &gt;Genetic Algorithm</p>
      <p> </p>
      <p>Figure 6. Pseudocode of the server-side implementation of the genetic algorithm integrated
with the trained machine learning model and Flask framework.</p>
      <p>&lt; &gt;Practical Implementation</p>
      <p> </p>
      <p>Figure 7. Schematic representation of the developed framework integrating
the Android application with the Flask-based server on PythonAnywhere.</p>
      <p>In Fig. 8, the essential App Inventor blocks required for developing the Android application are illustrated. Two groups of blocks can be observed. The blocks on the left are responsible for sending the input information provided by the user – including the unit prices of concrete components and the maximum allowable budget – to the server. The blocks on the right handle the response received from the server, which contains the optimized mixture proportions of the seven components within the specified budget. Additionally, these blocks display the corresponding 28-day compressive strength predicted by the trained machine learning model for the optimized mixture design.</p>
      <p>Figure 8. App Inventor blocks used in the Android application.</p>
      <p>4.Conclusion</p>
      <p>In this study, a machine learning-guided optimization framework was developed to design cost-effective and high-performance concrete mixtures. An XGBoost model was trained on an experimental dataset of 425 samples to accurately predict the 28-day compressive strength of concrete. The trained model was then integrated with a genetic algorithm to optimize mixture proportions under adaptive cost constraints, allowing flexible consideration of varying market conditions. Unlike conventional multi-objective approaches that simultaneously optimize strength and cost, this study formulated the problem as a single-objective optimization with compressive strength maximization, while cost was incorporated as a constraint. This approach enables practical adaptability while ensuring budget limits are not exceeded.</p>
      <p>To bridge the gap between theory and practice, an Android application was developed using App Inventor. The application allows users to input unit prices of components and defines budget limits, which are then transmitted to a server hosting the machine learning model and genetic algorithm implemented via Flask. The server computes optimized mixture proportions and returns both the mix design and predicted compressive strength to the user interface. This practical implementation demonstrates the usability of the framework even for non-expert users, supporting data-driven decision-making in construction material design.</p>
      <p>An important advantage of the proposed framework lies in its adaptability to real-world economic conditions. In scenarios where market prices of materials fluctuate, the system can seamlessly adjust optimization results according to updated unit prices. Similarly, when project budgets vary – ranging from generous allocations to highly cost-sensitive cases – the framework can readily adapt to provide optimized designs that meet the specified financial constraints. This flexibility makes the proposed approach highly practical and valuable for real construction applications where both material costs and budget availability are inherently dynamic.</p>
      <p>Moreover, unlike multi-objective approaches that typically generate a large set of non-dominated solutions (Pareto front), which may cause confusion for practitioners in selecting the most suitable mix design, the single-objective formulation adopted here provides a unique optimal solution. This simplifies the decision-making process by directly identifying the best mix design under the specified budget, thereby enhancing the usability of the framework in practical scenarios.</p>
      <p>Workability, commonly quantified by slump, is a critical performance requirement for concrete mixtures, as it directly affects placing, compaction, and overall constructability, particularly in high-strength concrete. Future work may extend the proposed framework by incorporating concrete workability as a constraint rather than as an additional optimization objective. This can be achieved by developing a dedicated machine learning model to predict slump based on mixture proportions. During the optimization process, the objective function would remain the maximization of compressive strength, while a minimum target slump value would be imposed as a constraint. Such a constrained optimization strategy would ensure that the optimized concrete mixtures achieve high strength while maintaining adequate workability, thereby enhancing the practical applicability of the proposed framework.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <title>References</title>
      <ref id="ref1">
        <mixed-citation publication-type="journal">Neville, A.M. Properties of concrete. 4th edn. Longman. Essex, 1995. 844 p.</mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation publication-type="journal">Mehta, P.K., Monteiro, P.J. Concrete microstructure, properties, and materials.: McGraw-Hill. 3rd edn. McGraw-Hill. New York, 2006. 684 p.</mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation publication-type="journal">Abolpour, B., Afsahi, M.M., Hosseini, S.G. Statistical analysis of the effective factors on the 28 days compressive strength and setting time of the concrete. Journal of Advanced Research. 2015. 6(5). Pp. 699–709. DOI: 10.1016/j.jare.2014.03.005</mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation publication-type="journal">Abd Elaty, M.A.A. Compressive strength prediction of Portland cement concrete with age using a new model. HBRC Journal. 2014. 10(2). Pp. 145–155. DOI: 10.1016/j.hbrcj.2013.09.005</mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation publication-type="journal">Amin, M.N., Iftikhar, B., Kaffayatullah, Kh., and Qadir, M.T. Analyzing the compressive strength, eco-strength, and cost–strength ratio of agro-waste-derived concrete using advanced machine learning methods. Reviews on Advanced Materials Science. 2025. 64(1). Article no. 20250091. DOI: 10.1515/rams-2025-0091</mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation publication-type="journal">Ramseyer, C.C., Kiamanesh, R. Optimizing Concrete Mix Designs to Produce Cost Effective Paving Mixes. Oklahoma Department of Transportation. 2009. 122 p.</mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation publication-type="journal">Zheng, W., Zheng, W., Shui, Zh., Xu, Zh., Gao, Xu, Zhang, Sh. Multi-objective optimization of concrete mix design based on machine learning. Journal of Building Engineering. 2023. 76. Article no. 107396. DOI: 10.1016/j.jobe.2023.107396</mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation publication-type="journal">Tipu, R.K., Panchal, V., Pandya, K. Multi-objective optimized high-strength concrete mix design using a hybrid machine learning and metaheuristic algorithm. Asian Journal of Civil Engineering. 2023. 24(3). Pp. 849–867. DOI: 10.1007/s42107-022-00535-8</mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation publication-type="journal">Wang, M., Wang, M., Du, M., Zhuang, X., x Lv, X., Wang, Ch., Zh. Multi-objective optimization of ultra-high performance concrete based on life-cycle assessment and machine learning methods. Frontiers of Structural and Civil Engineering. 2025. 19(1). Pp. 143–161. DOI: 10.1007/s11709-025-1152-0</mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation publication-type="journal">Zhang, F., Wen, B., Niu, D., Li, A., &amp; Guo, B. Optimized Design of Low-Carbon Mix Ratio for Non-Dominated Sorting Genetic Algorithm II Concrete Based on Genetic Algorithm-Improved Back Propagation. Materials. 2024. 17(16). Article no. 4077. DOI: 10.3390/ma17164077</mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation publication-type="journal">DeRousseau, M., Kasprzyk, J., Srubar III, W. Multi-objective optimization methods for designing low-carbon concrete mixtures. Frontiers in Materials. 2021. 8. Article no. 680895. DOI: 10.3389/fmats.2021.680895</mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation publication-type="journal">Wei, J., Zhang, H., Yang, Y., Zhang W., Liu, X. Multi-objective optimization of compressive strength and slump in MPCM-integrated concrete using machine learning. Materials Today Communications. 2025. 46. Article no. 112619. DOI: 10.1016/j.mtcomm.2025.112619</mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation publication-type="journal">Gu, Y., Fan, R., Li, Y., Zhao, J., Song, Z., Chu, H. Multi-Objective Optimization for Nano-Silica-Modified Concrete Based on Explainable Machine Learning. Nanomaterials. 2025. 15(18). Article no. 1423. DOI: 10.3390/nano15181423</mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation publication-type="journal">Chen, F., Xu, W., Wen, Q., Zhang, G., Xu, L., Fan, D., Yu, R. Advancing concrete mix proportion through hybrid intelligence: A multi-objective optimization approach. Materials. 2023. 16(19). Article no. 6448. DOI: 10.3390/ma16196448</mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation publication-type="journal">Fan, M., Li, Y., Shen., J., J., Kaikai, Shi, J. Multi-objective optimization design of recycled aggregate concrete mixture proportions based on machine learning and NSGA-II algorithm. Advances in Engineering Software. 2024. 192. Article no. 103631. DOI: 10.1016/j.advengsoft.2024.103631</mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation publication-type="journal">Zhang, J., Huang, Y., Wang, Y., Ma, G. Multi-objective optimization of concrete mixture proportions using machine learning and metaheuristic algorithms. Construction and Building Materials. 2020. 253. Article no. 119208. DOI: 10.1016/j.conbuildmat.2020.119208</mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation publication-type="journal">Tipu, R.K., Rathi, P., Pandya, K., Panchal, V.R. Optimizing sustainable blended concrete mixes using deep learning and multi-objective optimization. Scientific Reports. 2025. 15(1). Article no. 16356. DOI: 10.1038/s41598-025-00943-1</mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation publication-type="journal">Paudel, S., Pudasaini, A., Shrestha, R.K., Kharel, E. Compressive strength of concrete material using machine learning techniques. Cleaner Engineering and Technology. 2023. 15. Article no. 100661. DOI: 10.1016/j.clet.2023.100661</mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation publication-type="journal">Abbas, Y.M., Khan, M.I. Robust Machine Learning Framework for Modeling the Compressive Strength of SFRC: Database Compilation, Predictive Analysis, and Empirical Verification. Materials. 2023. 16(22). Article no. 7178. DOI: 10.3390/ma16227178</mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation publication-type="journal">Oviedo, A.I., Londoño, J.M., Vargas, J.F., Zuluaga, C., Gómez, A. Modeling and Optimization of Concrete Mixtures Using Machine Learning Estimators and Genetic Algorithms. Modelling. 2024. 5(3). Article no. 642–658. DOI: 10.3390/modelling5030034</mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation publication-type="journal">Zuo, S., Liu, B. Optimization design of concrete mix proportion based on support vector machine regression and enhanced genetic algorithm. Discover Applied Sciences. 2025. 7(3). Article no. 200. DOI: 10.1007/s42452-025-06603-3</mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation publication-type="journal">Yeh, I.-C. Design of high-performance concrete mixture using neural networks and nonlinear programming. Journal of Computing in Civil Engineering. 1999. 13(1). Pp. 36–42.</mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation publication-type="journal">Ma, M., Tam, V.W., Le, Kh.N., Osei-Kyei, R. Analysing the impacts of key factors on the price of recycled concrete: A system dynamics model. Journal of Building Engineering. 2023. 80. Article no. 108123. DOI: 10.1016/j.jobe.2023.108123</mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation publication-type="journal">Khan, A., Do, J., Kim, D. Cost effective optimal mix proportioning of high strength self compacting concrete using response surface methodology. Computers and Concrete. 2016. 17(5). Pp. 629–638. DOI: 10.12989/cac.2016.17.5.629</mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation publication-type="journal">Cavusoglu, I. Superplasticizer Dosage Effect on Strength, Microstructure and Permeability Enhancement of Cementitious Paste Fills. Minerals. 2024. 14(12). Article no. 1242. DOI: 10.3390/min14121242</mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation publication-type="journal">Alsadey, S., Omran, A. Effect of superplasticizers to enhance the properties of concrete. Design, Construction, Maintenance. 2022. 2. Pp. 84–91. DOI: 10.37394/232022.2022.2.13</mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation publication-type="journal">Asteris, P.G., et al. AI-powered GUI for prediction of axial compression capacity in concrete-filled steel tube columns. Neural Computing and Applications. 2024. 36(35). Article no. 22429–22459. DOI: 10.1007/s00521-024-10405-w</mixed-citation>
      </ref>
      <ref id="ref28">
        <mixed-citation publication-type="journal">Li, H., Lin, J., Lei, X., Wei, T. Compressive strength prediction of basalt fiber reinforced concrete via random forest algorithm. Materials Today Communications. 2022. 30. Article no. 103117. DOI: 10.1016/j.mtcomm.2021.103117</mixed-citation>
      </ref>
      <ref id="ref29">
        <mixed-citation publication-type="journal">Holand, J.H. Adaptation in Natural and Artificial Systems: An Introductory Analysis with Applications to Biology, Control, and Artificial Intelligence. The University of Michigan Press. Ann Arbor, MI, 1975. 232 p.</mixed-citation>
      </ref>
      <ref id="ref30">
        <mixed-citation publication-type="journal">Nukah, P.D., Abbey, S.J., Booth, C.A. Development of a learner model tool for predicting strength and embodied carbon for lightweight concrete production. Journal of Building Engineering. 2024. 95. Article no. 110330. DOI: 10.1016/j.jobe.2024.110330</mixed-citation>
      </ref>
      <ref id="ref31">
        <mixed-citation publication-type="journal">Abdennaji, T.S., Tipu, R.K., Alassaf, Y. Predicting compressive and tensile strength of concrete with different sand types using machine learning. Ain Shams Engineering Journal, 2025. 16(8). Article no. 103474. DOI: 10.1016/j.asej.2025.103474</mixed-citation>
      </ref>
      <ref id="ref32">
        <mixed-citation publication-type="journal">Golafshani, E., Khodadadi, N., Ngo, T., Nanni, A., Behnood, A. Modelling the compressive strength of geopolymer recycled aggregate concrete using ensemble machine learning. Advances in Engineering Software. 2024. 191. DOI: 10.1016/j.advengsoft.2024.103611</mixed-citation>
      </ref>
      <ref id="ref33">
        <mixed-citation publication-type="journal">Fathy, I.N., Dahish, H.A., Alkharisi, M.K., Mahmoud, A.A., Fouad, H.E.E. Predicting the compressive strength of concrete incorporating waste powders exposed to elevated temperatures utilizing machine learning. Scientific Reports. 2025. 15(1). Article no. 25275. DOI: 10.1038/s41598-025-11239-9</mixed-citation>
      </ref>
      <ref id="ref34">
        <mixed-citation publication-type="journal">Shaaban, M., Amin, M., Selim, S., Riad, I.M. Machine learning approaches for forecasting compressive strength of high-strength concrete. Scientific Reports. 2025. 15(1). Article no. 25567. DOI: 10.1038/s41598-025-10342-1</mixed-citation>
      </ref>
      <ref id="ref35">
        <mixed-citation publication-type="journal">Chou, J.-S., Chen, L.-Y., Liu, C.-Y. Forensic-based investigation-optimized extreme gradient boosting system for predicting compressive strength of ready-mixed concrete. Journal of Computational Design and Engineering. 2023. 10(1). Pp. 425–445. DOI: 10.1093/jcde/qwac133</mixed-citation>
      </ref>
      <ref id="ref36">
        <mixed-citation publication-type="journal">Cihan, M.T., Cihan, P. Bayesian-Optimized Ensemble Models for Geopolymer Concrete Compressive Strength Prediction with Interpretability Analysis. Buildings. 2025. 15(20). Article no. 3667. DOI: 10.3390/buildings15203667</mixed-citation>
      </ref>
      <ref id="ref37">
        <mixed-citation publication-type="journal">Philip, S., Nidhi, N. Compressive strength prediction and feature analysis for GGBS-Based geopolymer concrete using optimized XGBoost and SHAP: A comparative study of optimization algorithms and experimental validation. Journal of Building Engineering. 2025. 108. Article no. 112879. DOI: 10.1016/j.jobe.2025.112879</mixed-citation>
      </ref>
      <ref id="ref38">
        <mixed-citation publication-type="journal">Khan, M.I., Abbas, Y.M., Fares, G., Alqahtani, F. Strength prediction and optimization for ultrahigh-performance concrete with low-carbon cementitious materials – XG boost model and experimental validation. Construction and Building Materials. 2023. 387. Article no. 131606. DOI: 10.1016/j.conbuildmat.2023.131606</mixed-citation>
      </ref>
      <ref id="ref39">
        <mixed-citation publication-type="journal">Tabani, A., Sharma, A., Biswas, R., Sivenas, T., Asteris, P.G. Revealing the nature of Ultra-High-Performance concrete using computational intelligence. Construction and Building Materials. 2025. 492. Article no. 143082. DOI: 10.1016/j.conbuildmat.2025.143082</mixed-citation>
      </ref>
      <ref id="ref40">
        <mixed-citation publication-type="journal">Al-Naghi, A.A., Ahmad, A., Amin, M.N., Algassem, O., Alnawmasi, N. Sustainable optimisation of GGBS-based concrete: De-risking mix design through predictive machine learning models. Case Studies in Construction Materials. 2025. 23. Article no. e04900. DOI: 10.1016/j.cscm.2025.e04900</mixed-citation>
      </ref>
      <ref id="ref41">
        <mixed-citation publication-type="journal">Cakiroglu, C., Batool, F., Sangi, A.J., Fatima, B., Nehdi, M.L. Explainable machine learning predictive model for mechanical strength of recycled ceramic tile-based concrete. Materials Today Communications. 2025. 44. Article no. 112139. DOI: 10.1016/j.mtcomm.2025.112139</mixed-citation>
      </ref>
      <ref id="ref42">
        <mixed-citation publication-type="journal">Ehsan, K., Mohamed, A.H., Inqiad, W.B., Javed, M.A., Iqbal, I. Multi expression programming and interpretable machine learning for determining compressive strength of coral sand aggregate concrete. Materials Today Communications. 2025. 45. Article no. 112370. DOI: 10.1016/j.mtcomm.2025.112370</mixed-citation>
      </ref>
      <ref id="ref43">
        <mixed-citation publication-type="journal">Hamed, A.K., Elshaarawy, M.K., Alsaadawi, M.M. Stacked-based machine learning to predict the uniaxial compressive strength of concrete materials. Computers and Structures. 2025. 308. Article no. 107644. DOI: 10.1016/j.compstruc.2025.107644</mixed-citation>
      </ref>
      <ref id="ref44">
        <mixed-citation publication-type="journal">Abushanab, A., Vimonsatit, V. Compressive strength, flexural strength, and slump of recycled aggregate fibre-reinforced fly ash concrete using explainable extreme gradient boosting machine learning model with prediction tool. Powder Technology. 2025. 469(1). Article no. 121710. DOI: 10.1016/j.powtec.2025.121710</mixed-citation>
      </ref>
      <ref id="ref45">
        <mixed-citation publication-type="journal">Alahmari, T.S., Arif, K. Machine learning approaches to predict the strength of graphene nanoplatelets concrete: Optimization and hyper tuning with graphical user interface. Materials Today Communications. 2024. 40. Article no. 109946. DOI: 10.1016/j.mtcomm.2024.109946</mixed-citation>
      </ref>
      <ref id="ref46">
        <mixed-citation publication-type="journal">Kapil, A., Jadda, K., Jee, A.A. Developing machine learning models to predict the fly ash concrete compressive strength. Asian Journal of Civil Engineering. 2024. 25(7). Article no. 5505–5523. DOI: 10.1007/s42107-024-01125-6</mixed-citation>
      </ref>
      <ref id="ref47">
        <mixed-citation publication-type="journal">Javed, M.F., Fawad, M., Lodhi, R., Najeh, T., Gamil, Y. Forecasting the strength of preplaced aggregate concrete using interpretable machine learning approaches. Scientific Reports. 2024. 14(1). Article no. 8381. DOI: 10.1038/s41598-024-57896-0</mixed-citation>
      </ref>
      <ref id="ref48">
        <mixed-citation publication-type="journal">Khatoon, S., K, K.A., Sapkota, S.C. Experimental insights and hybridized ensemble machine learning validation of fiber reinforced geopolymer concrete strength. Asian Journal of Civil Engineering. 2026. 27. Pp. 1289–1312. DOI: 10.1007/s42107-025-01562-x</mixed-citation>
      </ref>
      <ref id="ref49">
        <mixed-citation publication-type="journal">Li, T., Yang, J., Jiang, P., Abuhussain, M.A., Zaman, A., Fawad, M., Farooq, F. Forecasting the strength of nanocomposite concrete containing carbon nanotubes by interpretable machine learning approaches with graphical user interface. Structures. 2024. 59. Article no. 105821. DOI: 10.1016/j.istruc.2023.105821</mixed-citation>
      </ref>
      <ref id="ref50">
        <mixed-citation publication-type="journal">Liu, X., Mei, Sh., Wang, X., Li, X. Estimation of compressive strength of concrete with manufactured sand and natural sand using interpretable artificial intelligence. Case Studies in Construction Materials. 2024. 21. Article no. e03840. DOI: 10.1016/j.cscm.2024.e03840</mixed-citation>
      </ref>
      <ref id="ref51">
        <mixed-citation publication-type="journal">Nguyen, N.H., Abellán-García, J., Lee, S., Garcia-Castano, E, Vo. Th.P. Efficient estimating compressive strength of ultra-high performance concrete using XGBoost model. Journal of Building Engineering. 2022. 52. Article no. 104302. DOI: 10.1016/j.jobe.2022.104302</mixed-citation>
      </ref>
      <ref id="ref52">
        <mixed-citation publication-type="journal">Sun, Y. Explainable Prediction of Compressive Strength and Elastic Modulus for Concrete Containing Waste Foundry Sand Using Bayesian-Optimized XGBoost with 10-Fold Cross-Validation. Journal of Sustainable Metallurgy. 2024. 10(1). Pp. 335–359. DOI: 10.1007/s40831-024-00790-w</mixed-citation>
      </ref>
      <ref id="ref53">
        <mixed-citation publication-type="journal">Singh, S., Patro, S.K., Parhi, S.K. Evolutionary optimization of machine learning algorithm hyperparameters for strength prediction of high-performance concrete. Asian Journal of Civil Engineering. 2023. 24(8). Pp. 3121–3143. DOI: 10.1007/s42107-023-00698-y</mixed-citation>
      </ref>
      <ref id="ref54">
        <mixed-citation publication-type="journal">Sun, Y. Estimation of compressive strength for spiral stirrup-confined circular concrete column using optimized machine learning with interpretable techniques. Mechanics of Advanced Materials and Structures. 2024. 31(28). Pp. 10839–10858. DOI: 10.1080/15376494.2023.2298232</mixed-citation>
      </ref>
      <ref id="ref55">
        <mixed-citation publication-type="journal">Ullah, A., Yang,Y., Ullah, W., Ayub, B., Alzlfawi, A., Iqbal, I. Toward transparent AI: Predicting strength of fly ash foam composite concrete using explainable ML models. Structural Concrete. 2025. 27(1). Pp. 595–624. DOI: 10.1002/suco.70302</mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>
